My radon just spiked to 12 pCi/L for one night. Does that mean I have a problem?
One night at 12 pCi/L is worth paying attention to, but it doesn't automatically mean your long-term average is that high. Radon fluctuates - barometric pressure, wind, temperature, and whether your windows were open all affect what the monitor sees on any given night. What matters is the long-term average, ideally over 90 days or more in the lowest livable area of your home. Even so, a spike that high usually means there's a meaningful radon source below your slab, so it's worth watching the trend. If the average keeps climbing, that's when you act.
#p3-workflow-readings-spikes-interpretation-0001My radon went up to 20 pCi/L overnight. Is that possible?
Yes, it's possible, and it doesn't mean your house is falling apart. Short-term spikes can be dramatic - a closed-up basement during a pressure drop, a storm rolling through, a humid night with no airflow. The sensor is doing its job; it's just catching a moment when conditions pushed radon up aggressively. The number that drives your decision should be the 90-day or long-term average, not a single overnight peak. If you're seeing frequent nights above 10 pCi/L though, that's a signal worth taking seriously.
#p3-workflow-readings-spikes-interpretation-0002My monitor showed 8 pCi/L for one hour and then came back down to 2.5. Should I be worried?
That kind of swing is more common than people expect. Radon readings at the hourly level are noisy - the sensor is working with a small sample of air, and localized factors like someone opening a door, a pressure change, or a heating cycle kicking on can all move the number. The one-hour reading at 8 pCi/L is real data, but it's not your whole picture. Watch what your 7-day and long-term averages do over the coming weeks. If those stay under 4.0, you're probably seeing normal fluctuation.
#p3-workflow-readings-spikes-interpretation-0003My radon spiked to 15 pCi/L for two days straight. Is that a crisis?
Two straight days above 10 pCi/L is a notable data point, not a crisis, but it does suggest you have a meaningful radon source in the ground beneath your home. Radon at those levels consistently would be a reason to mitigate. At this point, I'd want to know what your long-term average looks like - if you've been under 4.0 for months and this is a weather-related spike, it's different than if your baseline has been creeping up. Either way, this is worth a conversation.
#p3-workflow-readings-spikes-interpretation-0004My Airthings hit 25 pCi/L last night and I'm freaking out. What do I do?
Take a breath. That reading is alarming to see on a screen, but one night at 25 pCi/L does not mean you've been living in a high-radon house for months. Radon risk is about cumulative exposure over years, not a single bad night. Check your 7-day and long-term averages - those are what actually reflect your real exposure. If the long-term average is well below 4.0 pCi/L, last night was likely an anomaly driven by weather or pressure. If the long-term average is also high, then yes, you need mitigation. But either way, you have time to get the right information before doing anything.
#p3-workflow-readings-spikes-interpretation-0005My radon jumped from 2 to 9 in a single day. What causes that kind of jump?
Barometric pressure is usually the culprit. When pressure drops rapidly - ahead of a storm front - the soil beneath your slab releases radon faster, and your basement essentially acts like a vacuum pulling it in. You can sometimes predict these spikes by watching the weather forecast. A sudden weather system, high winds, or a cold front can all cause dramatic short-term spikes even in homes where radon is otherwise manageable. Look at your long-term average to put this in context.
#p3-workflow-readings-spikes-interpretation-0006My radon was 3.0 for two weeks then shot up to 11 pCi/L for three days and went back down. What happened?
Almost certainly a weather event. That kind of pattern - baseline, spike, return to baseline - is textbook pressure-drop behavior. The three-day window usually lines up with a storm system moving through or a period of low barometric pressure. It's genuine radon coming out of the ground; the conditions just temporarily amped up how much was entering the house. Your long-term average is the number to watch. If that stays under 4.0, this was normal variability. If it keeps inching upward, that's a different story.
#p3-workflow-readings-spikes-interpretation-0007I have a finished basement and my radon hit 18 pCi/L for two days. Do I need to evacuate?
No, you do not need to evacuate. Radon is a long-term lung-cancer risk from cumulative radiation exposure over years - two days at 18 pCi/L does not cause acute harm. Even so, if your long-term average is also elevated, mitigation should be on your near-term list. There's no need to panic, but there is good reason to get more data and take action if the averages confirm the problem. Call or text and we can look at what your numbers mean for your situation.
#p3-workflow-readings-spikes-interpretation-0008My radon spiked the night I ran a space heater in the basement. Did the heater cause it?
Not directly. Space heaters can affect airflow and depressurization in a basement - they draw air upward as heat rises, which can pull more radon-laden air in from the soil. It's less about the heater itself and more about how the heating cycle changes the air pressure dynamics in the space. One night isn't enough to draw conclusions, but it's worth noting the pattern. If running the heater consistently produces higher readings, that's useful information about how your basement breathes.
#p3-workflow-readings-spikes-interpretation-0009My radon spiked to 7 pCi/L the night I had a lot of people over in the basement. Could people cause a radon spike?
A houseful of people won't directly cause a radon spike, but activity in the basement can change airflow in ways that affect readings. People moving around, doors opening and closing, and HVAC systems cycling differently can all influence what the monitor sees. A more likely explanation is that the gathering happened to coincide with a pressure or weather change. Look at your long-term average to see whether the baseline is actually elevated.
#p3-workflow-readings-spikes-interpretation-0010My radon was 0.4 for months, then hit 6.2 last week. Is my monitor broken?
It might be, but it's also possible the reading is real. Radon can genuinely spike with weather events, and a monitor that's been running on the low end isn't immune to that. Check whether the timing lines up with a storm, a cold snap, or a change in how the house was ventilated. If the spike was brief and the reading came back down close to 0.4, the monitor is probably working fine. If it's stayed elevated and the numbers don't make sense, Airthings and other manufacturers have troubleshooting steps - or you can run a short-term test kit alongside it to compare.
#p3-workflow-readings-spikes-interpretation-0011My monitor showed 0.0 pCi/L for the first two weeks and now it's showing 4.5. Is the monitor malfunctioning?
It's unlikely to be a malfunction. The first week or two of readings on a new monitor are often lower or less stable because the sensor is still calibrating and accumulating data. Consumer radon monitors - including Airthings - tend to show more accurate averages after 30+ days of operation. The 4.5 reading after a couple weeks may actually be closer to your true average. If you're concerned, watch the trend over the next month and see where the long-term average settles.
#p3-workflow-readings-spikes-interpretation-0012My radon reading jumped to 9 pCi/L and there was a big thunderstorm that night. Is that a coincidence?
Almost certainly not a coincidence. Thunderstorms are associated with rapid barometric pressure drops, which are one of the most reliable drivers of short-term radon spikes in basements. The drop in pressure effectively lets the soil beneath the slab "breathe" more aggressively, pushing radon upward. This is normal geophysical behavior - not a sign your house has a sudden new radon problem. Your long-term average is the number that actually reflects your exposure level.
#p3-workflow-readings-spikes-interpretation-0013My radon spiked to 11 pCi/L for a week and then dropped back down to 2.8. Should I still mitigate?
A full week at 11 pCi/L is more than a one-night anomaly, but coming back down to 2.8 is a good sign that the spike was weather-driven rather than structural. If your long-term average is landing under 4.0 pCi/L, the EPA guidance doesn't require mitigation - but the EPA also acknowledges that any level above 2.0 carries some risk worth considering. The frequency and duration of spikes like that one does factor into your cumulative exposure over time. Worth a conversation if you want to think it through.
#p3-workflow-readings-spikes-interpretation-0014Can radon spike to dangerous levels in just a few hours?
Yes, radon can move fast in the right conditions. A significant pressure drop ahead of a major storm can push readings from 2 pCi/L to 10+ in a matter of hours. Even so, the health risk from radon isn't about a few hours of high exposure - it's about what you're breathing over months and years. The spikes are real, but the number that drives the health risk calculation is your long-term average, not a single afternoon.
#p3-workflow-readings-spikes-interpretation-0015My radon reads normal all day but spikes at 3am. Is that normal?
Yes, that's a very common pattern. In the early morning hours - roughly 2 to 5am - homes tend to be tightly closed, HVAC systems may be on different cycles, and the stack effect (warm air rising and pulling soil air in from below) often peaks. Wind is also typically calmer at night, which reduces natural pressure balancing. These conditions consistently produce higher radon readings in the early morning hours. Your long-term average accounts for all of those cycles together.
#p3-workflow-readings-spikes-interpretation-0016My radon monitor shows a spike every single morning around 4am and then it comes down. Does that mean there's a crack under the floor?
It probably means your house has normal overnight depressurization, not necessarily a specific crack. The 4am pattern is very typical - tight house, calm outside, stack effect working all night. Even so, if the spikes are consistently very high (above 10 pCi/L) or your long-term average is above 4.0, the source could well be entry points worth addressing. A mitigation system would blunt those nightly spikes even without knowing exactly which crack or gap is responsible.
#p3-workflow-readings-spikes-interpretation-0017I left for vacation for two weeks and when I came back my Airthings average had gone up a lot. What happened?
A closed-up house with no ventilation for two weeks is a perfect setup for radon to accumulate, especially in the basement. With no one opening windows or doors, no regular HVAC cycling from daily use, and potentially different pressure conditions, radon can build up noticeably. The elevated reading makes sense given what the house was doing. Watch what happens to the average over the next few weeks now that you're back and the house is being used normally - it will likely settle back toward your normal range.
#p3-workflow-readings-spikes-interpretation-0018My radon jumped the day after we had a big wind event. I thought wind would lower radon?
Wind is complicated when it comes to radon. High winds can create pressure differentials around your house - on one side of the home there may be positive pressure, and on the other side, negative pressure pulling air in. Depending on how your home is oriented and where your radon entry points are, wind can actually drive radon in rather than push it away. It's counterintuitive but well-documented. What you saw is real.
#p3-workflow-readings-spikes-interpretation-0019My radon shot up to 13 pCi/L and the next day it was 1.8. Is the monitor accurate or is it just randomly guessing?
Consumer radon monitors aren't guessing - they're measuring radon decay products in the air. But hourly and daily readings do have more variability than long-term averages because radon itself fluctuates. The swing from 13 to 1.8 in 24 hours is large but not impossible if conditions changed dramatically (a storm passing, windows opened, HVAC shifted). If you see that kind of range frequently with no obvious explanation, it's worth checking whether the monitor is placed correctly - away from exterior walls, HVAC vents, and off the floor.
#p3-workflow-readings-spikes-interpretation-0020My radon hit 30 pCi/L for one reading and I have never seen it that high. Should I call someone immediately?
One reading at 30 pCi/L is alarming-looking but needs context. Check the time it occurred - if it was during a storm, overnight, or after something changed in the house, it's likely a genuine spike rather than a sensor error. One hour at 30 pCi/L does not represent a health emergency, but it does suggest your home can produce very high radon under certain conditions, and that typically means the long-term average is higher than you'd want it to be. I'd be happy to talk through the full picture with you.
#p3-workflow-readings-spikes-interpretation-0021Is the 24-hour reading or the long-term average more important?
The long-term average is far more important for making decisions. A 24-hour reading is a snapshot - it catches whatever conditions happened to exist in that slice of time. Radon naturally rises and falls with weather, season, and daily cycles. The long-term average - ideally 90 days or more - smooths out all of that noise and gives you a realistic picture of what you're actually breathing over time. The 24-hour number is useful for spotting trends and understanding patterns, but don't make a mitigation decision based on a single day.
#p3-workflow-readings-spikes-interpretation-0022What is the difference between a 24-hour reading, 7-day reading, and long-term average?
A 24-hour reading is a single day's snapshot - useful for noticing patterns but heavily influenced by whatever conditions existed that day. The 7-day reading starts to smooth out daily swings and gives a better picture of your weekly norm. The long-term average - which most digital monitors calculate over 30, 60, or 90+ days - is what the EPA and health agencies use as the basis for action decisions. The longer the average, the more reliable it is. For a decision about mitigation, you want at least 90 days of data collected with closed windows and doors.
#p3-workflow-readings-spikes-interpretation-0023My Airthings was 1.5 for 6 months and now it's 4.8. What happened?
A jump like that over time is worth investigating rather than dismissing. A few things could cause it: seasonal change (fall and winter typically drive radon up), a change in how the house is being used (closed up more, basement more finished), or a new source of entry (crack, gap, sump pit opening). It's also possible earlier months averaged low because of open windows in summer. Check whether the timing of the change matches a season shift. If you're now consistently above 4.0, that's the threshold where the EPA recommends fixing it.
#p3-workflow-readings-spikes-interpretation-0024My monitor's long-term average just crossed 4.0 pCi/L. What do I do?
The EPA recommends mitigation at 4.0 pCi/L and above - so crossing that line is a reasonable trigger to act. A mitigation system (typically a sub-slab depressurization system) installed by a qualified contractor will almost always bring levels well below 2.0 pCi/L in most homes. You don't need to panic - this isn't an emergency - but it is a good time to move forward. Give us a call and we can walk through what the process looks like for your home.
#p3-workflow-readings-spikes-interpretation-0025How long does it take before a new radon monitor gives me a number I can actually trust?
Most consumer monitors - Airthings, RadonEye, Ecosense - are considered more reliable after about 30 days, and significantly more reliable after 90 days. The early readings can be skewed by the sensor calibrating, by seasonal conditions, or by recent changes to the house. The device manufacturer will usually tell you the same. Don't panic over week-one numbers, but do keep watching. For a formal decision about mitigation, 90 days of data under normal closed-house conditions is the gold standard.
#p3-workflow-readings-spikes-interpretation-0026My first 24 hours of data on my new monitor were really high. Does that early data count?
The first 24 hours are the least reliable data your monitor will ever produce. The sensor is still warming up, and the very first readings are often outliers. Most manufacturers acknowledge this - some devices actually flag early readings as preliminary. Don't include the first day or two in any average you're using to make decisions. Let the monitor run for at least a few weeks before treating the average as meaningful.
#p3-workflow-readings-spikes-interpretation-0027I've had my Airthings running for 3 days and it says 6.2 pCi/L. Should I be making calls?
Three days is not enough data to make a confident decision. The 6.2 reading could be real, or it could reflect the sensor still settling in, a weather event, or early variability. Let it run for 30 days at minimum - 90 days is better. If after 30 days your average is still above 4.0, then yes, it's time to have a conversation about mitigation. The number at day 3 is a data point, not a diagnosis.
#p3-workflow-readings-spikes-interpretation-0028My radon has been between 2.0 and 3.5 for 3 months. What does that mean?
It means you're in the EPA's "consider mitigation" zone - not at the action threshold of 4.0, but above 2.0 where the EPA says the risk is lower but real and worth thinking about. Some homeowners in that range choose to mitigate, especially if they spend a lot of time in the basement, have kids in the home, or have a family history of lung cancer. Others choose to monitor and watch. There's no wrong answer here - it's a risk tolerance decision. Happy to talk through it if it would help.
#p3-workflow-readings-spikes-interpretation-0029My 24-hour reading is 1.2 but my long-term average is 3.8. Which should I trust?
Trust the long-term average. A single low day - maybe you had windows open, maybe weather conditions were favorable - doesn't represent your real exposure. The 3.8 long-term average built up over weeks or months of normal conditions is a much better reflection of what you're actually living with. At 3.8, you're just under the EPA's action threshold, but you're above 2.0 where the EPA says it's worth considering mitigation.
#p3-workflow-readings-spikes-interpretation-0030My short-term average is way higher than my long-term average. Which one should I use?
In this case, the long-term average is still your most reliable number. If you're in winter and the short-term average is running high, that seasonal factor will eventually pull the long-term average upward too. But don't make a decision based only on a week of elevated readings during an unusual weather stretch. Even so, if your short-term average is consistently well above your long-term average and your long-term average is already at or near 4.0, that's a signal worth acting on.
#p3-workflow-readings-spikes-interpretation-0031My 90-day average is 3.9. My husband says we're under 4.0 so we're fine. Is he right?
He's technically correct that you're under the EPA's action threshold of 4.0 pCi/L - but I'd push back a little on "fine." The difference between 3.9 and 4.0 is not meaningful from a health standpoint; those are essentially the same level of risk. The EPA also says levels between 2.0 and 4.0 are worth considering mitigation because the risk is lower but real. At 3.9, you're an inch under a line that was set for practical guidance, not because 4.1 is dangerous and 3.9 is perfectly fine. It's your call - but I wouldn't dismiss it.
#p3-workflow-readings-spikes-interpretation-0032My radon is 3.9. My husband says we're under 4.0 so we're fine. But I'm pregnant. Does that change anything?
The EPA's guidelines don't have a specific pregnancy threshold separate from the general 4.0 pCi/L recommendation, and radon's known risk is long-term lung cancer from cumulative radiation - not an acute pregnancy risk. Even so, it's completely reasonable to want lower levels while pregnant. Many families in the 2.0-4.0 range choose to mitigate, especially when there are kids or other vulnerable family members in the home. If it gives you peace of mind, mitigation at 3.9 is a defensible choice. For specific medical questions, loop in your OB.
#p3-workflow-readings-spikes-interpretation-0033My radon reads 4.1 pCi/L on a 90-day average. Is that bad?
4.1 pCi/L on a 90-day average is the level where the EPA says you should mitigate. It's not an emergency - radon risk is long-term - but 4.1 over years does carry real cumulative lung-cancer risk, and a mitigation system can typically bring it down below 1.0 pCi/L. There's no reason to wait on this one. Mitigation is a straightforward process and the peace of mind is worth it.
#p3-workflow-readings-spikes-interpretation-0034My radon has been at 5.5 pCi/L for over a year. Is that really dangerous?
Living at 5.5 pCi/L for a year is above the EPA's action threshold, and yes - the cumulative lung-cancer risk from that level of long-term exposure is real and meaningful, particularly if you spend significant time in the home. Radon is the second leading cause of lung cancer in the United States. It's not a number to set aside. The good news is that mitigation almost always works very well, and it can bring a home from 5.5 down to below 1.0 pCi/L in most cases. Getting this fixed is the right move.
#p3-workflow-readings-spikes-interpretation-0035My radon is 7.0 pCi/L. How urgent is this?
At 7.0 pCi/L, you're well above the EPA's action level, and the cumulative risk from prolonged exposure is significant. I wouldn't call it a drop-everything-this-afternoon situation, but I also wouldn't drag my feet. Aim to have a qualified contractor in within the next few weeks. The longer you wait, the more cumulative exposure accumulates - especially if you or family members spend time in the lowest levels of the home. This is fixable, and fixed well by most qualified contractors.
#p3-workflow-readings-spikes-interpretation-0036What radon level should I actually be worried about?
The EPA says fix at 4.0 pCi/L and consider it seriously between 2.0 and 4.0. The World Health Organization uses a lower reference level of 2.7 pCi/L. Realistically, the lower your long-term average, the lower your cumulative risk over a lifetime. There's no level that's completely without risk, but below 2.0 pCi/L, the risk is low enough that most health agencies don't recommend intervention. Between 2.0 and 4.0 is a gray zone. Above 4.0 is a clear action zone.
#p3-workflow-readings-spikes-interpretation-0037My radon is 2.2 pCi/L. Should I be worried?
At 2.2 pCi/L, you're in the range where there is some risk - the EPA acknowledges that - but it's below the action threshold. Whether you choose to mitigate is a personal decision based on how much risk you're comfortable with and factors like how much time you spend in the basement and whether anyone in the home has existing lung disease or a history of smoking. Many people at 2.2 choose to monitor and watch; others at that level choose to mitigate for peace of mind. Either choice is reasonable.
#p3-workflow-readings-spikes-interpretation-0038My average went from 1.8 to 3.5 after we replaced old windows. Is that related?
Possibly, yes. New windows that are better sealed reduce natural air infiltration - which is one of the things that dilutes radon in a basement. Older drafty windows essentially ventilate the space passively; tighter new windows eliminate that. It's counterintuitive but common: weatherization and energy efficiency upgrades can sometimes push radon up by reducing the leakage that was keeping it diluted. This is a known effect and a reason why radon monitoring after major home improvements makes sense.
#p3-workflow-readings-spikes-interpretation-0039My radon reading is different every hour. Is that normal?
Yes, that's completely normal. Radon levels in a home fluctuate throughout the day based on temperature, barometric pressure, HVAC cycles, outdoor wind, and whether windows or doors are open. Consumer monitors show you this real-time variability, which can feel alarming when you're used to seeing a single test result. The hourly swings are real - radon really is moving around - but they don't change your health risk picture. Your long-term average is what matters.
#p3-workflow-readings-spikes-interpretation-0040My radon is higher at night than during the day. Why?
This is very common and has a few causes. During the day, the sun heats the house, HVAC systems run more actively, and more windows or doors might be open - all of which dilute or exhaust radon. At night, the house is closed up, the stack effect (warm air rising and pulling air in from below) is more pronounced, and outdoor winds are calmer, so there's less natural pressure equalization. The result is consistently higher radon readings at night and in the early morning hours.
#p3-workflow-readings-spikes-interpretation-0041My radon is higher in winter than summer. Is that normal?
Yes, this is one of the most consistent patterns in radon behavior. In winter, homes are closed up tight - no open windows, better-sealed doors, and the heating system creating upward airflow that draws more soil air in from below. In summer, more natural ventilation keeps levels lower. This is why the EPA recommends testing with windows and doors closed (simulating winter conditions) - that gives you the worst-case average, which is the number relevant for your year-round risk.
#p3-workflow-readings-spikes-interpretation-0042My radon goes up every time there's a storm. What's causing that?
Storms are associated with dropping barometric pressure, and barometric pressure is one of the primary drivers of radon flux from soil into homes. When outdoor pressure drops, the pressure differential between the soil and the interior of your home changes - effectively the house draws in more soil gas, including radon. High-wind conditions can also create negative pressure on certain sides of the home. It's predictable physics, and it's why radon averages measured during stormy periods can be higher than your true long-term norm.
#p3-workflow-readings-spikes-interpretation-0043My radon goes up when it rains. Is that a radon problem or just weather?
Both, really. Rain can temporarily seal the surface soil, reducing the radon's escape path upward and forcing it to flow laterally toward the pressure difference under your home. Rainstorms also typically bring pressure changes. The result is a real radon spike, but it's weather-driven rather than a sign that something new broke. Your long-term average accounts for these rainy-day spikes as part of your overall exposure picture.
#p3-workflow-readings-spikes-interpretation-0044My radon jumped when it rained. Does that mean my basement leaks and that's letting in radon?
A leaky basement and high radon can coexist, but they're not the same problem. Radon typically enters through soil gas - the air in the soil - not through water. A crack that lets in water could also let in radon-laden soil air, but the rain spike you're seeing is more likely to be the pressure and soil-sealing effect described above than water carrying radon in. If your basement also takes on water, that's a separate structural issue worth addressing, but fixing a water leak alone won't reliably fix a radon problem.
#p3-workflow-readings-spikes-interpretation-0045My radon spiked after I ran the whole-house fan. How is that possible?
A whole-house fan is designed to pull air into the house to cool it - which means it creates significant negative pressure inside the home. That negative pressure pulls air in from every available path, including the soil beneath the slab. Running a whole-house fan is one of the most reliable ways to temporarily spike radon in a basement. This is well-documented, and it's one reason mitigation systems and whole-house fans can sometimes interact. It's not a permanent change to your baseline - the reading should come back down once the fan is off.
#p3-workflow-readings-spikes-interpretation-0046My radon dropped after I opened the windows. Does that mean mitigation isn't needed?
Opening windows reduces radon by diluting and exhausting the basement air - that's real and it works temporarily. But you can't keep windows open year-round, especially in the Midwest, and an open-window strategy doesn't address the source. The minute you close up for winter, radon goes right back up. Mitigation fixes the underlying pressure dynamics so radon doesn't enter the house - that's a permanent solution rather than a ventilation workaround. If your readings drop significantly with open windows, that's actually useful data showing the system will respond well to depressurization.
#p3-workflow-readings-spikes-interpretation-0047My radon was 4.5 during winter and dropped to 1.8 in summer with windows open. Should I mitigate?
Your winter number is the one that drives your risk. You spend most of the heating season with the house closed - and your long-term exposure is a blend of winter highs and summer lows. A 4.5 average in winter, measured under real closed-house conditions, meets the EPA's threshold for recommending mitigation. The 1.8 in summer is great but doesn't represent your full-year average. Mitigation would bring both seasons down and remove the need to worry about it.
#p3-workflow-readings-spikes-interpretation-0048My radon went up after we added insulation to the basement. Why?
Better insulation reduces natural air infiltration, which was previously diluting radon. When you seal and insulate the basement - even with good intentions - you can reduce the passive ventilation that was keeping radon from accumulating. It's a well-known side effect of energy efficiency upgrades. The fix is the same either way: a sub-slab depressurization system that actively removes the radon from under the slab before it enters the house.
#p3-workflow-readings-spikes-interpretation-0049My radon went up after we finished the basement. Is that related?
Finishing a basement is one of the most common triggers for discovering a radon problem. When the basement was unfinished, it may have had gaps, vents, or unsealed areas that passively diluted or exhausted air. Finishing the space - adding drywall, flooring, and improved sealing - can reduce natural ventilation and concentrate radon. More importantly, once it's finished and livable, the exposure matters more because people are actually spending time down there.
#p3-workflow-readings-spikes-interpretation-0050My radon dropped after the contractor sealed a crack in my basement floor. Is that real?
It can be. If that crack was a significant entry point for soil gas, sealing it could genuinely reduce radon. Even so, radon enters through multiple pathways - pores in the concrete, floor-wall joints, pipe penetrations - so sealing one crack rarely eliminates the problem entirely. A modest improvement is plausible, but if your baseline was above 4.0, a single sealed crack is unlikely to bring you into a long-term safe range. Watch your average over the next 30-60 days to see how much the improvement holds.
#p3-workflow-readings-spikes-interpretation-0051My radon reading changed after we moved furniture around. Could moving things affect it?
Not in any meaningful way. Moving furniture doesn't change the underlying radon dynamics of the space. The timing of the reading change is more likely coincidence - weather, season, or pressure - than anything the furniture was doing. If the monitor was moved and is now closer to an HVAC vent, a window, or an exterior wall, that could affect the readings. Monitor placement matters; furniture doesn't.
#p3-workflow-readings-spikes-interpretation-0052My radon reading varies wildly depending on where I put the monitor in the basement. Why?
Radon isn't perfectly uniform throughout a space - there can be pockets where air moves differently, where entry points are concentrated, or where HVAC creates mixing effects. A monitor near a floor drain, sump pit, or crack will read differently than one in the middle of the room. The EPA recommends placing monitors at least 20 inches off the floor, away from exterior walls and HVAC vents, in the area where people spend the most time. That placement gives you the most meaningful data for health risk purposes.
#p3-workflow-readings-spikes-interpretation-0053My radon goes up when the furnace kicks on and comes back down when it stops. Is that normal?
Yes, this is a common pattern. Furnaces draw combustion air and create pressure changes in the basement. When a furnace ignites, it can temporarily depressurize the space, drawing in more soil air. Some furnaces are particularly strong at creating this effect. The fix - a mitigation system - works by reversing the pressure dynamic under the slab, so that soil air is pulled away from the house rather than into it, regardless of furnace cycles.
#p3-workflow-readings-spikes-interpretation-0054My radon is different upstairs than in the basement. Which reading counts?
For health risk and EPA guidance purposes, you test and mitigate based on the lowest livable level of your home - which is almost always the basement. That's where radon is highest and where the exposure matters most. The upstairs reading is typically lower because radon dilutes as it rises through the house. If your basement average is above 4.0, that's the driver of your mitigation decision, even if the first floor reads well below that.
#p3-workflow-readings-spikes-interpretation-0055My basement monitor says 3.0 but my first floor monitor says 0.8. Which matters?
Both matter for different reasons, but for the EPA's action threshold and mitigation decisions, your basement number is the controlling one. The 3.0 in the basement is what family members spending time in that space are actually breathing. The 0.8 upstairs is good information - it tells you radon isn't heavily migrating to the living floors - but it doesn't change the fact that the basement exposure is above 2.0 pCi/L.
#p3-workflow-readings-spikes-interpretation-0056Two monitors in the same basement show different readings. Which one is right?
Consumer radon monitors have measurement variability built in - different brands use different detection methods and different averaging algorithms. Two monitors in the same room can reasonably show readings 10-30% apart on any given day and still both be "accurate" within their specs. Averaging the two readings is a reasonable approach. If they're wildly different (one showing 0.5 and the other showing 8.0), one may be malfunctioning or poorly placed.
#p3-workflow-readings-spikes-interpretation-0057My Airthings and my neighbor's Airthings show different readings even though our houses are right next to each other. Why?
Radon varies significantly from house to house on the same street - even on the same lot. It depends on the construction type, the slab condition, the basement finishing, the HVAC setup, and the specific geology directly under each home. Your neighbor being at 1.0 pCi/L doesn't tell you anything about what's happening under your foundation. Radon really is that local.
#p3-workflow-readings-spikes-interpretation-0058My radon reading at 6am is almost always higher than at 6pm. Is there a rule to when radon is highest?
The general pattern is that radon peaks in the early morning hours - typically between 2am and 6am - and is lower in the afternoon. Overnight, the house is closed, the stack effect is active, and natural ventilation from human activity is absent. By afternoon, solar heating, HVAC activity, and the normal air movement of daily life have diluted and exhausted some of the overnight accumulation. It's not a rigid rule, but it's a consistent enough pattern that researchers have documented it across many home types.
#p3-workflow-readings-spikes-interpretation-0059My radon goes way up on weekends. I don't understand that at all.
Think about what changes on weekends. If you're home more, you may be opening and closing doors more - but you might also be cooking more with hoods exhausting air, running exhaust fans, or keeping the basement more active. Alternatively, if weekends mean more people in the basement watching TV with it all closed up, you might be more accurately capturing basement air. Also check whether your weekends match weather pattern changes. Correlation between weekends and high readings is often coincidental rather than causal.
#p3-workflow-readings-spikes-interpretation-0060My radon was fine for two years and now it's creeping up. Did something change in the house or the ground?
Both are possible. In the house: new weatherization, a finished basement, a new sump pump, or a sealed foundation crack (paradoxically forcing radon through other paths) can all push readings up. In the ground: natural soil settling, frost/thaw cycles that open new pathways, and changes in the local water table can shift radon behavior over years. If your long-term average has now crossed 4.0 after being stable, it's worth acting on regardless of why it changed.
#p3-workflow-readings-spikes-interpretation-0061My monitor shows 0.0 pCi/L. Is that possible or is it broken?
It's possible, though uncommon. Some very well-ventilated spaces - particularly above-grade rooms with lots of fresh air exchange - can read close to or at the detection floor of consumer monitors. It's also possible the monitor hasn't accumulated enough data yet, or that it's averaging across a very stable low-radon period. If it's staying at 0.0 for weeks, check that it's powered on properly and placed where it's supposed to be. Some monitors won't display a reading below their minimum detection threshold and will show 0.0 rather than a fractional number.
#p3-workflow-readings-spikes-interpretation-0062My monitor shows 0.3 pCi/L. Is that actually zero?
Not technically, but for practical health purposes it's as low as it gets. The EPA's outdoor air average is about 0.4 pCi/L - so 0.3 pCi/L is essentially outdoor-level radon inside your home. That's an excellent result. Consumer monitors at that range are operating near the edge of their detection capability, but the reading is real and it means radon is not a concern in your home at this time.
#p3-workflow-readings-spikes-interpretation-0063How accurate is the Airthings Wave Plus?
Airthings publishes accuracy specifications for their devices, and the Wave Plus is one of the more capable consumer monitors on the market for long-term tracking. Like all consumer monitors, it's more accurate over longer averaging periods - hourly and daily readings have more uncertainty than 90-day averages. It's a useful tool for tracking trends and making decisions. For a definitive pre-purchase or post-mitigation measurement, a lab-analyzed test kit gives you a more defensible result.
#p3-workflow-readings-spikes-interpretation-0064Is a consumer radon monitor as accurate as a professional test?
Professional charcoal canisters and alpha track detectors sent to a lab have tighter quality control and licensed accuracy. Consumer monitors are generally reliable for trend monitoring and long-term averages, but there's more variability in their readings, especially day-to-day. For a real estate transaction, a licensed short-term or long-term test is the standard. For general home monitoring and trend awareness, a quality consumer device like Airthings or RadonEye is a solid tool.
#p3-workflow-readings-spikes-interpretation-0065My monitor stored data while my phone was away for a month. Is that data accurate?
The monitor itself collects data whether or not your phone is nearby - most devices store readings onboard. When you reconnect your phone, it syncs the historical data. That stored data is just as accurate as real-time data; the Bluetooth connection is only for display, not for measurement. Your readings during that month are valid and should be included in your averages.
#p3-workflow-readings-spikes-interpretation-0066My Airthings showed a spike that looks off the chart on the graph. Is the data corrupted?
A spike that looks like a data artifact - shooting straight up and back down to zero or to an impossibly high number in one reading - can sometimes be a sensor glitch or a data sync issue. Check whether the spike corresponds to a real event (storm, pressure drop, whole-house fan use). If the surrounding readings look normal and the spike is isolated to a single data point that doesn't fit any pattern, contact Airthings support - they can help determine whether it's a real reading or a device anomaly.
#p3-workflow-readings-spikes-interpretation-0067My RadonEye reads much lower than my Airthings. Which one should I trust?
Both are quality devices, but they use different detection methods and calibration standards. Some users have found RadonEye reads lower than Airthings in direct comparisons; others have seen the reverse. Neither is definitively "right" in every case. If you're trying to resolve the discrepancy, run a licensed charcoal canister test alongside them and compare. For the purposes of your own home monitoring, watch the trend on whichever device you trust more - consistency over time matters as much as the absolute number.
#p3-workflow-readings-spikes-interpretation-0068My monitor is brand new and showing 8 pCi/L on day one. Is that real?
It might be, but take day-one readings with caution. Many monitors need a stabilization period - the sensor is new, environmental conditions vary, and the averaging algorithm may not have enough data to produce a reliable number. A high reading on day one is possible (especially if you're in a high-radon home), but don't act on it immediately. Let it run for at least 30 days and watch where the long-term average settles before making any decisions.
#p3-workflow-readings-spikes-interpretation-0069My monitor's battery is low. Does that affect the radon reading?
Most monitors are designed to give reliable readings until the battery actually fails - they aren't known to produce inflated or inaccurate readings due to a low battery. But some devices may reduce their sampling frequency when battery is low, which can affect the accuracy of short-term averages. Replace the battery when prompted, and treat any readings from the low-battery period as potentially less reliable than normal.
#p3-workflow-readings-spikes-interpretation-0070My monitor is near the floor. Should I move it?
Yes. The EPA recommends placing monitors at least 20 inches (about knee height) off the floor, away from exterior walls, away from HVAC vents, and not in closets or dead-air spaces. Radon is heavier than air and concentrates near the floor, so a floor-level reading will typically be higher than what people at standing or seated height are actually breathing. Moving it to table height in the main part of the basement will give you a more representative reading.
#p3-workflow-readings-spikes-interpretation-0071My monitor is right next to my sump pump. Is that okay?
Not ideal. A sump pump pit is one of the highest-radon spots in a basement - it's essentially an opening directly into the soil. A monitor placed right next to the sump pit will read much higher than what the rest of the basement air looks like. Move it to the center of the basement, at least 20 inches off the floor. If you have a sump pit, it should be sealed as part of a mitigation system anyway.
#p3-workflow-readings-spikes-interpretation-0072My monitor is near an HVAC vent. Does that affect the reading?
Yes, significantly. A monitor near a supply vent will be constantly diluted by fresh conditioned air and will read artificially low. A monitor near a return vent may read higher if it's drawing from basement air. Place the monitor in a stable location away from vents, windows, and exterior walls - somewhere that represents typical breathing-zone air in the space.
#p3-workflow-readings-spikes-interpretation-0073My neighbor said her Airthings was wrong and a professional test showed something different. Should I trust my Airthings?
Consumer monitors are useful tools but aren't identical to licensed lab tests. Airthings devices can be off from professional results, especially if they're still in their early averaging period, placed incorrectly, or if conditions during the test were unusual. For any decision that really matters - selling a home, post-mitigation verification, or unusually high readings - use a licensed test kit as your reference. The Airthings is best used as a monitoring and trend tool, not as a definitive measurement device.
#p3-workflow-readings-spikes-interpretation-0074Can my radon monitor detect a gas leak or anything else dangerous?
No. Consumer radon monitors - whether Airthings, RadonEye, or others - measure radon specifically. They don't detect natural gas, carbon monoxide, or other hazardous gases. If you're concerned about those, you need dedicated detectors. Some multi-sensor devices include CO detection alongside radon, but a standalone radon monitor is single-purpose.
#p3-workflow-readings-spikes-interpretation-0075My radon monitor says it detects VOCs too. Does that help me understand radon better?
The VOC sensor on devices like the Airthings Wave Plus monitors air quality broadly - it measures volatile organic compounds like cleaning products, off-gassing from furniture, and mold-related gases. It's useful air quality information, but it has no direct relationship to radon. Radon is a radioactive gas from soil decay; VOCs are chemical compounds from indoor sources. High VOCs don't indicate high radon and vice versa.
#p3-workflow-readings-spikes-interpretation-0076My radon went up after a basement flood. Is that connected?
Flooding and radon are connected in a few ways. Water entering from the floor or walls means those pathways are open - and the same gaps that let water in can also allow soil gas (including radon) in when it's dry. Additionally, a wet basement creates higher humidity, which can affect how radon moves through the space. If your radon went up after a flood, check the pathways the water came through and consider whether those are also radon entry points.
#p3-workflow-readings-spikes-interpretation-0077My radon went up after we added a sump pump. Is that related?
Very likely. Sump pits are open access points to the soil and the sub-slab environment - prime entry zones for radon. If the pit is uncovered or poorly sealed, it's essentially a chimney for soil gas. Many mitigation systems incorporate a sealed sump lid with the mitigation pipe drawing from within it. If your radon increased after the sump pit was installed, sealing the pit is an important part of any mitigation approach.
#p3-workflow-readings-spikes-interpretation-0078My radon jumped after we jackhammered the basement floor to fix a drain. Is that related?
Almost certainly. Jackhammering the floor opened up the sub-slab environment and may have disrupted pathways that were previously sealed over by concrete. Disturbing the slab also stirs soil gas and can temporarily release significant amounts of radon. After any kind of foundation floor work, it's normal to see elevated readings for a period. Let the averages settle over 30-60 days before deciding whether the elevated reading is the new baseline or a temporary post-construction spike.
#p3-workflow-readings-spikes-interpretation-0079My radon went up after we had a new water heater installed.
A new water heater installation can temporarily affect radon in a few ways: the old equipment was removed and reinstalled, which disrupts airflow and potentially jostles seals; a power-vented water heater alters the pressure dynamics in the mechanical room; and if the installation required any concrete or floor work, that could open pathways. If the spike is recent, give it 30 days and watch the trend. If it persists, the new equipment may have changed how the mechanical room is pressurized.
#p3-workflow-readings-spikes-interpretation-0080Our contractor drilled holes in the basement wall to run new electrical. My radon jumped. Is that related?
Possibly. Drilling into the foundation wall or floor creates new pathways for soil gas to enter. Even small holes can matter if they penetrate into the soil-contact zones. If your radon settled back down after the drilling was completed and sealed, it was likely a temporary disturbance. If the new reading is now your baseline, the holes may not have been sealed, and that's worth addressing.
#p3-workflow-readings-spikes-interpretation-0081My radon went up after we installed a bathroom exhaust fan in the basement. Is that connected?
An exhaust fan in the basement can create negative pressure, drawing in more soil air from below. Similar to a whole-house fan, an exhaust fan that's running significantly increases the pressure difference between the interior and the sub-slab environment - which pulls in more radon. Check whether the radon goes up specifically when the fan runs, or whether it's just a baseline shift. If it's concurrent with fan operation, that's your cause.
#p3-workflow-readings-spikes-interpretation-0082My radon increased after we had a crawl space encapsulation done. I expected it to go down. Why did it go up?
Crawl space encapsulation sometimes redirects radon rather than eliminating it. If the encapsulation sealed pathways that were previously exhausting soil gas passively, radon may now be finding its way into the basement through other routes. A well-done encapsulation with active ventilation should reduce radon, but a poorly vented or sealed crawl space can sometimes push radon into adjacent spaces. This is worth discussing with whoever did the encapsulation work.
#p3-workflow-readings-spikes-interpretation-0083My radon went down after we put new flooring over the basement floor. Is that real?
A new floating floor over the concrete can act as an additional barrier and may modestly reduce radon if the slab was a significant entry point. It's not a mitigation solution - radon still gets in through wall-floor joints, pipe penetrations, and other gaps - but a sealed floating floor can make a small measurable difference. If your long-term average is still above 4.0 after the flooring, the flooring hasn't solved the problem.
#p3-workflow-readings-spikes-interpretation-0084My radon jumped after we installed a wood-burning stove in the basement. Is that why?
Yes, this is a documented cause of radon spikes. Wood-burning stoves consume large amounts of air for combustion and create significant negative pressure in the basement. They draw air from every available source - including soil-contact gaps - which can massively increase radon entry. This effect is similar to whole-house fans and some HVAC systems. A mitigation system should account for the combustion appliance when designing the solution.
#p3-workflow-readings-spikes-interpretation-0085My radon went up after we got a dog and started leaving the basement door open more. Could that be the cause?
Counterintuitively, leaving an interior door open (especially to upper floors) can sometimes increase radon in the basement by changing the airflow and stack effect. The stack effect draws warm air upward through the house - when pathways are open between the basement and upper floors, it can increase the pressure difference between the basement and the sub-slab environment, pulling in more soil gas. It's a real effect, though usually a modest one.
#p3-workflow-readings-spikes-interpretation-0086My radon dropped after we got new windows installed. Is that real?
If the new windows improved ventilation pathways or changed how air moves through the basement, a modest reduction is possible. But new windows that are better sealed can sometimes go the other way (as noted earlier). If your readings genuinely trended down and held lower for 30+ days after window installation, that's real data worth noting. Just don't rely on window ventilation as a mitigation strategy - it's unreliable across seasons.
#p3-workflow-readings-spikes-interpretation-0087I tested my house with a charcoal kit and it came back at 0.5 pCi/L. Is that as low as it gets?
That's an excellent result. 0.5 pCi/L is well below any action threshold and close to the outdoor background level. Results like this in a basement are uncommon but not impossible - you may have very low local uranium concentrations in the soil, very good natural ventilation, or both. There's no action needed at that level.
#p3-workflow-readings-spikes-interpretation-0088Is it possible for a house to have zero radon? (Very Low Readings and Zero Questions)
Not technically. Radon is a naturally occurring gas - it's everywhere in trace amounts, and outdoor air typically contains about 0.4 pCi/L. What some homes have is radon at or near outdoor background levels, which is the practical floor. Some monitor manufacturers will display 0.0 below a certain threshold, but it doesn't mean there is literally zero radon.
#p3-workflow-readings-spikes-interpretation-0089My house tested at 1.1 pCi/L. Is that good?
Yes, 1.1 pCi/L is a good result. It's well below the EPA's action level of 4.0 and below the EPA's consideration zone of 2.0. No action is needed. Continue monitoring periodically - radon can change over time as houses age and soil conditions shift - but at 1.1, you're in good shape.
#p3-workflow-readings-spikes-interpretation-0090My new house tested at 0.8 pCi/L. Does that mean I'll never have a radon problem?
It means you don't have a radon problem right now. Radon levels can change as a house ages, as soil conditions shift, as the foundation develops new cracks, or as you make changes to the home (better insulation, new HVAC, finished basement). Testing every two years is a reasonable habit even when your starting level is low.
#p3-workflow-readings-spikes-interpretation-0091My basement has never had radon over 1.5 pCi/L. Do I still need to monitor?
You don't need to monitor obsessively, but it's reasonable to check every couple of years, especially if you make major changes to the home. A reading of 1.5 pCi/L is low and not a concern - but radon can change. A periodic re-test gives you confidence that things haven't shifted.
#p3-workflow-readings-spikes-interpretation-0092My upstairs bedroom tests at 0.4 pCi/L. Is that normal?
Yes. Upper floors of a home typically have radon levels close to or at outdoor background levels. Radon dilutes as it moves up through a house. A 0.4 pCi/L reading upstairs means radon is not migrating significantly from the basement to the upper floors - that's normal and a good finding.
#p3-workflow-readings-spikes-interpretation-0093My radon is 3.9. We're right at the line. What would you do in my situation?
Honestly, I'd mitigate. The difference between 3.9 and 4.1 is not meaningful from a health or risk standpoint - those are essentially the same level. The 4.0 threshold is a guideline, not a biological cliff. At 3.9, you're spending years breathing that level of radon, and a mitigation system will bring it down to under 1.0 in most homes. That's a significant improvement in long-term risk for a one-time installation. It's worth it.
#p3-workflow-readings-spikes-interpretation-0094My radon is 4.0 exactly. What does the EPA say I should do?
The EPA says fix it. Their guidance is to mitigate at 4.0 pCi/L or higher. At exactly 4.0, you're right at the line, and the EPA is clear that action is recommended. This isn't a borderline call - at 4.0, the recommendation is unambiguous.
#p3-workflow-readings-spikes-interpretation-0095How long can I wait before mitigating if my radon is above 4.0?
The EPA doesn't set a hard deadline because radon risk is cumulative - a few more months won't dramatically change your lifetime exposure picture. But there's also no reason to delay. Mitigation systems are installed in a day, they're effective immediately (though your monitor needs 30+ days to re-average), and the sooner you get it done, the sooner you stop accumulating exposure above 4.0. Aim to schedule within the next month or two if your average is confirmed above 4.0.
#p3-workflow-readings-spikes-interpretation-0096My radon is 2.5. The guy at the hardware store said I shouldn't worry until it hits 4. Is he right?
He's roughly in line with EPA guidance - the formal action threshold is 4.0. But the EPA also says that 2.0-4.0 is a range where you should consider mitigation because the risk is lower but real. At 2.5, whether you mitigate is a judgment call based on how risk-averse you are, how much time you spend in the basement, and personal health factors. The hardware store guy isn't wrong, but it's a more nuanced decision than "don't worry."
#p3-workflow-readings-spikes-interpretation-0097My wife wants to mitigate at 3.5 pCi/L. My brother says that's too cautious. Who's right?
Your wife is making a reasonable call. The EPA says consider mitigation between 2.0 and 4.0, and 3.5 is well into that zone. Your brother is right that it's below the formal action threshold, but the threshold isn't a safety warranty - it's a guideline based on cost-benefit analysis across a large population. A homeowner who chooses to mitigate at 3.5 pCi/L is making a sensible, defensible decision.
#p3-workflow-readings-spikes-interpretation-0098My radon is 5.0 and my husband doesn't want to spend the money on mitigation. How do I convince him?
At 5.0 pCi/L, you're above the EPA's action level, and the long-term lung-cancer risk from sustained exposure at that level is real and meaningful. Radon is the second leading cause of lung cancer in the U.S. - behind only cigarette smoking - and it's responsible for roughly 21,000 deaths per year. The cost of mitigation is a one-time investment; the alternative is years of elevated exposure. Those numbers tend to make the conversation easier.
#p3-workflow-readings-spikes-interpretation-0099My doctor said I should lower my radon. My test came back at 3.8. Can you help?
Yes, absolutely. At 3.8 pCi/L, you're below the formal EPA action threshold but squarely in the zone the EPA says is worth considering. If your doctor has flagged it - particularly if there are lung health concerns - that's a very reasonable trigger to move forward. Give us a call and we can walk through what a mitigation system would look like for your home.
#p3-workflow-readings-spikes-interpretation-0100My long-term average is 4.5 pCi/L. What exactly happens if I don't mitigate?
Nothing immediate - radon doesn't cause headaches, fatigue, or acute symptoms. What happens over time is elevated cumulative radiation exposure to the lungs, which increases your long-term risk of lung cancer. The exact probability depends on how long you live in the home, how much time you spend in the basement, whether you smoke (radon and smoking are significantly synergistic), and other factors. At 4.5 pCi/L over decades of exposure, the risk is real and not trivial.
#p3-workflow-readings-spikes-interpretation-0101My radon is 6.0 pCi/L and I've lived here for 10 years. Should I be worried about what I've already been exposed to?
I understand why you're thinking about that. There's no test for past radon exposure, and there's no point in dwelling on what's already happened. What you can do is mitigate now - bringing levels down going forward significantly changes your long-term risk picture. If you have health concerns, talk to your doctor. From a radon standpoint, the best move is to fix it now and reduce future exposure.
#p3-workflow-readings-spikes-interpretation-0102Does radon cause headaches or fatigue? My monitor spiked and now I feel sick.
Radon does not cause acute symptoms like headaches, sore throat, or fatigue. It is a long-term lung-cancer risk from cumulative radiation exposure - typically developing over years or decades of exposure. If you're feeling ill after noticing a high radon reading, the two are almost certainly not connected. Talk to a doctor about the symptoms. But radon itself doesn't produce the immediate physical effects that some people associate with it.
#p3-workflow-readings-spikes-interpretation-0103My neighbor said high radon made her daughter sick. Is that possible?
Radon's known health effect is an increased risk of lung cancer from long-term cumulative exposure to radon decay products. It does not cause acute illness, allergies, headaches, or the kinds of symptoms that a child would notice in the short term. If your neighbor's daughter was sick, it's very unlikely radon was the cause. Radon is dangerous in a slow, cumulative way - not in a way that produces recognizable illness in the short term.
#p3-workflow-readings-spikes-interpretation-0104What is the Airthings app showing me when it says "current" vs "average"?
The "current" reading on Airthings apps is typically a recent short-term measurement - often the last hour or the last day's reading. The "average" is the long-term average the device has calculated since it started running (or since you reset it). For health and decision-making purposes, the long-term average is the number that matters. The "current" reading is useful for spotting patterns and seeing how conditions are changing in real time.
#p3-workflow-readings-spikes-interpretation-0105My Airthings app shows a "trend" arrow. What does that mean?
The trend arrow indicates whether your radon levels have been moving up or down over a recent period - usually the last week or two. An upward arrow doesn't mean your levels are dangerous; it means they're higher recently than they were before. A downward arrow suggests things are improving. The trend is useful context for your long-term average, especially after a seasonal change or a home improvement project.
#p3-workflow-readings-spikes-interpretation-0106Can I use multiple Airthings monitors in the same house and see them all together?
Yes. Airthings devices connect to the same app and you can view all of them on one dashboard. This is useful if you want to monitor the basement and the main floor simultaneously. Each device tracks its own location's readings independently, so you get a complete picture of how radon moves through different levels of your home.
#p3-workflow-readings-spikes-interpretation-0107My Airthings monitor hasn't connected to Wi-Fi in weeks. Are the radon readings still accurate?
Yes. The Airthings monitors store data onboard regardless of Wi-Fi connection. When connectivity is restored, the historical data syncs to the cloud. The radon measurements themselves don't depend on internet connectivity - the device is measuring continuously. You may have a gap in your cloud history, but the average continues to be calculated by the device itself.
#p3-workflow-readings-spikes-interpretation-0108My RadonEye shows a different reading than the Airthings even though they're sitting next to each other. What gives?
RadonEye and Airthings use different detection technologies and averaging windows. RadonEye uses a pulsed ionization chamber and is known for faster response times, while Airthings uses passive diffusion detection with longer averaging. They can produce notably different readings on any given hour or day, but their long-term averages tend to converge more closely. If you're trying to choose which one to trust, compare both against a licensed test kit result.
#p3-workflow-readings-spikes-interpretation-0109How often do I need to replace or recalibrate my consumer radon monitor?
Manufacturers typically recommend recalibration or replacement every 5-10 years, though this varies by device. Airthings, for example, states that their sensors maintain accuracy for several years under normal use. There's no standardized recalibration service for consumer monitors the way there is for professional instruments. If you've had a device for more than 5 years and you're making an important decision based on it, consider running a licensed test kit alongside it to verify the readings.
#p3-workflow-readings-spikes-interpretation-0110My radon monitor fell off the shelf and hit the floor. Is it still accurate?
It might be, but physical shock can affect sensor accuracy on some devices. Check whether the housing is cracked or damaged. Run a licensed test kit alongside it for 30 days after the fall and compare. If the readings are consistent with what you'd expect for your home and the device shows no signs of damage, it's probably still working. When in doubt, contact the manufacturer.
#p3-workflow-readings-spikes-interpretation-0111My Airthings monitor shows "very high" in red. What does that mean on their scale?
Airthings uses a color-coded scale: green (low), yellow (moderate), and red (very high). The specific thresholds vary by model but generally align with EPA guidance - red typically starts around 4.0 pCi/L or higher. A "very high" reading means your long-term average is at or above the level where mitigation is recommended. It's not an alarm or an emergency, but it's a clear signal to act.
#p3-workflow-readings-spikes-interpretation-0112Does radon in Illinois or the Midwest tend to be higher than in other parts of the country?
Yes. The Midwest - including Illinois, Iowa, Minnesota, Wisconsin, and Indiana - has some of the highest average radon levels in the country due to glacial soils and underlying geology rich in uranium and radium. The EPA has mapped zones of radon potential, and much of the Midwest falls in Zone 1 (highest potential). That doesn't mean every house has high radon, but it does mean testing is particularly important in this region.
#p3-workflow-readings-spikes-interpretation-0113My radon is always high in October and November. Does that mean I should test specifically in those months?
The EPA recommends testing during the heating season - fall through early spring - because that represents the worst-case conditions under which you actually live in a closed house. Testing in October or November is ideal. If your average during that period is above 4.0 pCi/L, that's your realistic worst-case exposure level. Mitigation should be based on those conditions, not a summer reading taken with windows open.
#p3-workflow-readings-spikes-interpretation-0114My radon drops every spring when it warms up. Should I just keep the basement cooler to keep radon low?
Temperature can affect radon to some degree, but it's not a reliable control strategy. The reason radon goes down in spring is primarily because windows open, ventilation increases, and the pressure dynamics change - not just because of the temperature itself. Keeping the basement artificially cool wouldn't replicate those effects and wouldn't meaningfully reduce radon. Mitigation addresses the actual entry mechanism.
#p3-workflow-readings-spikes-interpretation-0115My radon went from 1.5 in summer to 5.8 in winter. Is that a big enough seasonal swing to warrant mitigation?
Yes. A long-term average of 5.8 pCi/L during the heating season - when your home is actually closed up and you're spending the most time in it - is above the EPA's action level. Summer readings at 1.5 pCi/L are nice but don't represent your real-world exposure pattern. You live through winter too, and your cumulative exposure is dominated by the winter average. Mitigate based on the winter number.
#p3-workflow-readings-spikes-interpretation-0116My radon is 3.0 in summer and probably higher in winter. How do I account for the seasonal swing in my decisions?
A good rule of thumb: long-term averages taken in winter or under closed-house conditions should be your reference point for decisions. If your summer average is 3.0, you can reasonably expect winter to be 20-50% higher, putting you potentially in the 3.5-4.5 range. Many homeowners in that situation choose to do a winter test specifically to get the worst-case number. If that winter number comes back above 4.0, the decision is clear.
#p3-workflow-readings-spikes-interpretation-0117We rent our house out in summer. The tenants opened all the windows and now my yearly average looks low. Is that misleading?
Yes, somewhat. If the summer period with open windows is pulling your annual average down significantly, that average isn't a realistic representation of what you breathe during the winter months when the house is occupied and closed up. For your own health decision-making, weight the winter readings more heavily. For a tenant in year-round residence, the average across all conditions matters, but seasonal patterns should be understood.
#p3-workflow-readings-spikes-interpretation-0118My radon seems to be lower on sunny days and higher on cloudy days. Is that my imagination?
It's not your imagination - it's consistent with what's known about barometric pressure. Sunny, stable weather is typically associated with higher barometric pressure, which pushes down on the soil and reduces radon outgassing. Cloudy days often precede or accompany lower pressure, which allows more radon to flow. The pattern is real, though not perfectly consistent.
#p3-workflow-readings-spikes-interpretation-0119Does the ground freezing in winter affect radon levels?
Yes. When the surface soil freezes, it can act as a sealed cap - similar to rain sealing the surface - that redirects radon flow downward and laterally toward the foundation. Frozen ground can push more radon toward your sub-slab environment. This is one of the reasons winter radon levels tend to be higher, on top of the closed-house effect.
#p3-workflow-readings-spikes-interpretation-0120We just got mitigation installed. My Airthings still shows 3.8. Did it not work?
Give it time. A mitigation system immediately changes the pressure dynamics under your slab, but your Airthings long-term average built up over months of high readings. That average will take 30-90 days to re-average down as new low readings replace the older high ones. Watch the daily and weekly readings - they should start dropping within days of installation. The long-term average will follow. Don't judge the system's success on the first week.
#p3-workflow-readings-spikes-interpretation-0121My radon went from 6.0 to 0.8 after mitigation. Is that normal?
Yes, that's a typical and excellent result. A well-installed sub-slab depressurization system routinely brings homes from 4-10+ pCi/L down to under 2.0 pCi/L, and often under 1.0 pCi/L. A drop from 6.0 to 0.8 is exactly what the system is designed to do. Continue monitoring to confirm the levels stay low, especially through the first full winter.
#p3-workflow-readings-spikes-interpretation-0122My radon was mitigated last year and now it's creeping back up. Did the system fail?
It's possible, but don't jump to that conclusion first. Check that the system is running - the fan should be on and the U-tube manometer (if installed) should show a differential. Check that no new entry points were opened (new sump pit, cracked floor). Seasonal changes can also affect readings. If the system is clearly running and your readings are back above 4.0, have the contractor come back for a diagnostic check - the system may need adjustment or an additional suction point.
#p3-workflow-readings-spikes-interpretation-0123My radon went from 5.5 to 3.2 after mitigation. Should I be happy with that?
You're in a better place than before, but 3.2 pCi/L is still in the range where the EPA says consider mitigation - and you've already paid for a system. A well-functioning system should typically bring a home well below 2.0 pCi/L. Talk to your contractor about whether the system needs adjustment, an additional suction point, or whether a diagnostic is in order. Don't settle for 3.2 when the goal should be under 2.0.
#p3-workflow-readings-spikes-interpretation-0124My radon is at 4.8 post-mitigation. Is that normal?
That's not an ideal result. Post-mitigation levels above 4.0 mean the system hasn't brought you to the EPA's action level, which is the minimum standard for success. Contact your contractor - most reputable mitigation contractors warranty their work and will come back to diagnose and adjust. Common fixes include adding suction points, increasing fan capacity, or sealing additional entry points.
#p3-workflow-readings-spikes-interpretation-0125My mitigation system fan is running but my radon is still 6.0. What's wrong?
Several things could be happening: the suction point may not be reaching all areas under the slab (a common issue in homes with rubble-fill sub-slabs), there may be entry points the system isn't addressing (sump pit, wall cracks), or the fan may be undersized for the job. Have your contractor come back for a diagnostic. Smoke testing or pressure field extension testing can identify why the system isn't achieving the expected reduction.
#p3-workflow-readings-spikes-interpretation-0126After mitigation, do I still need to monitor radon?
Yes, and most contractors will tell you the same. Mitigation systems can develop issues over time - fans fail, connections loosen, new cracks develop. Keeping a monitor running means you'll know if the system stops working before the problem has been going on for months. An annual check of your monitor's long-term average is a good minimum habit after mitigation.
#p3-workflow-readings-spikes-interpretation-0127Is my radon promised to stay low after mitigation?
No, and any contractor who promises a promised outcome for all time is overselling. Mitigation systems work by maintaining a pressure differential that draws radon away from the house - as long as the fan is running and the system is intact, they're effective. But fans can fail, systems can be damaged, and conditions can change. That's why ongoing monitoring matters. The vast majority of properly installed systems continue to work well for many years.
#p3-workflow-readings-spikes-interpretation-0128My house is under contract and the buyer's test came back at 5.5 pCi/L. My Airthings shows 3.0. Why the discrepancy?
A few possible reasons: the buyer's test was a 48-hour charcoal test, which is more sensitive to short-term conditions than your long-term average. If the test period coincided with low barometric pressure, a storm, or winter conditions, it could read higher than your steady-state average. Conversely, your Airthings long-term average may be pulling down spikes. It's also possible the charcoal test is simply the more accurate reflection of conditions in your home. The buyer's test result is what the contract will be based on, so take it seriously.
#p3-workflow-readings-spikes-interpretation-0129I just bought a house and the previous owner's radon test showed 3.5. Should I run my own test?
Yes, absolutely. The previous test was done at a point in time - possibly under different seasonal conditions, with different residents and ventilation habits, and possibly years ago. Run your own test now that you're in the home and living in it normally. 3.5 pCi/L is below the action threshold but worth knowing for certain with fresh data.
#p3-workflow-readings-spikes-interpretation-0130My real estate agent says a radon reading of 3.9 is fine and won't affect the sale. Is that true?
Legally and contractually, 3.9 pCi/L is under the EPA's formal action threshold of 4.0, so a seller isn't obligated to mitigate. But a buyer who knows about it - and they should, since it must be disclosed - may still factor it into negotiations. The practical difference between 3.9 and 4.1 from a health standpoint is essentially nothing. Whether it affects the sale depends on the buyer and what they're comfortable with.
#p3-workflow-readings-spikes-interpretation-0131My Airthings long-term average has been under 2.0 for a year but during the buyer's 48-hour test it spiked to 4.5. What do I tell the buyer?
Tell them the truth, including both data points. Explain that your Airthings long-term average reflects a full year of data under normal living conditions, and that the 48-hour test caught a period of high readings - possibly weather-related. Share your long-term Airthings data along with the test result. Some buyers will find that reassuring; others will want mitigation regardless. Being transparent protects you legally and builds trust in the transaction.
#p3-workflow-readings-spikes-interpretation-0132A home I'm buying tested at 8.0 pCi/L. The seller wants to credit me instead of mitigating. Is that smart?
A credit is reasonable only if you actually follow through and get the mitigation done. If you take the credit and never address the radon, you're the one living with 8.0 pCi/L. Mitigation should be a condition of the sale or completed before closing - not just a credit that may or may not be used. Make sure the credit is sufficient to cover the actual cost of mitigation, including any diagnostic work.
#p3-workflow-readings-spikes-interpretation-0133Where exactly is the radon coming from in my house?
Radon comes from the natural decay of uranium in the soil and rock beneath your home. As it forms, it moves as a gas through soil pores and enters your home through openings at or below grade - floor cracks, wall-floor joints, pipe penetrations, sump pits, and even directly through porous concrete. It's not coming from your building materials (in most cases) or from your water supply (unless you're on well water, where waterborne radon can be a factor in some cases).
#p3-workflow-readings-spikes-interpretation-0134My house is on a slab. Where would the radon come from?
Slab-on-grade homes get radon the same way crawl space and basement homes do - through the soil contact zone. Radon seeps up through the soil under the slab and enters through cracks in the concrete, pipe penetrations, and the joint between the slab and foundation walls. Slab homes can have high radon, and they're just as mitigatable as homes with basements.
#p3-workflow-readings-spikes-interpretation-0135My crawl space is dirt. Is that a radon risk?
Yes, a dirt-floor crawl space is essentially an open pathway for soil gas - including radon - to enter the home. The soil is directly exposed, and any gap between the crawl space and the living area allows radon to migrate upward. Encapsulating a crawl space and adding active ventilation or sub-membrane depressurization is an effective mitigation approach for these homes.
#p3-workflow-readings-spikes-interpretation-0136Can radon come from my well water?
Yes, in some cases. Well water drawn from underground aquifers in radon-rich geology can contain dissolved radon, which is released into the air when the water is used (showering, running the faucet). This is more common in certain areas with specific geology. If you're on well water and have elevated radon, testing the water is worth adding to your evaluation. Municipal water supplies generally don't contribute meaningful radon because radon degasses during treatment and transport.
#p3-workflow-readings-spikes-interpretation-0137My neighbor has a high-radon house. Does that mean mine is high too?
Not necessarily. Radon varies house by house, even on the same block. Your neighbor's geology, foundation type, sub-slab conditions, and HVAC setup all affect their radon independently of yours. The only way to know your radon level is to test your house. Proximity to a high-radon neighbor is a reason to test, not a reason to assume.
#p3-workflow-readings-spikes-interpretation-0138Can radon come through the walls?
Yes. Radon can enter through cracks in basement walls, the joint between the floor and walls (the cold joint), pipe penetrations through walls, and directly through porous concrete block or stone. Block foundations are particularly permeable because the hollow cores of the blocks can fill with soil gas and transfer it through the wall. A good mitigation system addresses both floor and wall pathways.
#p3-workflow-readings-spikes-interpretation-0139My house has poured concrete walls and a poured concrete slab. I assumed that would keep radon out. Why is it still high?
Poured concrete is denser than block, but it still has cracks, shrinkage gaps, and penetrations. The most common radon entry point in poured-concrete homes is the cold joint - the gap that forms between the floor slab and the wall where they were poured at different times. Poured concrete homes absolutely can have high radon, and they mitigate just as well as any other construction type.
#p3-workflow-readings-spikes-interpretation-0140My Airthings is in my home office which is on the main floor above a crawl space. Should I move it to the crawl space?
Don't put it in the crawl space - that's not a livable area and isn't where health risk is measured. The relevant question is whether radon from the crawl space is migrating into your office. If your office is directly above the crawl space with only subfloor between them, it may be worth testing the office specifically in addition to the most-used lower level. Place the monitor in the space where you spend the most time.
#p3-workflow-readings-spikes-interpretation-0141My house has both a basement and a crawl space. Do I need to test both?
Testing the lowest livable level (your basement) is the priority. If you spend time in the basement, that reading drives your mitigation decision. The crawl space itself isn't occupied, but if there are areas above it where people spend time, you may want to test those spaces too. Radon from an unsealed crawl space can migrate to upper floors.
#p3-workflow-readings-spikes-interpretation-0142I've been tracking my radon for 6 months and the average has barely changed. Is that good?
Stability over six months is generally a good sign that you understand your baseline. If that stable average is under 2.0 pCi/L, you're in good shape and can relax your monitoring frequency. If it's been stable at 3.5 pCi/L for six months, that stability is telling you this is your real baseline - not a temporary spike - and the consideration of mitigation becomes more informed.
#p3-workflow-readings-spikes-interpretation-0143My app shows a graph with radon spikes every Tuesday. That's so specific. Why would that happen?
This is more likely a coincidence than a Tuesday effect, but think about what's different on Tuesdays in your house. Is there a particular cleaning routine that opens windows or runs exhaust fans? Does the HVAC get serviced? Does the weather in your area happen to follow a pattern? If you can identify something that consistently changes on Tuesdays, that's your explanation. Otherwise, it may just be that Tuesday's weather patterns have coincidentally been different.
#p3-workflow-readings-spikes-interpretation-0144My monitor reading was normal, then I ran a diagnostic program on it and now it shows different numbers. Did I reset the average?
Some devices allow you to reset or recalibrate, which would restart the averaging period. If you ran a firmware update or a device reset, check whether the long-term average was preserved or started over. Most Airthings devices preserve historical data through firmware updates but can be reset to factory settings. Check your device's app history to see whether older readings are still there.
#p3-workflow-readings-spikes-interpretation-0145My radon is 4.2 pCi/L but only in one corner of the basement near the sump. Is that a localized problem or a whole-house problem?
If the monitor is near the sump pit, the reading is heavily influenced by the local high-radon environment of an open sump. That's a real reading but not representative of the whole basement. Move the monitor to the center of the basement, away from the sump pit, and see what the average looks like from a more neutral location. The sump pit is still a problem to address - but your whole-home average may be lower than the corner reading suggests.
#p3-workflow-readings-spikes-interpretation-0146My radon spiked when my spouse started working from home and is now in the basement all day. Does more time in the basement increase radon?
More occupancy in the basement doesn't increase radon levels, but it does increase your family's exposure if levels are elevated. More time at 4.0 pCi/L means more cumulative exposure than an hour a day at 4.0 pCi/L. If your spouse is now spending a significant portion of their day in the basement, the risk calculation shifts and mitigation becomes a higher priority even at levels that might have been tolerable when the space was rarely used.
#p3-workflow-readings-spikes-interpretation-0147My radon monitor shows a high reading and I have asthma. Should I be more worried?
Radon's known health risk is lung cancer from long-term cumulative exposure - not an aggravation of asthma or other respiratory conditions in the short term. Even so, anyone with compromised lung health has more reason to keep their air quality as good as possible, and reducing radon is a reasonable part of that. Talk to your doctor about the specific risk picture for your situation. From a radon standpoint, the response is the same as for anyone else: if levels are above 4.0, mitigate.
#p3-workflow-readings-spikes-interpretation-0148My radon monitor is showing a reading but the number keeps changing every time I refresh the app. Is that a bug?
Most consumer monitor apps update readings on an interval - some show hourly readings, others show more frequent updates. If the number changes every time you refresh, you're likely seeing the most recent measurement update. That's normal and expected. Radon levels fluctuate continuously, so a number that changes with each refresh is the monitor doing its job. The long-term average in the app should be much more stable than the current reading.
#p3-workflow-readings-spikes-interpretation-0149I turned off my mitigation fan for a week while I was waiting for a part. My radon jumped to 9 pCi/L. Is my system responsible for keeping it that low normally?
Yes, exactly. The spike to 9 pCi/L when the fan was off confirms that your mitigation system is doing significant work to keep levels low. That's actually reassuring - it means the system is working properly and that when the fan is running, it's effectively controlling the radon source. Get the part replaced and the fan back online, and your levels should return to their post-mitigation baseline within a few days to a week.
#p3-workflow-readings-spikes-interpretation-0150I measured radon in my garage and it's 7 pCi/L. Does that mean the house is also high?
The garage is typically not considered a living space for EPA action purposes, but if your garage is attached and shares air with the house - through an interior door, shared HVAC, or unsealed penetrations - garage radon can migrate into living areas. High garage radon does suggest significant radon potential in the underlying soil. Test inside the home proper, particularly in the basement or lowest livable level, and use that reading for your mitigation decision.
#p3-workflow-readings-spikes-interpretation-0151My radon is always highest when my windows are open on one side of the house but not the other. That seems backwards.
It's not backwards - it's airflow physics. If you're creating a pressure difference by opening windows on one side but not the other, you can create a wind-driven air current through the house. Depending on how that current moves, it can either dilute or concentrate radon in particular zones. Opening windows on both sides more evenly tends to create better cross-ventilation. But again, open windows aren't a solution - they're a temporary and unreliable variable.
#p3-workflow-readings-spikes-interpretation-0152My kids spend a lot of time in a finished basement playroom. Our radon is 3.5. Should I act?
Yes, I would. At 3.5 pCi/L, you're below the formal action threshold, but kids in a basement playroom represent significant cumulative exposure time - probably more time than most adults spend in a basement. Children have more years ahead of them for that cumulative exposure to accumulate, which is exactly the kind of situation where the EPA's "consider mitigation between 2.0 and 4.0" guidance applies strongly. Mitigation at 3.5 when children are regularly in that space is a defensible and reasonable decision.
#p3-workflow-readings-spikes-interpretation-0153My radon test during a power outage came back low. Is that accurate?
A power outage could affect radon readings if it took down your HVAC system, fans, or any mechanicals that normally influence air pressure. In some homes, loss of HVAC actually lets radon levels change in unexpected ways - without the furnace drawing air, the stack effect changes. A reading taken during a power outage is valid data but may not represent your normal conditions. Let your monitor re-average for 30+ days under normal operation before drawing conclusions.
#p3-workflow-readings-spikes-interpretation-0154Can radon detectors go off like smoke detectors?
No. Consumer radon monitors don't have alarm sounds that trigger at a threshold the way smoke detectors do. They display readings on a screen or app and may use color coding to indicate concern levels, but they won't wake you up with an alarm. Some newer smart home integrations allow notification-based alerts when readings exceed a threshold, but there's no audible emergency alert in the traditional smoke-alarm sense.
#p3-workflow-readings-spikes-interpretation-0155My radon is 2.0 exactly. Is that the line between okay and not okay?
There's no hard biological line - radon risk is a gradient, not a cliff. The EPA uses 2.0 pCi/L as the starting point of the "consider mitigation" recommendation because risk at that level, while lower than at 4.0, is still meaningfully elevated compared to levels closer to outdoor background. At 2.0, you're not in the action zone, but you're not at zero risk either. Whether you act on 2.0 pCi/L is a personal decision that depends on your family situation and risk tolerance.
#p3-workflow-readings-spikes-interpretation-0156My radon test came back in the mail at 4.3 pCi/L. How reliable is a mailed charcoal canister test?
Charcoal canister tests analyzed by licensed labs are a reliable and widely accepted method for radon testing. The test itself is sensitive to conditions - placement location, whether windows were closed during the test period, test duration - but when conducted correctly (closed-house conditions, in the lowest livable level, 48-96 hours), the results are considered valid. At 4.3 pCi/L from a properly conducted test, the result is meaningful and the EPA's action recommendation applies.
#p3-workflow-readings-spikes-interpretation-0157I did two charcoal tests at the same time and got different results. Which one is right?
Radon isn't perfectly uniform in a space, and even two canisters placed a few feet apart may collect slightly different samples. A 10-20% difference between two canisters placed at the same time and location is within normal variability. Average the two results - that gives you a better estimate than either one alone. If the difference is dramatic (one shows 1.0 and the other shows 6.0), the placement locations were significantly different, or one of the canisters was compromised.
#p3-workflow-readings-spikes-interpretation-0158My radon test results came back in a format I don't understand. It says "WL" not pCi/L. What does that mean?
WL stands for Working Level - it's an older unit of radon measurement still used in some professional contexts. One Working Level (1 WL) corresponds to approximately 200 pCi/L of radon in equilibrium with its decay products. Most consumer and residential radon testing uses pCi/L, which is the standard unit for EPA guidance. If your result is in WL, multiply by 200 to get the rough pCi/L equivalent - but contact the lab if you're uncertain.
#p3-workflow-readings-spikes-interpretation-0159What does "picocuries per liter" actually mean? Is it radiation?
Yes, pCi/L measures radioactivity - specifically, it tells you how many radioactive decays are happening per liter of air per second from radon and its decay products. A picocurie is one trillionth of a curie, which is a standard unit of radioactivity. The radon itself isn't what causes cancer - it's the decay products (polonium, bismuth, lead) that lodge in lung tissue and emit alpha radiation that damages cells over years of exposure. The number in pCi/L tells you how much of this decay process is happening in the air you're breathing.
#p3-workflow-readings-spikes-interpretation-0160My friend said radon only matters if you smoke. Is that true?
No. Radon causes lung cancer in non-smokers too - it's the leading cause of lung cancer among people who have never smoked. However, the combination of radon exposure and smoking does dramatically multiply the risk. Smokers exposed to elevated radon are at substantially higher risk than either smokers in low-radon homes or non-smokers in high-radon homes. But non-smokers should not dismiss radon as "only a smoker's problem."
#p3-workflow-readings-spikes-interpretation-0161If I stop smoking and fix my radon, do my risks go down?
Yes, substantially. Both smoking cessation and radon mitigation reduce lung cancer risk significantly. The risk doesn't go to zero overnight - past exposure has already occurred - but the cumulative risk going forward drops substantially when you remove the ongoing exposures. Both actions together are among the most impactful things you can do for lung health.
#p3-workflow-readings-spikes-interpretation-0162My radon was 1.8 before we converted the basement from storage to a living space. Now it's 3.5. Why?
The conversion itself may not have changed the underlying radon levels - what changed is that you're now spending time in a space where 3.5 pCi/L exists, and that space may be more sealed than it was when it was a storage area with gaps and vents. The radon reading may also genuinely be higher due to better sealing during the conversion. Either way, the relevant reading is the one in the now-livable space, and 3.5 pCi/L in a space where your family spends significant time is worth discussing.
#p3-workflow-readings-spikes-interpretation-0163Is there a way to test radon without buying a kit or a monitor?
Short-term charcoal test kits are widely available at hardware stores and online for relatively low cost, and many state radon programs offer them free or at reduced cost. You don't need an expensive electronic monitor to get a valid initial radon measurement. The charcoal kit is a perfectly legitimate starting point.
#p3-workflow-readings-spikes-interpretation-0164My state health department sent me a free radon test kit. Is it as good as a paid one?
Yes. State radon programs distribute charcoal canisters from licensed labs that meet the same quality standards as commercial kits. The analysis is done at accredited labs regardless of whether you paid for the kit yourself or received it through a state program. Use it exactly as directed, and the result will be valid.
#p3-workflow-readings-spikes-interpretation-0165I found an old radon test kit in my garage from 10 years ago. Can I still use it?
No. Charcoal canisters have a shelf life - the activated charcoal degrades and the kit may no longer produce accurate results after a few years. Check the expiration date. Most kits are good for 1-2 years from manufacture. An expired kit may give you a result, but it's not reliable. Get a fresh kit.
#p3-workflow-readings-spikes-interpretation-0166What's the most accurate way to test radon in my home?
A long-term alpha track detector run for 90 days or longer in the lowest livable level, under normal living conditions (windows closed in winter, normal HVAC use), analyzed by a licensed lab, is considered one of the most accurate measures of your actual radon exposure. It integrates the full range of seasonal and daily variation rather than catching a snapshot. A 48-hour charcoal test is faster but more sensitive to short-term conditions. For a definitive picture of your risk, a 90-day test is the gold standard.
#p3-workflow-readings-spikes-interpretation-0167How do I know if a radon testing company or contractor is licensed?
In Illinois and most states, radon professionals are required to be licensed through the state or licensed through a national program like NRPP (National Radon Proficiency Program) or NRSB (National Radon Safety Board). Ask any contractor or tester for their license number and verify it with the state. licensed professionals follow established protocols for testing placement, duration, and reporting that produce defensible, accurate results.
#p3-workflow-readings-spikes-interpretation-0168My contractor said my radon is 4.2 but my monitor says 3.8. Should I believe the contractor's test?
Both numbers are close enough that the difference is within normal measurement variability. The contractor likely used a 48-hour short-term test, which can read higher or lower than your long-term monitor average depending on conditions during those 48 hours. Neither reading is necessarily wrong. At 4.2 pCi/L, the EPA's action recommendation applies. At 3.8, you're just under but solidly in the consideration zone. The actionable answer is the same either way.
#p3-workflow-readings-spikes-interpretation-0169I've been monitoring for 8 months and my long-term average is creeping up slowly from 2.5 to 3.8. Should I worry?
A slow upward trend over 8 months is worth paying attention to. It suggests something is changing - the season, the home, or both. If you're approaching 4.0 and the trend hasn't reversed, it's reasonable to start thinking about mitigation before you cross the threshold. At 3.8 with an upward trend, you may already be at or above 4.0 during your highest-exposure winter weeks.
#p3-workflow-readings-spikes-interpretation-0170My husband says radon monitoring is a waste of money and only contractors care about it. Is he right?
He's not right about this one. Radon is a real and documented health risk - the EPA, the Surgeon General, and major health agencies all recommend testing because radon is the second leading cause of lung cancer in the United States. Monitoring is the only way to know what you're actually breathing. The risk is invisible, odorless, and tasteless. A monitor or a test kit is inexpensive relative to the information it provides.
#p3-workflow-readings-spikes-interpretation-0171I'm a builder and I'm trying to understand why two identical homes I built next to each other have very different radon levels. Is that possible?
Yes, very much so. The local geology can vary within a single lot - the specific soil composition, the presence of fractures or permeable zones, and the depth to uranium-bearing rock all affect how much radon is produced and how easily it migrates. Two homes with identical construction can have radon levels that differ by a factor of 5 or more based purely on what's directly under each foundation. This is why radon testing is done per-home, not per-neighborhood.
#p3-workflow-readings-spikes-interpretation-0172My radon monitor has been running for 3 years without any maintenance. Is that okay?
For most consumer monitors, 3 years of continuous operation is within the expected service life, and no routine maintenance is needed beyond keeping the device powered and avoiding physical damage. However, no sensor runs perfectly forever - if your readings start behaving erratically or you're uncertain about accuracy, running a licensed test kit alongside the monitor is a good way to verify it's still performing correctly.
#p3-workflow-readings-spikes-interpretation-0173My radon has been at 5.5 pCi/L for the entire winter. Is that bad enough to move out?
You don't need to move out. Radon at 5.5 pCi/L is above the EPA action level, and the cumulative risk from long-term exposure at that level is real. But the risk is cumulative over years, not a crisis for the next few weeks. Schedule mitigation, get it installed, and watch your levels come down. Moving out is not necessary or proportionate to the situation.
#p3-workflow-readings-spikes-interpretation-0174My radon spiked to 11 and I got a headache that same day. Could the radon have caused it?
No. Radon does not cause headaches, sore throats, fatigue, dizziness, or any acute symptoms. It is a long-term lung-cancer risk from cumulative radiation exposure - typically developing over years or decades. Your headache has a different cause. The coincidence of timing is just that - coincidence. If you're having persistent unexplained symptoms, see your doctor, but radon isn't the explanation.
#p3-workflow-readings-spikes-interpretation-0175I'm 75 years old and just found out my radon is 6.0. Is it too late to bother mitigating?
No, it's not too late. Radon risk is cumulative - every year of exposure matters. Reducing your radon going forward still meaningfully reduces your ongoing risk, even if you've had some years of exposure behind you. There's no age at which the math says "don't bother." Get it fixed and breathe easier, literally.
#p3-workflow-readings-spikes-interpretation-0176My teenage daughter is very worried about our radon level of 4.2. What do I tell her?
Tell her she's right to take it seriously, and that you're going to fix it. Radon at 4.2 pCi/L is above the EPA's action level, mitigation is effective, and the problem is solvable. The risk is real but it's also manageable - and the fact that you know about it and can address it puts you in a much better position than families who don't test at all. Schedule mitigation and show her the monitor coming down afterward. That's a good outcome and a good lesson.
#p3-workflow-readings-spikes-interpretation-0177We just had a baby and now I'm worried about all the radon. Our level is 2.8. What should we do?
At 2.8 pCi/L, you're in the EPA's consideration range - below the action threshold but above 2.0 where the EPA says the risk is worth thinking about. Having a baby in the home is a reasonable factor in that decision - a child who grows up in the house has more cumulative years of exposure ahead than an adult. Many families in your position choose to mitigate for peace of mind. It's a reasonable call, and we're happy to talk through what that would involve.
#p3-workflow-readings-spikes-interpretation-0178We have a dog that sleeps in the basement. Should I worry about the dog being exposed to radon?
It's a thoughtful question. Dogs and other pets can be affected by long-term radon exposure - studies have documented elevated lung cancer rates in dogs in high-radon environments. Even so, the primary reason to address radon is for the health of the people in the home. If your radon levels are above the EPA threshold, fixing it protects everyone in the house - including the dog.
#p3-workflow-readings-spikes-interpretation-0179Does radon affect different people differently? Like, is my kid more at risk than me?
The same radon level represents different risk depending on how much time is spent in the space, how long the person lives there, and whether they smoke. Children do have more years ahead of them in which cumulative exposure can accumulate, which is one reason the "consider mitigation" guidance between 2.0 and 4.0 pCi/L applies more urgently in homes where children are regularly in the basement. There's no known genetic difference in how radon affects different individuals at the cellular level.
#p3-workflow-readings-spikes-interpretation-0180Can I test radon myself or do I need to hire someone?
You can absolutely test yourself. Consumer charcoal canister test kits are widely available at hardware stores and online, come with clear instructions, and are analyzed by licensed labs. The result is valid when the test is conducted correctly. For a real estate transaction or post-mitigation verification, some buyers or states may require a licensed professional to conduct the test - but for general home monitoring, a DIY kit is perfectly legitimate.
#p3-workflow-readings-spikes-interpretation-0181What's the difference between a short-term and long-term radon test kit?
A short-term charcoal canister test runs for 48-96 hours and is good for a quick snapshot, especially for real estate transactions. A long-term alpha track detector runs for 90 days or more and produces a result that reflects seasonal and daily variation - a much more representative picture of your real exposure. For general home health, the long-term test is more informative. For real estate, a 48-hour test is the standard because there isn't time to do a long-term test in a transaction.
#p3-workflow-readings-spikes-interpretation-0182My long-term alpha track test came back at 3.6 pCi/L. My Airthings says 4.1. Which is more accurate?
Both are measurement estimates with some uncertainty. A well-conducted 90-day alpha track test is considered a reliable gold standard because it integrates over the full period and isn't affected by daily fluctuations. The Airthings long-term average is a continuous reading but has its own sensor variability. The gap between 3.6 and 4.1 is within a reasonable range of variability between measurement methods. Either way, you're straddling the 4.0 threshold, and the decision about mitigation is essentially the same.
#p3-workflow-readings-spikes-interpretation-0183My radon jumped after we put weatherstripping on all the doors. Does that make sense?
Yes. Better weatherstripping reduces air infiltration, which means less fresh air diluting the basement. This is the same mechanism as insulation upgrades and new window installations - improved sealing is great for energy efficiency but can modestly increase radon by reducing passive ventilation. The fix for this is not to leave doors drafty; it's to mitigate the source so that tight sealing doesn't create a radon concentration problem.
#p3-workflow-readings-spikes-interpretation-0184My radon reading went down after my HVAC was serviced. Is that connected?
Possibly. HVAC servicing sometimes adjusts airflow, fan speeds, or duct balancing - any of which could change how air is circulating in the basement. Some HVAC configurations create positive pressure in the basement (pushing radon out), while others create negative pressure (drawing radon in). If servicing adjusted that balance, a change in radon readings is plausible. Worth noting and watching whether it holds.
#p3-workflow-readings-spikes-interpretation-0185My radon is 5.0. What's the typical radon level after a mitigation system is installed?
A well-installed sub-slab depressurization system in a home starting at 5.0 pCi/L will typically achieve post-mitigation levels of 0.5 to 1.5 pCi/L in most homes. The result depends on the specific sub-slab conditions, the foundation type, and how many suction points are needed. Most reputable contractors aim to get below 2.0 pCi/L at minimum, and many achieve results under 1.0 pCi/L. If you're staying above 2.0 after a system is installed, the system needs adjustment.
#p3-workflow-readings-spikes-interpretation-0186My radon mitigation pipe is outside and it froze this winter. Did that affect my radon readings?
If the mitigation fan iced over or the pipe was blocked, it could affect system performance and radon readings temporarily. Most well-designed systems are installed so the exhaust outlet is positioned to resist ice accumulation, but it can happen in extreme cold. Check whether the fan is running, listen for normal operation, and if you have a U-tube manometer on the pipe, confirm it's showing normal differential. If in doubt, call your contractor.
#p3-workflow-readings-spikes-interpretation-0187My radon mitigation company said they got my home to 0.4 pCi/L. Is that a great result?
Yes, 0.4 pCi/L is essentially outdoor background level - that's an excellent result. It means the system is very effectively drawing radon away from the sub-slab environment. Keep the fan running and continue monitoring periodically, but a result at 0.4 pCi/L is as good as it gets.
#p3-workflow-readings-spikes-interpretation-0188How do I know if my mitigation fan is still working?
Most mitigation systems include a visual indicator - either a U-tube manometer (a clear tube with liquid that shows a differential when the fan is running) or an audible check (you can hear the fan). Some systems have alarm indicators that signal fan failure. Check your system quarterly. If you can't tell by looking or listening, a radon tester or your installing contractor can verify the system is functioning.
#p3-workflow-readings-spikes-interpretation-0189My radon monitor shows a big spike that started exactly when I installed the mitigation system. Should I be worried?
This can happen temporarily during installation - when the contractor drills through the slab and opens up the sub-slab environment during the installation process, it can cause a temporary spike. This is normal and expected. Once the system is running with the fan on, levels should drop. Let the system run for at least 30 days and watch your averages. If levels are still high after a month, contact the contractor.
#p3-workflow-readings-spikes-interpretation-0190Should I get a new radon test if I bought a used monitor from someone else?
Used monitors may have calibration drift, especially if they weren't stored properly or were used in a high-radon environment for a long time. Before trusting a used monitor for decisions, I'd recommend running a licensed charcoal canister test alongside it for 48 hours and comparing. If the two are reasonably close, the used monitor is probably still working. If they're far apart, don't rely on the used device without getting it checked.
#p3-workflow-readings-spikes-interpretation-0191My monitor shows radon going up when I cook on the stove. Is that possible?
Unlikely. Cooking on a stove doesn't directly produce radon or affect sub-slab pressure in a meaningful way. However, if your range hood is running while you cook, it can create negative pressure in the kitchen - which is connected to the rest of the house. In homes where radon migrates to upper floors, this could theoretically affect readings. More likely, the timing is coincidental. A kitchen stove is not a radon source.
#p3-workflow-readings-spikes-interpretation-0192My radon monitor reads high whenever my dryer is running. Is the dryer pulling in radon?
Yes, this is a real and documented effect. A dryer vented to the outside exhausts a large volume of air, creating negative pressure inside the house. That pressure differential can draw soil gas in through foundation gaps. If you consistently see higher readings when the dryer runs, that's the mechanism. A mitigation system counters this by creating a stronger, competing pressure differential under the slab - so the dryer's suction draws from the house rather than the sub-slab environment.
#p3-workflow-readings-spikes-interpretation-0193Can anything in my house produce radon that isn't from the soil?
Certain building materials - particularly some imported granite countertops, some types of brick, and certain fly-ash concrete - can emit radon, but at very low levels that rarely approach EPA action thresholds. The overwhelming majority of residential radon comes from the soil and sub-slab environment. If you have very high radon in a home with excellent sub-slab sealing, building materials are worth investigating, but this is an uncommon scenario.
#p3-workflow-readings-spikes-interpretation-0194I tested radon in my attic and it was 0.1 pCi/L. Does that tell me anything about the basement?
Attic radon is nearly always at or below outdoor background levels - radon dilutes massively as it rises through a building, and attics typically have good ventilation. The attic reading doesn't predict the basement reading. Test the basement directly; that's the only way to know.
#p3-workflow-readings-spikes-interpretation-0195My radon monitor app stopped showing new readings for a week but then started again. Is the data for that week missing?
Most monitors store readings internally even when not syncing to the app. When connectivity is restored, the device should sync the missing week's data. Check the app's historical graph - if the gap week is now filled in, the data was recovered. If there's a visible gap in the historical data, those readings may be lost, but the monitor's ongoing average may still have incorporated them internally.
#p3-workflow-readings-spikes-interpretation-0196I've read that some areas have naturally zero radon. Is that true?
No area has truly zero radon. All soil contains at least trace amounts of uranium and its decay products, so radon is produced everywhere. Some areas - particularly coastal areas with sandy soils and good ventilation - have very low average radon levels and most homes test below 2.0 pCi/L. But "low average" for an area doesn't mean any individual home is zero. Local geology, foundation type, and home construction matter more than regional averages.
#p3-workflow-readings-spikes-interpretation-0197My radon was high but my home inspector said it wasn't their concern. Is that right?
Home inspectors vary widely in how they approach radon. Some conduct radon tests as part of their service; others don't. The EPA and most state radon programs recommend testing every home, especially at the time of purchase. If your inspector didn't test or didn't mention radon, that's not unusual - but it means you need to take care of it yourself. It's not something to leave as an unknown.
#p3-workflow-readings-spikes-interpretation-0198I got a radon test done by a real estate company and I'm worried they had a conflict of interest since they wanted to sell the house. How do I know the test was done right?
licensed radon testers follow protocols that include placement rules, closed-house conditions, and tamper-evident documentation. If the test was conducted by a state-licensed or NRPP/NRSB-licensed professional and the result is documented on a licensed lab report, the result is defensible. If you have concerns about the test conditions (window left open, wrong placement, shortened duration), you can request documentation of how the test was conducted or run your own independent test.
#p3-workflow-readings-spikes-interpretation-0199Is there a type of home that is most likely to have high radon?
Homes with basements or crawl spaces in direct soil contact, located in high-uranium geology (much of the Midwest), and built without radon-resistant construction features tend to have the highest radon. homes with unfinished, unsealed basement floors and multiple floor-wall gaps are particularly susceptible. Even so, any home - including slab-on-grade - can have elevated radon. The only way to know is to test.
#p3-workflow-readings-spikes-interpretation-0200My builder said the new house has radon-resistant new construction features. Does that mean I don't need to test?
It means radon-resistant features were installed during construction - typically a gravel layer, a plastic sheeting barrier, and a stub of pipe ready for a fan. It's a meaningful head start, but it doesn't warranty low radon. The EPA still recommends testing new homes with RRNC features, because the actual radon outcome depends on local geology and how the features were implemented. Test it and know for certain.
#p3-workflow-readings-spikes-interpretation-0201What exactly does a radon mitigation system do?
A sub-slab depressurization system - the most common type - installs a pipe through the basement floor or into the crawl space, connecting to the soil or sub-slab void beneath the foundation. A fan creates a slight negative pressure below the slab, drawing radon-laden soil gas away from the house and exhausting it outside above the roofline. By reversing the pressure dynamic, radon no longer has a path into the house. The system runs continuously and is powered by a small fan (similar to a bathroom exhaust fan).
#p3-workflow-readings-spikes-interpretation-0202Will my neighbors' radon affect my radon readings?
No. Radon moves through soil and enters homes through their own specific foundation contact points. Your neighbor's radon doesn't cross into your home's air supply. The geology and soil are shared, but each home's radon level is determined by its own construction and entry pathways. Your neighbor's high radon is a useful reminder to test, but their levels don't predict yours.
#p3-workflow-readings-spikes-interpretation-0203I have two kids with asthma. Our radon is 3.2 pCi/L. Should I mitigate?
Radon doesn't cause or worsen asthma - it's a lung-cancer risk, not a respiratory irritant. Even so, with kids in the home spending time in the basement and a reading of 3.2 pCi/L, you're in the EPA's consideration zone. The cumulative exposure question for children is real, and many families in your situation choose to mitigate for peace of mind. Talk to your pediatrician about the specific health context, and feel free to give us a call to discuss the mitigation option.
#p3-workflow-readings-spikes-interpretation-0204My Airthings just updated its firmware and now the readings look different. Did the update change my data?
Firmware updates can sometimes change how Airthings devices calculate and display averages - they occasionally update their algorithms. Airthings generally preserves historical raw data through firmware updates, but the displayed average may shift if the calculation method changed. Check the Airthings support pages for release notes on the update. If you're concerned about accuracy post-update, run a licensed test kit alongside the device to verify.
#p3-workflow-readings-spikes-interpretation-0205I have a monitor upstairs and one downstairs. The downstairs one is 4.5 and the upstairs one is 0.9. Does mitigation fix both?
Mitigation primarily targets the radon source - the sub-slab environment - which is what's driving the 4.5 reading downstairs. When that source is addressed, the radon migrating to the upper floor also drops, so your 0.9 upstairs reading should improve further as well. The basement number drives the system design, and fixing it benefits the whole home.
#p3-workflow-readings-spikes-interpretation-0206My radon monitor is in the mechanical room next to my furnace and water heater. Is that a good spot?
Not ideal. Mechanical rooms can have unusual airflow, combustion appliance effects, and HVAC intake/exhaust effects that don't represent the rest of the basement. Move the monitor to the area of the basement where people actually spend time - a family room, home office, or common area. That reading is the one relevant to your health.
#p3-workflow-readings-spikes-interpretation-0207If I test radon in my basement and it's fine, does that mean my finished basement will also be fine?
Probably, yes - your basement's radon level reflects the conditions in that space. A finished basement in the same space as an unfinished basement will have similar radon levels. What changes with finishing is how much time people spend there, which changes the health risk calculation even if the radon level itself doesn't change.
#p3-workflow-readings-spikes-interpretation-0208My radon is 6.5 pCi/L and I'm trying to decide between mitigation and just monitoring more. Is monitoring an acceptable option?
Monitoring more won't change your radon level - it will just give you more data points confirming what you already know. At 6.5 pCi/L, you're well above the EPA action level, and the recommendation is unambiguous: mitigate. Monitoring is appropriate for homes that need more data to make a decision. At 6.5 pCi/L on a confirmed long-term average, you have the data. The next step is a phone call to schedule mitigation.
#p3-workflow-readings-spikes-interpretation-0209My long-term average just hit 4.0 for the first time. Is there a grace period before I need to act?
There's no regulatory grace period - this isn't a legal compliance situation. The EPA's guidance is a health recommendation, not a law. At 4.0 pCi/L, the guidance says it's time to act, but you can reasonably take a few weeks to find a qualified contractor. What I'd avoid is letting it sit for months while telling yourself you'll get to it. The cumulative exposure keeps adding up while you wait.
#p3-workflow-readings-spikes-interpretation-0210What's the EPA's actual action level for radon, and why 4.0 pCi/L?
The EPA's action level is 4.0 pCi/L. This threshold was established based on cost-benefit analysis - it represents a level at which the risk is significant enough that mitigation is clearly justified and cost-effective for most homeowners. It's not a biological threshold (there's no level that's "safe"), but it's the practical point where the EPA says the benefits of mitigation clearly outweigh the cost. Many other countries and the World Health Organization use lower reference levels (around 2.7 pCi/L), reflecting different policy trade-offs.
#p3-workflow-readings-spikes-interpretation-0211What does "pCi/L" stand for and how does it compare to the rest of the world's radon measurement units?
pCi/L stands for picocuries per liter, the standard radon measurement unit in the United States. Much of the rest of the world uses Becquerels per cubic meter (Bq/m³). One pCi/L equals approximately 37 Bq/m³. The WHO's reference level of 100 Bq/m³ is equivalent to about 2.7 pCi/L. The EPA's action level of 4.0 pCi/L is approximately 148 Bq/m³. Same physics, different units.
#p3-workflow-readings-spikes-interpretation-0212My friend in Canada said her radon limit is lower than mine in the US. Is that true?
Yes. Health Canada's guideline is 200 Bq/m³, which is approximately 5.4 pCi/L - actually higher than the EPA's 4.0 pCi/L in practical terms. The WHO recommends 100 Bq/m³ (about 2.7 pCi/L) as a reference level. The EPA is more conservative than Health Canada's official guideline but less conservative than the WHO. All of these are guidelines based on risk-benefit decisions, not absolute biological thresholds.
#p3-workflow-readings-spikes-interpretation-0213If I have a radon problem now, will my kids who grew up in this house be at higher risk?
Radon risk accumulates from ongoing exposure. If your kids grew up with elevated radon and are no longer living in the home, their past exposure is fixed - there's nothing to do about what already happened. Their ongoing risk from that exposure is part of their long-term lung health picture. If they're concerned, they should discuss it with a doctor. The actionable thing now is to fix the current home so that any children currently living there don't continue to accumulate exposure.
#p3-workflow-readings-spikes-interpretation-0214I've been tracking radon in my home for two years. How do I use that data to make a decision?
Look at the long-term average - two years of data is excellent. Check whether the average has been stable, trending up, or trending down. Note the seasonal pattern: what does winter look like versus summer? The number that drives your decision is the long-term average under real closed-house conditions. If that average, over two years of data, is consistently above 4.0 pCi/L, mitigate. If it's been consistently between 2.0 and 4.0, consider your family situation and risk tolerance. If it's been under 2.0, you're in good shape - keep monitoring periodically.
#p3-workflow-readings-spikes-interpretation-0215Are there any home improvements that reliably reduce radon without a full mitigation system?
Sealing floor cracks, sealing the sump pit, and improving sub-slab ventilation can reduce radon modestly. Some homeowners see meaningful drops from sealing alone. But sealing is rarely a complete solution because radon enters through multiple pathways that are difficult to fully identify and seal. The EPA and most radon professionals don't recommend sealing alone as a substitute for a mitigation system when levels are at or above 4.0 pCi/L. It can be a useful supplement but not a replacement.
#p3-workflow-readings-spikes-interpretation-0216I installed a vapor barrier in my crawl space. My radon went from 4.5 to 2.8. Is that a success?
That's a meaningful improvement, and the vapor barrier clearly helped. At 2.8 pCi/L, you've moved from the action zone to the consideration zone - that's real progress. Whether you stop there or continue to mitigate further depends on your risk tolerance and how much time is spent in the home. Some homeowners are comfortable at 2.8; others want to get further below 2.0. Either position is reasonable.
#p3-workflow-readings-spikes-interpretation-0217My radon spiked during a tornado warning when we had the house sealed tight. Is that connected?
Absolutely connected. Tornado warnings bring rapidly dropping barometric pressure - sometimes the most dramatic pressure drops you'll see all year. A sealed-up house combined with an extreme pressure event is a recipe for a significant radon spike. After the storm passes and pressure normalizes, your reading should return to its prior range. This is not a structural change to your home's radon profile.
#p3-workflow-readings-spikes-interpretation-0218My radon monitor shows "dashes" instead of a reading. What does that mean?
Most radon monitors show dashes during their initial setup period - they're accumulating data before they have enough to display a meaningful reading. Depending on the device, this can last anywhere from a few hours to a couple of days. If your monitor continues showing dashes after a week of operation, check the device manual or contact the manufacturer - it may indicate a sensor issue.
#p3-workflow-readings-spikes-interpretation-0219We live in a split-level home. Where should I put the radon monitor?
In a split-level home, the lowest livable level - the level closest to grade or below-grade - is where the monitor belongs. If one portion of the home is partially below grade (which is common in split-levels), that's your priority location. Check which level has the most soil contact and where radon is most likely to accumulate.
#p3-workflow-readings-spikes-interpretation-0220My radon is 3.5 and my wife is a two-pack-a-day smoker. Does that change the calculus?
Significantly. The combination of smoking and radon exposure is multiplicative, not additive. A smoker at 3.5 pCi/L faces substantially higher lung cancer risk than a non-smoker at the same level. For a household with a heavy smoker, many radon professionals would recommend considering mitigation even below 4.0 pCi/L. Smoking cessation and radon mitigation together represent the most impactful combination of risk reductions available.
#p3-workflow-readings-spikes-interpretation-0221My radon is 4.0 pCi/L and my mom, who is 80, lives in the basement apartment. Does her age matter?
Age itself doesn't dramatically change how radon affects the lung at the cellular level, but a person who spends significant time in a below-grade apartment at 4.0 pCi/L has meaningful cumulative exposure going forward. At 80, her risk from years of future exposure is different than a 40-year-old's, but the recommendation to mitigate at 4.0 pCi/L still applies. Fixing it is the right call regardless of her age.
#p3-workflow-readings-spikes-interpretation-0222I'm a renter and my landlord won't test for radon. What are my options?
You can test yourself - charcoal canister test kits are inexpensive and available online and at hardware stores. The result is valid regardless of who placed the kit. If your test comes back above the EPA action level, check your state's radon laws - some states have tenant protections related to radon, particularly for multi-family buildings. Illinois has radon-related requirements for certain property types. Knowing your level is the first step, and you can get that without your landlord's cooperation.
#p3-workflow-readings-spikes-interpretation-0223Can radon get into my drinking water and hurt me that way?
In some areas, radon can be dissolved in well water and released into the air when the water is used. The inhalation pathway is considered the primary risk - the EPA estimates that waterborne radon contributes to lung cancer risk primarily through the air it releases during showering and other water use, not through ingesting it. Municipal water supplies generally don't have significant waterborne radon because of treatment and distribution. If you're on well water in a high-radon area, testing your water is worth adding.
#p3-workflow-readings-spikes-interpretation-0224My radon monitor is in a guest bedroom that we almost never use. Is that a useful location?
Not particularly. The EPA's guidance is to place monitors in the lowest livable area where people spend the most time. A rarely used guest bedroom - even if it's on a lower level - doesn't represent your actual exposure. Put the monitor in the basement family room, home office, or wherever family members actually spend time. The health risk calculation is based on where you are, not just what the monitor reads.
#p3-workflow-readings-spikes-interpretation-0225What's the best brand of radon monitor in your opinion?
Several brands have good reputations - Airthings, RadonEye, and Ecosense are among the most commonly recommended consumer monitors. For long-term tracking and trend awareness, the Airthings Wave series is popular and well-reviewed. For fast response (useful for seeing real-time effects of changes), some users prefer RadonEye. The "best" brand depends on what you're using it for. For a professional or post-mitigation verification standard, a licensed lab test is still the gold standard regardless of which consumer monitor you use for day-to-day monitoring.
#p3-workflow-readings-spikes-interpretation-0226Why is radon higher in houses than outdoors?
Outdoors, radon disperses rapidly into the atmosphere - there's essentially infinite dilution. Inside a home, radon that enters from the soil accumulates in an enclosed space with limited air exchange. The concentration in a closed basement can be orders of magnitude higher than outdoor levels because the house acts as a collection vessel for soil gas that would otherwise dissipate. This is why homes - particularly basements - need to be specifically tested rather than inferring safety from outdoor levels.
#p3-workflow-readings-spikes-interpretation-0227If I get mitigation, will my homeowner's insurance go down?
Most homeowner's insurance policies don't adjust premiums based on radon mitigation. Radon isn't typically an insured peril. However, some insurers offering environmental coverage or some specialty green home policies may have provisions. Check with your insurer. The primary benefit of mitigation is health, not insurance savings.
#p3-workflow-readings-spikes-interpretation-0228My Airthings gives me a "weekly" reading and a "monthly" reading. Which should I use to make decisions?
The monthly or long-term average is the right reference point for decisions. The weekly reading gives you a sense of recent trends - useful for seeing whether conditions are improving or worsening. But a single high week or single low week can be misleading. Use the longest-running average available to you for any decision about mitigation.
#p3-workflow-readings-spikes-interpretation-0229Is there any way to tell if my house has radon without testing?
No. Radon is colorless, odorless, and tasteless - completely undetectable by human senses. There are no visual signs in the home, no health symptoms that indicate radon exposure in the short term, and no way to infer radon levels from your neighborhood or building type with any reliability. Testing is the only way to know.
#p3-workflow-readings-spikes-interpretation-0230My house tested high for radon, but a friend says radon monitors aren't reliable. Should I get a lab test to confirm?
Your friend raises a legitimate point - consumer monitors have more variability than licensed lab tests. If you're making a significant decision (mitigation investment, real estate transaction, or very high readings), running a licensed charcoal canister test alongside your monitor to confirm is a smart move. If the lab test confirms elevated levels, you have a solid basis for action. If there's a big discrepancy, it's worth understanding why before proceeding.
#p3-workflow-readings-spikes-interpretation-0231My long-term radon average is 4.3 pCi/L and I have a home office in the basement where I work 40 hours a week. Is that a significant exposure?
Yes. Forty hours per week in a space at 4.3 pCi/L represents substantial cumulative exposure compared to someone who spends minimal time in their basement. This is exactly the kind of situation where the risk calculation is more urgent - the EPA's action guidance applies, and the time-weighted exposure for someone working from a basement office is much higher than for someone who only passes through. Mitigation here is clearly warranted.
#p3-workflow-readings-spikes-interpretation-0232What are the signs that I should call a radon professional immediately?
There's no radon emergency that requires a same-day response - radon risk is cumulative, not acute. But you should call a professional promptly if: your long-term average is consistently above 4.0 pCi/L; your post-mitigation levels are not coming down as expected; your mitigation fan appears to have failed; or you're in a real estate transaction with a radon contingency. There's no need to panic, but don't delay when any of these situations apply.
#p3-workflow-readings-spikes-interpretation-0233What questions should I ask a radon mitigation contractor before hiring them?
Ask whether they're licensed in Illinois (the state requires licensing for radon mitigation contractors). Ask for a written estimate with details on what's included. Ask what result they typically achieve in homes similar to yours. Ask what their warranty or callback policy is if levels don't come down adequately. Ask whether they'll provide documentation of the post-mitigation test result. A professional, straightforward contractor will have clear answers to all of these.
#p3-workflow-readings-spikes-interpretation-0234My radon is 8.0 and I've been in the house for 20 years. What do I do now?
Fix it now. Whatever exposure has occurred over 20 years can't be undone, but the best thing you can do going forward is eliminate the ongoing source. Mitigate, get your levels down, and keep monitoring. If you have health concerns about past exposure, that's a conversation for your doctor. The radon professionals can solve the ongoing problem - the past exposure is behind you and worrying about it won't change it. The future exposure is the part you can control.
#p3-workflow-readings-spikes-interpretation-0235My radon monitor is three years old and the reading seems higher than I remember. Could the sensor be drifting high as it ages?
Some sensors do drift over time, though manufacturers typically design for stable performance over several years. If you have a nagging suspicion that your monitor is reading high relative to what you've experienced historically, run a licensed charcoal canister test alongside it for 48 hours and compare. That'll tell you quickly whether the sensor has drifted or whether your radon has genuinely crept upward.
#p3-workflow-readings-spikes-interpretation-0236My radon went from 2.0 to 6.0 after I added spray foam insulation in the rim joists. Is that the cause?
Very likely. Spray foam in the rim joists dramatically reduces air infiltration at the top of the foundation wall - which was previously one of the main paths for fresh outdoor air to dilute basement radon. Sealing those joists is excellent for energy efficiency but can concentrate radon significantly. You've created a tighter envelope and now the radon has fewer escape routes. Mitigation addresses this by dealing with the source, not just the dilution.
#p3-workflow-readings-spikes-interpretation-0237My monitor was off for two weeks while I was waiting for a replacement charger. Does that gap mess up my long-term average?
A two-week gap in monitoring means those two weeks weren't captured in the average. Your long-term average before the gap is still valid data. When you power the monitor back on, it will start accumulating new readings and the new average will build from there. The gap doesn't corrupt the past data - it just means your average will take a bit longer to be representative of the full period.
#p3-workflow-readings-spikes-interpretation-0238I moved my monitor from a shelf to the floor to make room for something. Now it reads higher. Should I move it back?
Yes, move it back. Radon concentrates toward the floor because it's heavier than air. A floor-level reading will consistently read higher than a reading at breathing height (around 20 inches or more off the floor). The EPA recommends placing monitors away from the floor for exactly this reason - you want the reading that represents what the occupants of the space are actually breathing, not the heaviest concentration pooling at ankle level.
#p3-workflow-readings-spikes-interpretation-0239I'm trying to understand my Airthings data export. There are hundreds of hourly readings. What should I look at?
For a decision about mitigation, look at the long-term average displayed in the app - that's the number that's been calculated across all those hours. If you want to dig into the raw data, average the readings from the past 90 days under normal closed-house conditions (exclude weeks with open windows or unusual activity). Also look at the nighttime pattern (typically 2am-6am) to see how high spikes get, and at the overall trend line to see whether levels are stable, rising, or falling.
#p3-workflow-readings-spikes-interpretation-0240My radon went up when I switched my HVAC from heating to cooling mode in the spring. Why?
Switching HVAC modes can change airflow and pressure dynamics in the home. Heating mode typically uses a furnace that pulls combustion air, creating basement depressurization. Cooling mode uses the central air handler, which may create different pressure patterns. It's also possible the change coincided with the windows being kept closed more tightly for air conditioning after a period of spring ventilation. The combination of factors at seasonal transitions can move readings.
#p3-workflow-readings-spikes-interpretation-0241My radon went up the same week we got a lot of construction work done on the street outside. Could road construction cause radon?
Road construction itself doesn't produce radon, but heavy equipment running nearby can create vibrations that slightly affect soil compaction and gas movement. A more likely explanation is that the timing coincided with weather changes, or that dust and debris led you to close windows more than usual. Street-level construction is not a recognized cause of household radon increases.
#p3-workflow-readings-spikes-interpretation-0242My radon monitor reads much higher when I put it in an interior closet. Why?
Closets have very limited air circulation - air doesn't move through them the way it moves through open spaces. Radon accumulates in dead-air pockets, so a closet reading will typically be higher than a reading in the open room. This is why monitor placement matters: put it in the main living area of the space, not in a corner, closet, or tight alcove.
#p3-workflow-readings-spikes-interpretation-0243My long-term average has been exactly 3.1 pCi/L for four months. Does that seem suspiciously consistent?
Not really suspicious - consumer monitors round to one decimal place and averages can settle into a relatively stable range for extended periods, especially in homes with consistent HVAC and ventilation habits. If the readings day to day are still varying (which they should be), the long-term average smoothing them out to 3.1 is just math. An average that's truly stuck at one number with no daily variation might indicate a sensor issue, but an average that's stable at 3.1 across months with normal day-to-day fluctuation is fine.
#p3-workflow-readings-spikes-interpretation-0244My radon monitor gives a reading in whole numbers, not decimals. Is that normal?
Some lower-cost monitors report in whole picocuries per liter, while others report to one or two decimal places. A monitor that reads "3" instead of "3.2" or "3.4" isn't broken - it's just displaying at a lower precision. For the purposes of deciding whether to mitigate, the difference between 3 and 3.4 pCi/L is not significant. If precise tracking matters to you, consider a monitor with decimal precision in its display.
#p3-workflow-readings-spikes-interpretation-0245My radon reading was 0.0 for the first month I owned the monitor and then shot up to 5.0 suddenly. Did something happen in my house?
A jump from 0.0 to 5.0 after a month is a data-quality question before it's a radon question. Check whether: (1) you moved the monitor during that period, (2) a seasonal change occurred, (3) the initial 0.0 readings were during the sensor's calibration period when readings are less reliable. A jump that clean and abrupt from the detection floor to 5.0 is worth validating with a charcoal canister test rather than acting on immediately.
#p3-workflow-readings-spikes-interpretation-0246My radon monitor gives hourly, daily, weekly, and monthly views. The monthly view looks much calmer than the hourly view. Is that normal?
Yes, completely normal. That's what averaging does - it smooths out the peaks and valleys. The hourly data shows you the actual variability of radon in your home (which can be dramatic). The monthly view shows you the central tendency across all those fluctuations. Both are real data - the hourly view shows you the range of what you're exposed to, and the monthly view shows you the overall average level.
#p3-workflow-readings-spikes-interpretation-0247My mother-in-law claims our radon problem is because we live near a granite quarry. Is she right?
Granite can be a source of radon because it contains uranium. Being near a granite quarry doesn't automatically mean your home has higher radon, but it's plausible that the local geology - which may extend under your foundation - has elevated uranium content. Whether that translates to elevated indoor radon depends on your specific foundation and soil conditions. The only way to know is to test. She's not wrong that granite and radon are connected; she just can't conclude anything definitive about your specific house from that observation alone.
#p3-workflow-readings-spikes-interpretation-0248My radon test came back and I don't know if I should trust the company that analyzed it. How do I know it's a legitimate lab?
Radon testing labs should be licensed by a recognized proficiency program - in the U.S., look for EPA-approved proficiency programs or state certification. The lab report should include the lab's name, certification number, and method used. You can verify certification status through your state radon program or the EPA's list of approved proficiency programs. A legitimate result comes with documentation, not just a number on a piece of paper.
#p3-workflow-readings-spikes-interpretation-0249My radon is 3.8 pCi/L in the basement playroom but 0.6 pCi/L in the master bedroom on the second floor. My kids sleep upstairs. Should the basement number still drive mitigation?
Yes. If your kids are regularly playing in the basement - which your question implies - the 3.8 reading is their exposure during that time. The 0.6 upstairs is great, but if they're spending hours a day at 3.8 in the basement, that's the number that drives your health calculation. Where people actually spend time is where the exposure happens, regardless of where they sleep.
#p3-workflow-readings-spikes-interpretation-0250What does it mean when the Airthings app says my radon is in the "green" zone?
Airthings uses a color-coded system: green generally means below 2.7 pCi/L (below the WHO reference level), yellow means 2.7-4.0 pCi/L (the consideration range), and red means above 4.0 pCi/L (the EPA action level). Green doesn't mean zero risk - all radon exposure carries some risk - but it means your level is below the thresholds where most health agencies recommend intervention.
#p3-workflow-readings-spikes-interpretation-0251My radon dropped from 4.8 to 3.1 after I opened a door between the garage and the basement. Is the garage ventilating my radon problem?
Opening an interior door to the garage changes airflow through the connected spaces, and if the garage is better-ventilated than the basement, it can dilute basement air. But relying on a garage-to-basement airflow for radon control is not a real strategy - garages can also have their own air quality issues (car exhaust, chemicals), and you can't leave that door open year-round safely or practically. Fix the source with a proper mitigation system.
#p3-workflow-readings-spikes-interpretation-0252My radon is high but my carbon monoxide detector never goes off. Are radon and CO the same thing?
No, they are entirely different. Carbon monoxide is a combustion byproduct - produced by burning fuel in furnaces, water heaters, cars, and gas appliances. Radon is a radioactive gas produced by uranium decay in soil and rock. They have different sources, different health effects, and require different detectors. A CO alarm tells you nothing about radon, and a radon monitor tells you nothing about CO. You need separate devices for each.
#p3-workflow-readings-spikes-interpretation-0253My radon has been stable at 5.0 for six months and my contractor says my home would be easy to mitigate. What does "easy to mitigate" mean?
"Easy to mitigate" typically means your home has characteristics that make a standard sub-slab depressurization system straightforward to install and likely to be effective: a relatively intact slab, good sub-slab communication (the gravel or soil beneath the slab allows good airflow), identifiable entry points, and accessible locations for pipe routing and fan placement. Homes with complicated foundations, multiple sub-slab sections, or unusual construction require more diagnostic work and sometimes more suction points. If your contractor is confident, that's a good sign.
#p3-workflow-readings-spikes-interpretation-0254My radon test was done during a period when we were renovating the basement. Could the renovation have skewed the result?
Potentially, yes. Renovation activity - demolition, new openings, changed airflow, workers coming and going with doors propped open - can significantly affect radon readings. A test conducted during active renovation may read higher or lower than your actual baseline depending on what was happening. For a valid baseline reading, test under normal living conditions with no major construction activity, closed windows, and normal HVAC operation.
#p3-workflow-readings-spikes-interpretation-0255My radon was 4.6 pCi/L during a 48-hour test done in January. I want to confirm before mitigating. Should I test again?
A 48-hour test in January under closed-house conditions is a valid basis for mitigation. You don't need to re-test before acting - the EPA's guidance applies to appropriately conducted short-term tests. If you want more confidence, a 90-day long-term test would give you a better picture of your annual average, but at 4.6 pCi/L in winter, a re-test under the same conditions is likely to confirm the same range. The result you have is sufficient to move forward.
#p3-workflow-readings-spikes-interpretation-0256My neighbor did a radon test during summer and got 1.5 pCi/L. She says I should test in summer too so my number looks better. Is that the right approach?
No. Testing in summer with open windows gives you a best-case reading that doesn't represent your actual year-round exposure. The EPA recommends testing under closed-house conditions to get a realistic picture of your exposure during the heating season - the time when radon accumulates and when you spend the most time indoors. A summer open-window reading might be low, but it's not an honest picture of what you're living with year-round.
#p3-workflow-readings-spikes-interpretation-0257My Airthings is connected to a smart home system that shows radon on a dashboard. The number on the dashboard is different from the app. Which is right?
The Airthings app is the authoritative source for your device's readings. Third-party smart home integrations (Apple Home, Google Home, SmartThings) pull data from Airthings via API or integration, and there can be lag, rounding differences, or sync gaps that cause discrepancies. For any decision-making, use the Airthings app directly rather than a third-party display.
#p3-workflow-readings-spikes-interpretation-0258My radon is 4.0 but the test was done in summer. What might it be in winter?
A summer closed-house reading of 4.0 pCi/L suggests your winter reading could be noticeably higher - potentially 20-50% above that, depending on your home. That would put winter readings in the 4.8-6.0 pCi/L range as a rough estimate. This is a meaningful data point: if you're at 4.0 in summer, you're likely well above that during the months when you're most exposed. Mitigation is warranted.
#p3-workflow-readings-spikes-interpretation-0259My radon was high before I bought the house and the prior owner had mitigation installed. Now it's creeping back up to 3.5. Is that normal?
It's not unusual for post-mitigation levels to drift upward slightly over years if the system's fan performance has degraded or new entry points have developed. At 3.5, you're approaching but not yet at the action threshold. Have the system inspected - the fan output and suction pressure should be checked, and any new cracks or sump changes should be evaluated. A well-maintained system should continue performing for many years.
#p3-workflow-readings-spikes-interpretation-0260My radon jumped from 2.0 to 4.5 after we had a new boiler installed. Is the boiler the problem?
A new boiler changes the combustion and venting dynamics in the mechanical room. If the new boiler creates more negative pressure in the basement during operation, or if the installation opened up new pathways (pipe penetrations, modified flue connections), radon entry can increase. Have the installer verify that the combustion air supply is properly configured and that no new unsealed penetrations were created. If the boiler is creating depressurization, that's something a mitigation system would address as part of its overall pressure management.
#p3-workflow-readings-spikes-interpretation-0261My radon is 4.0 pCi/L and I've been on the fence for six months about mitigating. What usually makes people finally decide to do it?
In my experience, it's usually one of three things: they start spending more time in the basement (new home office, kids using the space more); they're about to sell and want it off the table; or they just do the math and realize that six months of inaction was six more months of exposure above 4.0 pCi/L. There's no wrong time to decide - but the sooner you act, the sooner you reduce the ongoing exposure. If it would help to just talk through the numbers, give us a call.
#p3-workflow-readings-spikes-interpretation-0262Can I mitigate my own radon without hiring a contractor?
DIY mitigation is technically possible - the materials are not restricted - but it requires understanding of sub-slab pressure dynamics, proper fan sizing, correct pipe routing, and safe exterior exhaust placement (above the roofline and away from windows). A poorly installed DIY system can be ineffective or even make things worse if it pulls conditioned air from the house instead of soil gas. Most state radon programs and the EPA recommend using a licensed contractor. If your state requires a licensed contractor for mitigation, DIY work may not be installation recordted.
#p3-workflow-readings-spikes-interpretation-0263My radon is 2.8 pCi/L and I've been healthy for 30 years in this house. Doesn't that mean the radon hasn't hurt me?
Radon doesn't announce itself. There's no symptom during exposure and no way to know whether radon contributed to any health outcome until and unless lung cancer develops - and even then, it can't be definitively attributed to a single cause. Thirty years of feeling fine doesn't tell you whether radon affected your lung cancer risk. The risk is silent and cumulative. At 2.8 pCi/L, you're in a range where the risk is real but lower than at higher levels - the decision about mitigation is yours to make with that information.
#p3-workflow-readings-spikes-interpretation-0264My radon monitor's history shows a spike every time I bake bread. That can't be right, can it?
It probably is timing coincidence rather than bread being a radon source. The oven fan, if it exhausts air, could create slight negative pressure. Or the timing just happens to line up with a daily pattern that has other causes. Bread baking doesn't produce radon. Check whether the spike corresponds to running an exhaust fan, opening the oven, or whether it's actually happening at the same time of day regardless of whether you're baking.
#p3-workflow-readings-spikes-interpretation-0265I called a mitigation company and they said my sub-slab communication is poor. What does that mean and does it affect the price?
Sub-slab communication refers to how freely air can move through the material beneath your slab when suction is applied. Homes with a gravel layer or sandy soil under the slab have excellent communication - one suction point can draw air from a large area. Homes with compacted clay, fractured rubble, or dense fill may have poor communication, meaning radon can only be drawn from the immediate area around the suction point. Poor communication typically means more suction points are needed, which does affect the scope and cost of the installation. It's a real diagnostic finding, not a sales tactic.
#p3-workflow-readings-spikes-interpretation-0266My Airthings says I've had 14 days of radon above 4.0 in the last 30. What does that mean for my health?
It means your radon is elevated for a meaningful portion of the month. Cumulative exposure is what drives radon health risk - and 14 out of 30 days above 4.0 pCi/L represents significant average exposure even if some days were lower. Your long-term average is the best single number for health decisions, but 14 high-radon days per month is a pattern that calls for mitigation if it's consistent.
#p3-workflow-readings-spikes-interpretation-0267My radon monitor shows "NA" for the last few days. What happened?
"NA" typically means the device didn't have enough data to calculate a reading - possibly due to a power interruption, a sensor timeout, or a connectivity issue affecting data recording. Check that the device is powered and hasn't been reset. If it's been running continuously but showing "NA," check the manufacturer's troubleshooting guide or contact support. This is usually a device or connectivity issue rather than a radon problem.
*Questions or numbers that aren't adding up? Call or text Bill and we can talk through what your specific readings mean for your home and your family.*
#p3-workflow-readings-spikes-interpretation-0268Related Help
Questions are fine too. Call or text Bill, or send your address and contact info, and he will take it from there.
Reviewed by Bill Dahlstrom, Illinois radon mitigation license RNM2018212.