Radon Levels
Radon level of 30 pCi/L: can it be fixed?
Try it
Move a reading around 30 pCi/L
The reading starts at 30 pCi/L. Slide it to see where EPA's guidance changes and how far this number is from each line.
Read a result for 30 pCi/L
Starts at 30.0 pCi/L, this page's reading
EPA’s own thresholds, as its guidance states them.
EPA’s reading of 30.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. That is 26.0 pCi/L above EPA's action level, 7.5 times it.
Short answer
A radon level of 30 pCi/L is very high, 7.5 times the action level and above the highest row on EPA's risk chart. Even very high levels can be reduced to acceptable levels, so the steps are a quick second short-term test, then a fix.
Next step: pick the right test for your home. Which test to use
Key takeaways
- 30 pCi/L is 7.5 times EPA's 4 pCi/L action level.
- More than twice the action level: confirm right away, then fix.
- EPA estimates the average U.S. home at about 1.3 pCi/L; 30 pCi/L is 23.08 times that.
- Confirm a first short-term result this high with a second short-term test immediately.
Where it sits
Is a radon level of 30 pCi/L high?
The risk chart stops at 20
- About 1110 Bq/m3
- 30 pCi/L in becquerels per cubic meter, at about 37 Bq/m3 per pCi/L (calculated).
- 7.5 times
- EPA's 4 pCi/L action level (calculated).
- 23.08 times
- The U.S. indoor average of about 1.3 pCi/L (calculated).
Read moreThree paragraphs and a table, 1 min
With a source this strong, design matters. The number and location of suction points depends on how easily air moves under the slab and on the strength of the radon source, and a contractor may run diagnostic tests to design the system.
At about 1,110 Bq/m3, 30 pCi/L is 75 times the outdoor average and 23 times the average U.S. home, by our calculation. To reach 2 pCi/L a system has to remove 93% of the radon, close to the top of the up to 99 percent EPA cites, which is why a contractor may run diagnostic tests before choosing the suction points and fan for a source this strong.
Where 30 pCi/L sits against EPA's and WHO's reference points
Against outdoor air (about 0.4 pCi/L)
75 times the outdoor average (calculated)Against WHO's recommended reference level (100 Bq/m3, 2.7 pCi/L)
Above itEPA's band
More than twice the action level: confirm right away, then fix
Other readings explained: 1 pCi/L, 2 pCi/L, 3 pCi/L, 4 pCi/L, 5 pCi/L, 6 pCi/L, 7 pCi/L, 8 pCi/L, 10 pCi/L, 12 pCi/L, 20 pCi/L, 100 pCi/L.
What to do
What to do about a radon level of 30 pCi/L
EPA recommends fixing a home when the radon level is 4 pCi/L or higher. For a reading of 30 pCi/L, the steps come to this:
Steps for a reading of 30 pCi/L
Retest right away
30 pCi/L is 7.5 times the action level, more than twice it, so take a second short-term test immediately rather than wait for a long-term test.Check the first test
Improper testing may give inaccurate results; confirm the device, its placement and closed-house conditions.Fix the home
EPA recommends fixing a home when the radon level is 4 pCi/L or higher. Get estimates from qualified contractors; see radon mitigation.Test after the fix
No sooner than 24 hours and within 30 days after the system starts, then at least every two years.
Read moreA paragraph, 1 min
The full sequence of tests, from a first result to the decision to fix, is drawn on radon testing.
Health risk
The lung cancer risk at 30 pCi/L
EPA's risk chart stops at 20 pCi/L, so 30 pCi/L is above its highest row. The table shows that top row; the risk at 30 pCi/L is higher.
| Radon level | People who smoked | People who never smoked | What to do |
|---|---|---|---|
| 20 pCi/L (740 Bq/m3) | About 260 in 1,000 | About 36 in 1,000 | Fix your home |
Read moreTwo paragraphs, 1 min
The chart's top row, 20 pCi/L, gives about 260 in 1,000 people who smoked (250 times the risk of drowning), and about 36 in 1,000 who never smoked (35 times the risk of drowning). 30 pCi/L is 1.5 times that row's level (our calculation), so the risk at 30 pCi/L is higher than the top row shows.
These are population estimates from EPA's 2003 assessment, and at 30 pCi/L (about 1,110 Bq/m3) a home is 1.5 times past the chart's last row: the chart gives no figure that high, and fixing the home comes first.
How sure
How certain is a reading of 30 pCi/L?
At 30 pCi/L the question is not whether the home is high but how high, since a day-to-day or seasonal swing cannot explain a reading this far above the
Read moreA note, 1 min
With a system
How much a radon system would lower 30 pCi/L
From 30 pCi/L, an active system at the low end of its typical range would leave about 15 pCi/L, still at or above the action level, so the test after installation decides whether the system is enough; at the high end, about 0.3 pCi/L. Our arithmetic on the published ranges, not a prediction for your house: radon levels in most homes can be reduced to 2 pCi/L or below.
| Technique | Typical reduction | From 30 pCi/L, about |
|---|---|---|
| Active suction: sub-slab, sump hole, drain tile, or a crawl-space membrane | 50 to 99 percent | 15 to 0.3 pCi/L |
| Passive sub-slab suction (no fan) | 30 to 70 percent | 21 to 9 pCi/L |
Read moreA paragraph, 1 min
Which technique fits depends on the foundation; see radon mitigation systems, and for cost, radon mitigation cost.
Situations
Where people meet a reading of 30 pCi/L
30 pCi/L in three common situations
30 pCi/L in a basement
Levels are usually higher in basements and rooms in contact with the ground, though considerable concentrations can also occur above the ground floor. Test the lowest lived-in level.Designing a system for 30 pCi/L
How many suction pipes a system needs depends partly on the strength of the radon source, and the contractor may run diagnostic tests to design it.30 pCi/L in a home sale
The buyer and seller should discuss the timing and costs of radon reduction, and the contract can say when mitigation will be done and who will pay.
Retest
When to retest after 30 pCi/L
30 pCi/L is 7.5 times the action level, above the top of EPA's chart. Take a second
| When | What to do |
|---|---|
| To confirm the first result | Immediately, with a second short-term test |
| After a system is installed | No sooner than 24 hours and within 30 days, with a two- to seven-day test |
| With a system in place | At least every two years |
| After a remodel | In the lowest lived-in area |
Show all 4 rows
Read moreA paragraph, 1 min
The general answer is on how often should I test for radon.
Questions
Radon level of 30 pCi/L: questions
Is 30 pCi/L of radon safe?
No. 30 pCi/L is at or above EPA's 4 pCi/L action level, where EPA recommends fixing the home once the result is confirmed.
Do I need radon mitigation at 30 pCi/L?
Yes, by EPA's guidance, once a long-term test or the average of two short-term tests confirms the level is 4 pCi/L or more; 30 pCi/L is 7.5 times that line.
What is 30 pCi/L in Bq/m3?
It is about 1110 Bq/m3, at about 37 Bq/m3 per pCi/L (our calculation).
Should I buy a house with a radon level of 30 pCi/L?
A high level is fixable: from 30 pCi/L, an active system's typical reduction would leave 15 pCi/L or less. Buyers and sellers should discuss the timing and costs of radon reduction, and the contract can say when mitigation happens and who pays. See should I buy a house with radon.
Is 30 pCi/L in a basement different from upstairs?
Usually the basement reads higher. If 30 pCi/L came from a room upstairs, a basement half again as high would read 45 pCi/L, at or above the action level; a test belongs in the lowest lived-in level.
How long should I wait to retest after 30 pCi/L?
Do not wait: 30 pCi/L is more than twice the action level, and a first short-term result that high calls for a second short-term test immediately.
Is 30 pCi/L unusual?
Readings like it are not unheard of: radon in buildings ranges from 10 Bq/m3 to more than 10,000 Bq/m3, and 30 pCi/L is about 1,110 Bq/m3 (our calculation).