3.7 pCi/L Radon Results

I have a question and wanted to get some additional feedback on radon results for a client.

My client is asking if there should be any concern with his radon levels of 3.7 pCi/L. He is also an attorney, so I want to make sure that what I tell him is correct. How would you guys respond to this question?

Thanks in advance for any advice.

Kip McCullough
Keystone Property Inspections, LLC

After the initial screening measurement has been taken, follow-up action should be taken according with the following recommendations.

Screening Measurement Recommendation
Radon levels:
pCi/L WL

  •                                             *

*0.0-4.0 0-0.02 *

*4.0-10 0.02-0.05 *

10-100 0.05-0.50

>100 >0.50

You have a relatively low probability of avoidable health risk. Follow-up measurements are probably not needed, but may be made at your discretion.

You should perform long-term measurements as soon as practical.

You should perform short-term follow-up measurements as soon as possible.

You should perform short-term follow up measurements promptly and call PA DEP at 1-800-23RADON

The results of follow-up measurements will enable a homeowner to make a well-informed decision about possible health risk and the need for remedial action. As the decision to remediate often involves spending a significant amount of money, follow-up measurements should be reliable and reproducible estimators of the actual or maximum potential exposure of the occupants.

Follow-up measurements should be performed in at least two locations within the home, preferably on the lowest livable level, the basement and on one other living level. The result from each location should be averaged to obtain an overall average for the living areas of the home.

If the result of the screening measurement is between 4 pCi/L(0.02 WL) and 10 pCi/L(0.05), a long term follow-up measurement to estimate the overall annual average concentration should be made. The occupant should consider using a measurement device, such as an alpha-track detector (ATD) or long- term electron ion chamber (EIC) to estimate the average concentration in the living area. An alternative, but less accurate method for estimating annual average is to use the average of short-term measurements made at particular intervals. The year-long measurement is more reliable for determining long-term exposure, because short-term and seasonal variations will be incorporated into the annual estimate. All measurements made to estimate annual averages, whether 12-month integrated or a series of periodic measurements should be made under normal living conditions rather than “closed house conditions”. The results of the measurements in each living area are averaged to estimate the annual average.

If the result of the screening measurement is between 10 pCi/L (0.05 WL) and 100 pCi/L (0.50 WL), a short-term follow-up measurement should be made as soon as practical. A short-term follow-up measurement will minimize additional exposure while providing reproducible results that can be utilized to estimate average concentration.

NOTE: All screening and follow-up measurements are made in accordance with “Protocols for Radon and Radon Decay Product Measurements in Homes”, EPA 402-R-93-003, June 1993

Direct him to the EPA Website following EPA protocols for follow up…


Typically, I would encourage the same as Joe.

On another note, I was browsing other inspector websites and came across the following. Is the cutoff limit, for remediation, in Canada as high as noted?

**“**Make Your Own Decision About Radon”

"The United States Environmental Protection Agency advises radon testing of your home. Some states require radon testing on all residential real estate transfers. Radon is reputed to cause cancer. Radon scares most of us.

What is radon and what are our choices? Radon is a gas produced from the decomposition of uranium in the earth. Most often radon finds its way to the surface through fissures (cracks in the underground rock layers). Radon invades our basements, crawlspaces, and even our homes. The radon level can change from minute to minute, day to day, week to week and from house to house.

There are many methods of testing for radon (scintillation, charcoal, electronic, etc.). These different methods have varying degrees of accuracy. Some have an acceptable error factor as high as 25%. You can purchase radon test kits from many sources (i.e. Internet). It is important to follow the directions closely. You can hire a Home Inspector to perform a radon test. Some use electronic equipment – some use test kits. I have used both. The EPA accepts results from both.

Different countries have different cut off limits for remediation (fixing the problem, i.e. lowering the radon level). In the United States the level is 4 pCi/L (picocuries per liter) of air whereas in Canada the level is nearly 21 pCi/L. Some countries are even higher.

One of the most unusual schools of thought is that radon is actually good for you. There are places such as “radon caves” where individuals go, just to sit in a radon filled environment for the health benefits. I read an argument by one doctor from the far east that actually claimed some exposure to radiation helps prevent cancer ( similar to tanning rather than burning when exposed to the sun).

The bottom line is decide for yourself if you want a radon test and what method of testing you prefer."

Kip is in Georgia (USA).

I would not deviate from the EPA protocol for recommendations with regard to reporting.

Yes, I am not recommending anything to Kip in Georgia…I am curious about the differences stated in my previous post.

Thanks for the great feedback! I appreciate the help.


At 3.7 pico curies p/litre the radon level is in the acceptable range at "the time and dates of your screening".

Mr. Buyer - What it will do next month, next fall, next winter - is anybodys guess. If you need further information go to EPA’s site. Wheres my check?

Nick just posted this in the IAQ2 Forum
Check with your local Government.


Marcel :slight_smile:

My 2 cents.

3.7 pCi/L is acceptable. I would also recommend to them a long term test (greater than 90 days). Long term tests provide a better “average” Radon level.