Radon "Questions and Misconceptions" Section

Question: Who can do the test?
Answer: The Maine Radon Registration Act says a Maine registered radon tester must conduct the test, unless the owner or occupant conducts it. This is true for radon in water as well. It is illegal for a Realtor or home buyer to do a radon in air or radon in water test. Similarly, if the home is for sale, an independent registered radon tester is required to perform the test.

Question: Does radon really cause lung cancer and how much research has been done that proves it?
Answer: Although some scientists dispute the precise number of deaths due to radon, all major health organizations (like the Centers for Disease Control and Prevention, the American Lung Association and the World Health Organization) agree with estimates that radon causes thousands of preventable lung cancer deaths every year. This is especially true among smokers, since the risk to smokers is much greater than to non-smokers.

Question: Isn't it true that only tight houses, or houses with basements, have radon problems?
Answer: All types of houses can have radon problems-old homes, new homes, drafty homes, insulated homes, homes with basements and homes without basements. Construction materials and the way the home has been built may also affect radon levels, but this is rare.

Question: Is it true that only houses on ledge have radon problems?
Answer: Houses on all types of surfaces have radon problems. In Maine, the houses with the worst radon problems are on sand and gravel.

Question: I have heard that Radon is only a problem in some parts of Maine, and that where I live, there is no need to worry?
Answer: Radon problems have been found in all parts of Maine. At least 25% of the homes tested in any part of the state have radon problems. It doesn't matter if you're in Kittery or Madawaska, Eastport or Jackman, or anywhere in between. The only way to know your homes' radon level is to test.

Question If a neighbor has radon problems, will I?
Answer: Radon levels vary from home to home. There are many instances of a house with over 100 pCi/L being right next to a house with less than 4 pCi/L. The only way to know if your home has a radon problem is to test it.

Question: If a house had a high radon test, will airing it out before the follow up test will guarantee a low test result?
Answer: Not only may this be a violation of the "short term" testing protocol (a short term of less than 4 days test requires that the house be maintained in "closed house condition" 12 hours prior to the start of the test), but sometimes radon levels actually go up in houses when windows and doors are open, and go back down after they are closed.

Question: I have been told by some people that radon in water is not a problem, that only the radon in air is. Is this true?
Answer: The vast majority of radon related health risk is due to breathing radon. Generally, there are only two places that the radon in your home's air may come from; either from the soil gasses underneath the foundation, or from your home's water supply. The radon easily escapes water when it is agitated or aspirated (shower water, faucet water, dishwashers, washing machines etc) Many Maine homes have high air radon levels due only the radon which escapes from the water. Therefore, the Maine CDC recommends that all homes with wells should test for water radon. Call the radon section (1-800-232-0842) or visit our website for a list of testers and labs that can legally measure radon in water. If your well has high radon levels, the radon section has information on how to fix it. (For more information about the health risks associated with Radon in Water, please refer to the National Academy of Science study: www.epa.gov/OGWDW/radon/nas.html)

Question: If I have air radon problems, will I also have water radon problems and vice versa?
Answer: Sometimes the radon in your home's air comes from the soil gasses, and sometimes it comes from the water (see previous question). Sometimes it comes from BOTH places, but the presence of soil gas radon does not indicate or predict the presence of well water radon (nor does well water radon indicate or predict soil gas radon). Most of the radon in Maine homes comes from the soil gasses.

Question: Is it difficult to sell homes where radon problems have been discovered?
Answer: Our office has found that the reason radon problems cause trouble in real estate transactions, is that it is not discussed candidly, due to the fear of losing a sale. Greater than 50% of our radon calls (on the radon hotline 1-800-232-0842) are real estate related. Where radon problems have been discussed openly and have been fixed, home sales have not been blocked or frustrated. The added protection is usually a good selling point, since a house with low radon today, may indeed have a radon problem in the future.

Question: I bought my home in the summer and the radon level was below the 4 pCi/l action level. Will this level be the same in the winter time?
Answer: Radon levels are typically higher in the winter. Therefore the best time to test and determine if you have a radon problem is during the heating season. Another option is to find your yearly average exposure to radon by doing a long term test, lasting one year. However, because many homes have very high radon concentrations, and also due to need for quicker results when testing for a real estate transaction, a short term test (48 hours to 7 days) is recommended as a first test. A long term test can be considered as a follow up test when the short term result is just above or just below the action level. If the long-term test cannot be performed immediately, it is advisable for you to conduct such a test when you occupy the home. Call the radon section (1-800-232-0842) or visit our website at hp-radon.htm for a list of labs that have met Maine requirements.

Question: The home inspector who performed a radon test for the people interested in buying my home placed the test kit in the basement. The EPA's "Home Buyers and Sellers Guide to Radon" states: "You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations." My basement has a dirt floor and is not a lived in area. Why wasn't the first floor chosen as the test location?
Answer: The EPA documents are excellent general information guides, but do not contain state specific requirements. The State of Maine Radon Air and Water Service Provider Registration Rules state; "...air radon screening tests shall take place in the lowest livable level of the structure, in addition to any other levels requested by the client." In some cases this is made obvious, by the presence of exercise equipment, or a work bench in the basement. Other times it is not as obvious and the trained radon testing professional must use his judgment. If a strong difference in opinion exists on any radon related issue between you and the radon service provider, it is best to call the Radon Section (1-800-232-0842 or 207-287-5698) to resolve the issue.

Radon in Water Maximum Exposure Guideline (MEG) Explained
There has been a great deal of confusion over the question: "At What concentration should I install a radon water mitigation system?" Various states and agencies recommend a wide range for this "action level". The EPA has proposed (for community water supplies only) a "Maximum Contamination Level" (or MCL) of 300 pCi/l, and more achievable "Alternate Maximum Contamination Level"(AMCL) of 4,000 pCi/liter. After much review of all information available, the Maine CDC has decided to adopt 4,000 pCi/l as the MEG for Maine. However, the MEG does not mean you should 'fix' radon in water levels at 4,000 pCi/l. At this concentration, you should look at your risks from all radon sources (soil gas and water), and decide which is most important to reduce. As the radon in water concentration rises above 4,000 pCi/l, it becomes more and more important to consider fixing the radon in water. At around 10,000 pCi/l you should strongly consider fixing the radon in water in addition to any actions you may decide to take regarding radon in air from soil gasses.

Why 4,000 pCi/l? What is a pCi/l?
First of all, what is a pCi/l? A pCi/l ( pico Curie per liter) is a measurement unit of radioactivity per one liter of water. In this case, the radioactivity is due to the presence of Radon gas dissolved in the water.

The 10,000 - 1 Ratio:
Studies have shown for every 10,000 pCi/l of radon in your water, it will add 1 pCi/l to your home's air. Therefore if you have 4,000 pCi/l in your water, it will contribute an average of approximately 0.4 pCi/l of radon to your homes air. This is one-tenth the EPA action level of 4 pCi/l, and is approximately the amount of radon found in outdoor air. According to studies, ingesting water with radon in it does not present a significant health hazard.

For more information, please read the National Academy of Science Study on this issue https://www.epa.gov/OGWDW/radon/nas.html and the Maine Environmental and Occupational Health Programs MEG analysis paper (PDF).

If I have radon in my water, but it is less than 4,000 pCi/l, can I achieve some benefit from the installation of a water radon mitigation system?
The state's radon in water MEG level of 4,000 pCi/l is based on the cost of a mitigation system and consideration of the health risk reduction it will deliver to the occupants of the home. This is also true about the state's radon in air action level of 4 pCi/l. It is the responsibility of each individual to decide for themselves and their family, what health risks they will accept as reasonable. This website was designed with the goal of helping you make this decision for yourself.

We would be pleased to discuss your particular radon situation
and questions with you. If you need to have any of this material clarified,
you may call 1-800-232-0842 (in Maine) or 207-287-5698 (outside Maine)
or email your questions to radon.dhhs@maine.gov.