CR3 News Magazine 2021 VOL 1: JANUARY -- NATIONAL RADON ACTION MONTH | Page 39

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. can not facilitate such as test, but 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 [email protected].

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