Testing for Radon

Testing for radon is the only way to know if it is present in your home.

Testing for radon is the only way to know if it is present in your home. There is no requirement in New Hampshire for those professionals testing for radon to be certified but it is recommended to use a nationally certified radon measurement professional especially if a real estate transaction is involved. Nationally certified radon measurement professionals can be found on the following websites:

Types of Testing

There are two different ways to test the air in your home for radon. Short-term testing is a good way to find out quickly what the radon level is in a home. Long-term radon in air testing provides a better year round average result of the radon level. Short-term tests are performed for 2 to 90 days and long-term tests are done for longer than 91 days and up to a year. Short-term testing is often performed with charcoal tests, liquid scintillation test kits, electronic continuous radon monitors, and electret chamber tests. Long-term testing can be performed with alpha track test kits, electronic continuous radon monitors, and electret chamber tests. 

How to Test

You can test for radon in air any time of the year but if you do test during the warmer months, when you are not heating your home and your windows may be open, it is a good idea to test again during the colder months. Radon tends to be higher during the colder months when homes are heated; this is also when people spend more time indoors.

When testing for radon in air it is important to follow these guidelines:

  • Read and follow the test kit instructions very carefully.
  • For short-term testing, close all the windows in the home for 12 hours before and during the test.
  • Opening doors to enter and exit your home is ok.
  • Test the lowest lived-in level of the home where the most amount of time is spent.
  • For short-term testing, avoid testing during major storm events, high winds (over 30 mph), heavy snow, or heavy rain.

A short-term radon test is often performed for real estate sales as this is the quickest way to test for radon and home sales and purchases happen quickly. When doing a radon test for real estate transactions, two-test kits should be used next to each other (at least 4 inches apart) and then an average is taken for the two results. If one of the two tests reads much higher or lower than the other then there is probably an issue with the test kit and testing should be performed again.

As radon levels change on a daily and monthly basis long term radon testing provides a better average, radon level and homes do not need to be closed before or during the testing. Long-term test kits include alpha track, electret chamber, and electronic continuous radon monitors.

Radon in Water Testing

If a home has a private well, testing the water for radon is recommended. Although the health risk from radon in water is much lower than radon in air, some wells in New Hampshire have very high levels of radon in water that have the health risk of lung cancer from the radon that is released from the water into the air. There is also a risk of stomach cancer from drinking water with high radon levels although it is much lower. The New Hampshire Public Health Laboratories in Concord performs radon in water testing and test containers can be ordered through the Public Health Laboratories.