RADON

Testing for Radon
Since radon is tasteless, odorless, and colorless, it can’t be detected with your senses. The only way to know whether your home has elevated radon levels is to test with a device specifically designed to detect radon.

About Radon
Radon is a naturally occurring radioactive gas which comes from radium found in the ground everywhere. This gas collects in buildings and forms radon decay products which mostly attach to dust particles in the air. Inhalation of these radon decay products results in deposition of radiation energy (alpha particles) in surface tissues of the lung. This is the largest source of radiation dose to an average person and radon is a known cause of lung cancer in humans. In keeping with normal radiation safety practices for minimizing all sources of radiation dose, AARST recommends testing of buildings and taking action to reduce radon levels below 4pCi/L.

1. Radon is the Largest Contributor to Radiation Dose -- The average person in the U.S. gets more radiation dose from exposure to indoor radon (radon decay products) than from any other source of natural or man-made radiation according to the National Council on Radiation Protection and Measurements (NCRP 1987). At the average indoor radon concentration in the U.S. of about 1.3pCi/L, the dose from radon decay products is about 100 to 200 mrem/year*. In comparison, radiation from the ground contributes about 28 mrem/yr and radiation from outer space contributes another 27 mrem/yr. Radioactive materials in our bodies give another 40 mrem/yr. The use of radiation in x-rays and cancer therapy, consumer products, and nuclear power adds another 65 mrem/yr to our average dose. The U.S. Nuclear Regulatory Commission limits public exposures to man-made radionuclides to 100 mrem/yr. People in homes with radon at the EPA action level of 4 pCi/L could be receiving 300 to 600 mrem/yr. State and Federal programs for radiation protection should be putting more emphasis on the largest source of radiation exposures, namely radon. The radiation dose from naturally occurring radon decay products should not be addressed differently than man-made sources of radiation exposure.

2. Radon is Known to Cause Lung Cancer in Humans -- Radon is classified as a Class A known human carcinogen according to the World Health Organization's International Agency for Research on Cancer (IARC 1988). This classification is based on the strong evidence of lung cancers in underground miners. Data from 11 studies of radon-exposed underground miners show that about 40% of the 2,700 lung cancer deaths which occurred among 65,000 miners are due to radon according to the National Cancer Institute (NCI 1995). Among never-smokers, 70% of the lung cancer deaths are believed to be due to radon and 39% of the lung cancer deaths in smokers. While there are many differences in radon exposure conditions between mines and homes, it is notable that persons living in homes with radon above the EPA action level of 4pCi/L could accumulate radon exposures similar to underground miners. Miner studies show a consistent linear no-threshold relationship between lung cancer and radon exposure down to radon levels commonly found in homes. Epidemiology studies on residential radon exposures are consistent with expectations based on the linear model. Therefore, the National Cancer Institute indicates that 10% of all lung cancer deaths in the U.S. could be due to indoor radon exposures, 11% of lung cancer deaths in smokers and 30% of lung cancer deaths in never-smokers. When differences between mine and home exposures are taken into account, we find that exposures above 4pCi/L represent substantially greater risks than allowed for any other source of radiation exposure.