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Radon Air Testing

A brief background on radon

Studies have shown that radon is the second leading of cause of lung cancer, and the leading cause of lung cancer in non-smokers in the United States. With a half-live of only 12 hours, radon-222 eventually decays into radioactive particles that can become trapped within the lung tissues of a person who has inhaled air containing radon. This radiation can damage lung tissue and with enough exposure can lead to lung cancer.

Radon is a naturally-occurring radioactive gas which is a part of the uranium-238 decay chain. Uranium-238 exists in trace amounts within many of the bedrock formations below the United States, and the state of Maine has been shown to be one of the areas most prone to radon accumulation in buildings. As uranium decays, radon gas migrates through soil above bedrock formations and enters the atmosphere. Studies have shown that the average outdoor radon-in-air concentration is 0.4 pCi/L (picocuries per liter) of air. When a well-constructed, energy efficient building is placed over soil that emits radon gas, concentrations within a building interior can reach much higher levels.

The United States Environmental Protection Agency has established an action level of 4.0 pCi/L within a building. That is, action should be taken to remove radon from buildings with a determined level of 4.0 pCi/L or greater. The state of Maine however has reduced this action level to 2.0 pCi/L.

Radon is also found dissolved in ground water. Human skin and digestive tract tissue is much more resistant to the radioactive particles of radon than lung tissue. There is no conclusive information to show that consumption of this water or use of radon-containing water for washing of hands, etc. presents a risk to humans. However, radon off-gasses from water rapidly upon exposure to air, and it has been shown that air radon levels can be increased by off-gassing of radon from water as it flows from a faucet to a drain.

For every 10,000 p/Ci.l of radon in water, 1 pCi/L of radon is contributed to the air. Therefore radon-in-water testing is recommended in conjunction with radon-in-air testing. The state of Maine has developed a maximum exposure guideline (MEG) of 4,000 pCi/L radon in water, but these levels should be considered relative to measured air radon.

Emphasis on radon testing and removal has in the past been primarily focused on residential structures. However, employers are becoming more and more aware of the potential health effect of radon on their employees, and as such the presence of radon in the workplace is now a growing concern. However, there are no established protocols specifically written for commercial buildings.

Criterium-Brown Engineers is licensed by the State of Maine as a provider of testing services for radon in air, and radon in water.