Aug 3, 2013

Why is radon a hazard?

Radon is a colorless, odorless, tasteless, radioactive gaseous element produced by the radioactive decay of radium. Its three naturally occurring isotopes are found in many natural materials, such as soil, rocks, well water, and building materials. Because the gas is continually released into the air, it makes up the largest source of radiation that, humans encounter. Some believe that radon may be a significant cause of cancer, especially lung cancer. It has been estimated that radon may cause as much as l0%, or 5,000 to 20,000 cases, of lung cancer deaths annually. Smokers seem to be at a higher risk than nonsmokers. The Environmental Protection Agency (EPA) recommends that the level should not be more than 4 picocuries per liter. The estimated national average is 1.5 picocuries per liter. Because EPA's "safe level" is equivalent to 200 chest x-rays per year, others believe that lower levels should be established. The American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) recommends 2 picocuries/liter. The EPA estimates that nationally 8% to 12% of all houses are above the 4 picocuries/liter; whereas in another survey in 1987, it was estimated that 21% of homes were above this level. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)