Date Published: 09/20/2006 [Source]
In 1984, a nuclear engineer named Stanley Watras set off the radiation alarms at his office at the Limerick Nuclear Power Plant in Pennsylvania. The source of his contamination was not his workplace, but his home, which was built on a vein of uranium. Readings revealed the level of poisonous radon gas in his home was almost 700 times that of the federal standard - a health-risk equivalent to smoking 135 packs of cigarettes a day.
The Environmental Protection Agency says about 20,000 Americans die of radon-related lung cancer annually. Exposure to the radioactive gas is the second-leading cause of lung cancer, after cigarette smoking and the No. 1 cause of lung cancer in nonsmokers. That means radon exposure kills more people than secondhand smoke.
The risk depends on the concentration of radon gas in your home and the length of time you are exposed. So read on to find out how you can check for this invisible poison and what steps you can take to protect yourself.
Radon is an odorless, tasteless and invisible radioactive gas that is released during the natural radioactive decay of radium. While some radon is present everywhere in soil, rocks and water, particularly high levels occur in regions rich in uranium, granite, shale and phosphate.
Radon is measured in picoCuries per liter, or pCi/L, - the higher the number, the more concentrated and dangerous the gas. Experts say you should fix your house if it has an average concentration of 4 pCi/L or higher.
Studies suggest that about 7 in 1,000 nonsmokers will develop lung cancer after a lifetime of exposure to radon at 4 pCi/L. At 2 pCi/L, that risk drops to 4 in 1,000. The lung cancer rate is about eight to 10 times higher for smokers at the same levels of radon exposure.
The risk is much worse in the rare house with a sky-high radon level. At a lifetime exposure to 20 pCi/L of radon, a smoker has a 26 percent chance of getting lung cancer and a nonsmoker has 3.6 percent chance.
All homes, new or old, are at risk for radon poisoning, as many factors determine exposure levels. The soil under the house, the condition of the foundation and the weather can affect the rate of radon contamination. Radon levels vary throughout the year (highest levels are usually experienced during the winter) and can fluctuate wildly within a day: the longer the test period, the more accurate the exposure results.
Some areas of the country have more radon risk than others. States on the Gulf Coast and eastern seaboard from Georgia to the Middle Atlantic States tend to have low radon levels. A great swath of the country, from Maine through the Great Lakes states, on to the Upper Midwest and down the spine of the Rocky Mountains, has higher radon risk.
The EPA suggests that remedial measures be taken when the average annual radon concentration exceeds 4 pCi/L. The cost of mitigation can vary from a few hundred dollars to thousands, depending on the severity of contamination and the sources of radon leaks.
By HOLDEN LEWIS