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It was a quiet Friday afternoon in the office when the call came from a Texas radon laboratory reporting results from a mail-order test kit. A radon test test was showing 1700 picocuries per liter, as high as in a uranium mine and more than 400 times the EPA “action level” for radon of four picocuries per liter.
The laboratory called the Environmental Protection Agency’s Philadelphia office to find out what to do. EPA asked the laboratory to put us in touch with the person who had conducted the test. Radon is a colorless, odorless gas that occurs naturally as uranium decays within the earth. It has been shown to cause lung cancer.
The tester had purchased the kit at a local hardware store. He was measuring radon in his college’s basement library where professors had offices and students studied. This test recorded the highest radon reading ever measured in a large building. EPA and the state of Pennsylvania’s radon staff quickly dispatched teams to the college, only to learn that the radon was even higher than the first measurement showed, about 2100 picocuries per liter in the basement, and about 200 picocuries per liter upstairs.
Six weeks and $5000 later, the radon measurement in the basement of this building is now below 20, and the upstairs is below four. The cost was a bargain for a 40,000 square foot building. Now comes the hard part. Was anyone harmed by the previous high radon levels? Did anyone get lung cancer - or will they?
The answer depends on whom you ask. There are a few people who will swear that radon is harmless. Some even believe it can improve your health, and they actually pay to sit in a radon mine to relieve arthritis. However, most scientists and medical doctors believe radon causes lung cancer. When high levels of radon were discovered in the college library, it had been 10 years since the health effects of radon had been investigated. In 1988, the National Academy of Sciences had concluded that radon was indeed a health risk, even at low levels.
Early in 1994, a group of 13 scientists gathered to discuss the radon problem. These experts on the medical effects of radiation from respected universities, major teaching hospitals, the National Cancer Institute, and the chemical industry -- gathered as a special team appointed by the National Academy of Sciences. In a report to EPA, the group recommended studying a great deal of new research on the health effects of radon.
For the next three years, the scientists reviewed virtually all of the worldwide research. They found new data on uranium miners that showed evidence of additional lung cancer in miners. There were also several research reports involving lung cancer from radon exposure in homes. While the research on radon exposure in homes was promising, it did not provide absolute scientific proof. This doesn’t mean the research project performed in homes showed no health effects -- it did, but could not be definitively linked to radon.
Finding out the chances of a person getting lung cancer from exposure to radon is like figuring out the odds of winning the lottery. In a way, the National Academy of Sciences Committee was trying to learn the odds by looking at the number of winners and losers. In the mines, there was a high exposure to radon, so as high as 40 percent of some of the more exposed groups of miners got lung cancer. This was very easy to detect because there were enough cancers to calculate the odds in this relatively small group. But in a larger group, of less intense household exposures, it appears that a smaller percentage of people get lung cancer from radon. This supports all the existing data which shows that more radon exposure creates more cancer, and less creates less. However, a much larger group of people -- tens of thousands -- would have to be studied to conclusively measure the cancer- causing effects of radon at typical household levels. Until a study that size is done, what risks do scientists see from household radon exposure? Medical experts who have looked carefully at our expanding knowledge of cancer and its causes, again found that any increase in the level of radon exposure correlates to an increased risk of cancer. Based on the available data, they conclude that low levels of radon are harmful in proportion to the amount of exposure. So if you live in a high radon house, you’re playing the radon lottery. You might win, but you might lose. The more radon in your home, the greater your chance of pulling that losing ticket. Like the college library, radon levels in some homes have been found to be as high as in a uranium mine. If you don’t know the amount of radon in your home, you are betting on a life-or-death lottery with no idea of the odds. But there’s an easy way to find out what the odds are; just measure your house for radon. And unlike the lottery, you can actually change the odds in your favor by lowering the radon level in your house, just as the college did for its students. Radon is easy to test for and relatively inexpensive to vent to the outside, where it dilutes in the air and poses no threat. The Environmental Protection Agency continues to recommend that people test their homes for radon. Apartment units and condominiums below the third floor should also be tested. When buying a home, EPA recommends that the buyer be aware of the radon level before the purchase is completed. New homes in high-radon areas should be built using radon-resistant building techniques. If these recommendations are followed, thousands of cancers due to radon could be avoided. EPA has many free publications about radon. Anyone who would like these materials, or who has questions regarding radon or any other indoor air issue, is urged to call the following numbers: EPA at 1-800-438-2474, or 1-800 SOS RADON, or the EPA, Region III Radon Coordinator at 215-814-2086.
Bill Belanger is a health physicist focusing on radiation health concerns for the United States Environmental Protection Agency, mid-Atlantic region. His phone # is (215) 814-2082.