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U of M faculty member plays crucial role in designing new World Health Organization radon gas level recommendations

MINNEAPOLIS / ST. PAUL (09/21/2009) — Bill Angell, a housing studies faculty member in the University of Minnesota’s College of Design and Extension housing technology specialist, is one of the world’s foremost experts on the presence of radon gas in homes and played a crucial role in designing new radon recommendations published today in Geneva by the World Health Organization (WHO). The new guidelines say that radon gas levels in homes should be lowered to about one-third of the previously recommended threshold.

Radon gas is the second leading cause of lung cancer and a class-A carcinogen. The lower threshold means that the number of homes needing radon mitigation in Minnesota will increase by 400,000.

Angell, president of the American Association of Radon Scientists and Technologists and chair of the Prevention and Mitigation Working Group in the WHO International Radon Project, said the revisions were necessary.

“WHO’s advocacy for more protective guidance to home buyers, builders and residential property owners reflects the growing evidence of the serious toxic risk posed by indoor radon,” said Angell. “It is important that all home buyers and property owners test homes they are considering purchasing or living in and consider reducing concentrations that exceed the new WHO recommendation.”

The Environmental Protection Agency (EPA) ranks Minnesota fourth highest in the nation with dangerously high levels of radon.

“Our risk is higher in Minnesota partly due to our geology—soil in the Upper Midwest contains widespread uranium—and partly due to having our homes closed up so much of the year to stay warm,” Angell said. Many homes in Minnesota and this region have basements with greater amounts of soil contact than other types of foundations and thus have a greater chance of elevated indoor radon.

In Minnesota, about 42 percent of homes that have been tested have indoor radon concentrations higher than EPA’s current threshold for action. At WHO’s recommended threshold for action, the portion of Minnesota homes with elevated radon increases to 60 percent, or from 900,000 to about 1.3 million.

In the "WHO Handbook on Indoor Radon: A Public Health Perspective," the organization recommends that countries adopt a threshold equal to 2.7 picocuries per liter (pCi/L). The previous level, supported by the EPA for the past 40 years, was 4 pCi/L. While the lung cancer risks of high dose radon, typically found among uranium miners, have been known for many years, new studies summarized in the new WHO handbook confirm that low levels of exposure to indoor radon contribute substantially to the occurrence of lung cancer. Radon is the primary cause of lung cancer in people who have never smoked.

WHO is calling on countries to establish or strengthen plans to control radon, which occurs naturally outdoors but indoors is the result of construction lacking proper methods of keeping the radioactive gas from seeping in through basement floors and walls. Although the best option may be to live in a home that is built with radon defense in mind, testing for radon and lowering the level is simple and inexpensive in any home. Angell says that if new recommendations are followed there would be 9,000 fewer lung cancer deaths per year in the United States, including several hundred fewer annual deaths in Minnesota.

For more information on radon in homes, visit:

WHO Handbook on Indoor Radon: A Public Health Perspective: http://www.who.int/ionizing_radiation/env/radon/en/index1.htm

University of Minnesota Extension Housing Technology resources: http://www.extension.umn.edu/HousingTech/

WHO Radon Web site: http://www.who.int/ionizing_radiation/env/radon/en/index.html

U.S. Environmental Protection Agency: http://www.epa.gov/radon/

Minnesota Department of Health: http://www.health.state.mn.us/divs/eh/indoorair/radon/

To order low-cots radon test kits: http://www.radon.com/sub/mn/