WHO Cuts Radon Limits after Studies Find More Danger Than Once BelievedSep 23, 2009 | Parker Waichman LLP We recently wrote about how radon gas was linked to increases in lung cancer risks based on emerging studies. This is important because radon, an odorless and colorless gas, can be found in many homes.
Now, the Associated Press (AP) is reporting that the World Health Organization (WHO) has significantly reduced radon amounts derived from natural sources that are allowed to accumulate in buildings. The reduction applies worldwide, said the AP, and was made due to radon’s links to deadly lung cancer.
According to the Environmental Protection Agency (EPA), radon is a cancer-causing radioactive gas. Radon gas from natural sources can accumulate in buildings and reportedly causes 21,000 lung cancer deaths per year in the United States alone. Radon is the second most frequent cause of lung cancer, after cigarette smoking, and radon-induced lung cancer is thought to be the sixth leading cause of cancer death overall. The AP noted that radon gas can be found in “mines, caves and water treatment plants” but can also be “contained in rocks and soil” which can easily enter buildings, such as houses, through small fractures and gaps in the structures.
In 2005—two years after the EPA released its figures—the U.S. surgeon general issued a national health advisory warning about indoor radon, said the AP. The amount of radon in the air is measured in “picoCuries per liter of air,” or “pCi/L,” and the EPA said 4 pCi/L is the level of radon exposure that requires someone to take action. The EPA also said levels lower than that “still pose a risk” and “in many cases, may be reduced.” According to a 2008 New York Times article, 4 picoCuries is “about the same risk for cancer as smoking a half a pack of cigarettes per day.”
The WHO issued a new handbook that recommends countries establish home limits on the deadly gas at 100 becquerel per cubic meter, said the AP. The WHO’s limit, which was set in 1996, permitted radon exposure at 10 times that limit, added the AP.
"Radon is the second most important cause of lung cancer after smoking in many countries," said Dr. Maria Neira, with WHO and a specialist on health and environment, quoted the AP. "Most radon-induced lung cancers occur from low and medium dose exposures in people's homes," Dr. Neira added.
According to Wolfgang Weiss, UNSCEAR’s vice chairman, in a news conference, reported by Reuters last year, prior radon risk estimates were taken from studies of uranium miners who had been exposed to high radon levels, not of general consumers. This, in part, led to the move to establish improved standards.
Of concern, the WHO stated this week that, based on worldwide studies from 2005 and 2006, radon in homes is more dangerous that first believed and is a “significant” factor in 3-to14 percent of lung cancers globally, reported the AP.
Test kits are available for home use to inexpensively determine radon levels, said the AP, which added that, in the United States, it is recommended that home radon levels be tested every two years.