Radon: how dangerous is it?


Radon is still a risk in many homes, according to the American Lung Association, which recently distributed information on the South Coast offering free radon detection kits to local residents.

Radon, a naturally occurring colorless, tasteless, and odorless radioactive gas, results from the decay of uranium, which is found in nearly all soils. The coastal region between Summerland and Monterey has some of the highest levels of radon in California, because the area it has large deposits of Rincon Shale, "marine rock approximately 17-20 million years old, laid down in the sea," said Professor Emeritus Robert Norris from UCSB's geology department.

"The Rincon [Shale] is a fairly prolific producer of Radon in our California coast," he said. "It forms a band along the South Coast from roughly the brush line down toward the sea.

The amount of radon (measured in picocuries per liter or pCi/L), in soil depends on complex soil chemistry, which can vary from one house to the next. Radon enters buildings by way of the ground through cracks and openings in the foundations. Once inside, radon can become trapped and unless the building is properly ventilated to remove the gas, it can become a health hazard.

Long-term exposure to elevated levels of radon increases the risk of a person contracting lung cancer. In fact, radon has been named to be the second leading cause of lung cancer in the United States - second only to smoking. For these reasons, the Lung Association is offering kits that will test for levels of radon inside dwellings as long as supplies last.

It's fairly extensive in this region. In this kind of climate, where you don't have your house all buttoned up all the time, and the wind's blowing through, it's probably not a major issue." Mattinson mentioned that although radon is a byproduct of one of several decays ultimately coming from uranium, it has a very short half-life.

Cigarette smokers should keep their exposure to radon as low as possible, since smokers have eight times the risk from radon as non-smokers. Smokers who reduce their radon exposure from 6 pCi/L to 2 pCi/L will receive as much beneficial risk reduction as the non-smoker who reduces exposure from 34 pCi/L to 2 pCi/L.

Families with a hereditary predisposition to cancer should be more concerned about radon exposure than families who don't have any history of cancer, and people with young children should be more concerned with the possible consequences of radon exposure than someone in their late sixties or seventies.

If a house tests below 4 pCi/L, most experts agree that there is a relatively low probability of a significant health risk to residents.

If a dwelling should test above acceptable levels of radon, there are several ways of mitigating the situation, said Bill Hobbs, owner of Radon Reduction and Research in Santa Barbara. Hobbs, also a math instructor at Santa Barbara City College, has been in the business of testing homes for radon levels for 12 to 13 years, he said, "since high levels of radon were discovered in houses built on Rincon Shale in the region."

Hobbs measures levels of radon using a continuous monitor, a calibrated electron device, to take readings over a 48-hour period in a closed house, he said.

According to Hobbs, Rincon Shale formations are prevalent in the foothill area above Cathedral Oaks Road from Winchester Canyon to close to Turnpike Road, from 154 to Mission Canyon and the Sycamore Canyon area and Summerland.

Hobbs said that the federal government's Environmental Protection Agency has published a number of worthwhile booklets about radon, including, "The Citizen's Guide to Radon" and "The Real Estate Buyer's and Seller's Guide," available through the EPA's Website at ww.epa.gov/radon. The site also has detailed maps showing radon prevalence in various parts of the country and other useful information.

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