By Jeremy Schwartz
Peninsula Daily News
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Agency officials say, however, the risk of exposure to the odorless, colorless gas in specific homes can be known only after testing for it.
“If I were to look at that map and I had a home there, I would consider getting it tested. That would be the extent of my concern,” said Mike Priddy, Department of Health environmental health sections manager.
“I don't want to alarm people.”
Test kits are often inexpensive and can be found at many hardware stores and on the Internet, said Mike Brennan, a radiation health specialist with the state Department of Health.
“The only way of knowing whether or not you have high concentrations [of radon] in your house is to test,” he said.
The map, which can be found at http://tinyurl.com/PDN-RadonMap, shows that much of the high-risk areas are within the interior portions of Olympic National Park and in a band stretching along Clallam Bay and Neah Bay northwest to Cape Flattery.
High-risk areas are also shown in east-central Jefferson County, according to the map, with the remainder of the Peninsula shown at low- and medium-risk.
“It's something that certainly people should be aware of,” said Dr. Tom Locke, health officer for Clallam and Jefferson counties.
Locke said the map provided him with some new information about radon risk levels and is a good informative tool for the general public.
“People should not be alarmed, but they should be informed, and they should take action based on that information,” Locke said.
Radon is a naturally occurring radioactive gas that's odorless, colorless and tasteless, Brennan explained.
The gas seeps out of rocks and soils through the decay of radium, which itself is formed from the decay of uranium, he said.
Tim Walsh, chief hazards geologist with the state Department of Natural Resources and one of the developers of the map, said the risk level for the Peninsula and its mountains was based on overall occurrences of uranium in marine shale, which comprises most of the Olympic Mountains.
Radon can enter buildings through the ground and can persist in concentrations tens or even hundreds of times the level in outdoor air, according to the Department of Health.
The radioactive gas is most likely to build up in homes that have poorly ventilated basements, Brennan explained, or houses with no protective barrier between their crawl spaces and the living areas.
Variety of factors
The amount of radon coming through the ground depends on many factors, Brennan said, including the composition of underlying rocks and soil and the surrounding groundwater level.
Radon dispersed in the open air is harmless, Brennan said, but can cause cancer if it decays in people's lungs and is the second-leading cause of lung cancer behind smoking.
Ways of preventing radon getting into homes include ensuring that basements are well-ventilated so the gas does not have a chance to build up and making sure crawl spaces have good vapor barriers between the ground and the floor of the home, Brennan said.
“If [a vapor barrier] is stopping water vapor, it's probably doing a pretty good job of stopping radon, too,” he said.
“Many of the [methods] are just good building practices carried to where they should be.”
The federal Environmental Protection Agency has set radon levels of 4 picocuries per liter — a measurement of radiation in the air — or higher as the threshold at which efforts to lower levels should be made, Brennan said.
“If you're above 4 picocuries per liter, [the EPA] recommends you do something to lower the level,” Brennan said.
“I usually tell people to give me a call and [I'll] help them decide what will be the best choice, because there are a number of different ways to proceed at that point.”
Brennan said there is no safe amount of radon and reiterated that the only way to know how much, if any, of the gas is in a given home is to use a test kit.
“My strong recommendation is if you have any questions, test,” Brennan said.
“This is in my opinion a legitimate public health issue that can get addressed, and addressed effectively,”
To contact Brennan, phone 360-236-3253 or email him at Mike.Brennan@doh.wa.gov.
For more information about radon, visit the Department of Health's website at http://tinyurl.com/PDN-RadonDOH.
Reporter Jeremy Schwartz can be reached at 360-452-2345, ext. 5074, or at firstname.lastname@example.org.