Unsafe levels of cancer-causing radon gas have been found in 16% of tests on Chatsworth homes as reported by the California Department of Public Health.

The dangers of radon are documented in numerous long-term studies. Radon-influenced lung cancer kills more Americans every year than drunk drivers, according to the U.S. Environmental Protection Agency .

Radon naturally occurs throughout the United States. It comes up through rocks and soil from uranium deposits deep in the earth, so a home does not need to be on top of a toxic waste dump or near the Santa Susana Field Laboratory to be affected.

"The EPA says that radon is the No. 1 naturally-occurring health hazard of all time," said Dr. Steve Oppenheimer, director for the Center for Cancer and Developmental Biology at California State University Northridge.

In 2005 the U.S. Surgeon General issued an advisory on radon that stated, "Indoor radon is the second-leading cause of lung cancer in the United States and breathing it over prolonged periods can present a significant health risk to families all over the county."

The database shows that 32 out of 199 tests on homes in Chatsworth's 91311 ZIP code had unsafe levels of radon. That means about 16%--or one in six tests of Chatsworth homes--had radon levels higher than 4 picocuries per liter, written as 4 pCi/L. That is the level considered unsafe by the EPA.

Tests done in other Valley areas resulted in levels both higher and lower than 4 pCi/L. More than 32% of tests in homes in Woodland Hills and 30% of tests in Northridge revealed unsafe levels. West Hills, Sherman Oaks, Tarzana, Sylmar, Granada Hills and Encino also recorded numerous high readings, while little or no radon exposure was recorded in many other areas.

According to Steve Roquemore, a certified radon inspector based in Chatsworth, the database contains information provided voluntarily by independent inspectors like him who are hired by individuals or companies to do environmental tests.

"It's in all houses to some extent," said Oppenheimer. "One house might have a very high level, and the next one may have almost nothing, so you can't really tell which houses will have radon and which houses don't."

What the database does not provide is specific test locations or exact radon levels.

"We report only the ZIP code of the test site and whether the result was above or below four (pCi/L)," said Roquemore who operates Affordable Inspection Services out of his Chatsworth townhome. His partner (and wife) B.J. Rogers is also a state-certified radon inspector.

The couple's experience with radon is both personal and professional. Tests of their own residence showed radon levels as high as 6 pCi/L.

"Our townhouse has a bonus room that's subterranean on two sides," said Roquemore. Elevated radon levels are most often found in basements or other below-grade spaces.

The Bright Side

The good news is that it is fairly easy and inexpensive to test for radon and fixing a radon problem doesn't have to be a nightmare, either.

"Every single homeowner or apartment dweller should test their house for radon," said Dr. Oppenheimer. "In my personal opinion, every time a house is sold there should be a required radon test. There's a required termite test, but I don't know anyone that ever died of termites."

California residents can purchase radon test kits at a reduced price from the Dr. Home Air website. They can also be found in most of the large hardware or home improvement stores.

Most are simple to use but it's very important to read, and follow, the directions in the kit, testing expert Roquemore cautioned.

Proper location of the test canister is critical to an accurate reading, as is prompt return of the unit to the lab.

"Don't be cheap–send it to the lab overnight so you'll get the most accurate results," he said.

Should the test kit show radon levels between 4 and 9 pCi/L, the EPA recommends doing a long-term test, usually conducted by a certified inspector over a six-month period.

"With radon, it probably requires years and years of exposure [for lung cancer to develop], but you live in your house for years and years and years," Oppenheimer said. "It's odorless, it's tasteless, it's colorless. You don't know it's there. If you're living in your house for years you're probably exposed. It just depends on how much exposure you get in your particular house."

Unlike other home risks that most of us are more familiar with--such as asbestos or lead--radon can be dealt with fairly easily. In some cases, it may mean just opening windows and airing the place out regularly.

For more cautious homeowners or those who test at higher levels, there are mechanical systems to get rid of radon. These vary slightly, depending on whether your house is built on a slab or over a crawlspace, but basically they consist of a pipe that goes from below the house and vents above the roofline. A small fan pumps the bad air outside, where it dissipates harmlessly.

Most systems installed in our area cost around $3,000, said Roquemore. Homeowners' insurance usually does not cover the cost. Be sure to use a state-certified mitigation contractor.

Better Awareness Needed

Despite California Gov. Arnold Schwarzenegger's declaration of January as Radon Action Month, many Californians aren't aware that radon is a very real health risk.

Judith Daniels, president of the Chatsworth Neighborhood Council, was one of the few who did have an awareness of radon from her time living back east. But, she said, "I hadn't heard of it in Los Angeles. I thought that radon was almost exclusively a problem where houses were built with basements."

The Neighborhood Council had not been made aware of the state's radon report, and Daniels said she will be passing it on to her public safety committee to look into.

"I would think this is really more than just something that a neighborhood council should be tackling," said Daniels. "It's not a solely neighborhood issue. It's more widespread than that so I would think that it would be something at the very least the county health department should be informing people about."

Even the local City Council representative for Chatsworth, Greig Smith, was uninformed about the radon issue affecting his district. Smith was traveling when contacted for a comment for this story, but his office released a statement that opened, "We've heard very little information about the high radon levels in the San Fernando Valley." The statement went on to say they would be discussing it with the L.A. County Health Department.

Additional Resources:

The EPA has a wide variety of educational materials on radon risks, testing and remediation for everyone from school-age children to contractors to special population groups at their website: http://www.epa.gov/radon/pubc/index.html.

The California Department of Public Health also has a variety of publications and information available at: http://www.cdph.ca.gov/healthinfo/environhealth/Pages/Radon.aspx

--Studio City Editor Mike Szymanski contributed to this article.



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