At home with the NUCLEAR FAMILY

'Home sweet home' gets rocked by radon

by Steve Berberich

(Special to The Sunday Journal newspaper, 5/31/98 ed.)

David Drewry was surprised when a house he had purchased in Fairfax, Va., tested more than 2-1/2 times the U.S. Environmental Protection Agency safe level for radioactive radon, a potentially lethal gas.

But with a little sealing here and venting there, Drewry said he fixed the problem. And, he said, he has since sold the house.

"I know of only one house I can say where there will be no radon problem," said Drewry, owner of Drewry Home Inspection, Inc. "It is at the beach and on stilts."

Pamela Youngblood, a Maryland Association of Realtors spokeswoman, recently moved to Severna Park, Md., from eastern South Carolina, where, she said, "we never heard much about radon." But a radon test of her new Maryland home was "off the chart".

After the radon mitigation "it bottomed out below the EPA level," she said.

Throughout Fairfax County in Virginia and Montgomery County in Maryland, levels of radon gas have topped national averages recently. According to the National Cancer Institute, radon gas is responsible for an estimated 15,000 lung-cancer deaths a year and risk is especially high for people who smoke, the U.S. surgeon general warned.

Radon is found in rocks, and all rocks contain some uranium, according to the U.S. Geological Survey.

When the uranium breaks down into radium, radon enters the air; when inhaled, the gas can damage lung tissue. Radon moves faster through permeable soils, such as coarse sand and gravel, than through impermeable soils, such as clays and fractures in any soil or rock allow radon to move quicker.

Some soils in the Washington area have more radon than others, but in any neighborhood, radon can be detected in one home while a neighboring house could be radon-safe.

Tasteless, odorless and invisible, radon is harder to detect than other health hazards, such as asbestos, loose Fiberglas insulation, lead-based paints, microwave leaks, carbon monoxide or nitrites in drinking water that have detectable properties, said Drewry, a residential inspector for the County of Fairfax.

"In Northern Virginia, where you will find high radon readings, [radon] does not have a pattern," Drewry said. "You don't know what you're going to find."

"The thing about radon is that you can easily take action if your home has high readings," said Howard Rothchild of Enzone Inc. of Davie, Fla., which manufactures home safety test kits.

"Upcounty [northern and western] areas are much more prone to high radon," said Bernie Bloom, air quality program manager for the County of Montgomery. "The geology seems to be more favorable, I think, because the hard rock is much more thinly covered [by soil]."

Among the areas where high radon has been tested include Damascus, Clarksburg, Gaithersburg, Rockville and Derwood, all in Maryland, Bloom said.

"Still, some of the highest radon levels are in Takoma Park [Md.], even though Takoma Park is in a low radon zone," he said.

Bloom said he suspects that high readings are attributed to the age of many of the houses because older homes lack proper ventilation.

Although testing for radon is voluntary in Virginia and Washington, it is required that an EPA-approved laboratory is used; Maryland does not have any requirement for testing for radon.

"All over the metro area in the last month, we have gotten a lot more high readings," said Therese Ashman, spokeswoman for Accurate Radon Inc., an EPA-approved testing laboratory in Vienna, Va. Ashman, who tests more than 1,000 homes a year, said the highest readings of radon have been in Great Falls, Sterling, Fairfax Station and Oakton, all in Virginia.

To test for radon, she unseals a canister that is capable of absorbing only radon. After 48 hours, radon molecules to be counted are measured in the lab.

Wet weather may force more radon up through a house because wet ground around the house is sealing it in, Ashman said.

USGS said radon in water moves six to 10 times slower than in air. When a house is built, the excavation creates a vehicle for the radon, or a stack effect, to let it in.

Thomas Murley of Abode Check, a home inspection company in Fairfax, said 20 percent of the homes he checks have had radon levels higher than the EPA safe level of less than 4 picocuries (pCi), named for physicist Marie Curie, who pioneered research on radioactive elements in the late 1800s.

"It is a very solvable problem. A radon mitigation system involves sealing all cracks in the basement or lower level of the home. The cement that pulls away from a foundation should also be filled," he said.

Murley then recommends that a 4-inch pipe be installed to vent radon from below the foundation, up through the house, to above the roof, and out. He said a hole is drilled into the foundation to place the pipe.

"Accumulated radon under the floor will want to go up the pipe and out," Murley said.

The fickle fate of radon, house to house, is sometimes explained, said Murley, by a house that happens to be built over a sandstone fissure in the earth that permits escape of radon.

"Next door, radon might be low and it might not be necessary to mitigate," he said. For a radon test, he adds $150 to the home inspection invoice.

Steve Eyres of Home Tech Systems, a home inspection company in Bethesda, Md., said the radon issue is blown out of proportion because the EPA safe level has been set too low. He said some European countries are more realistic in setting safe levels at 10 or 20 pCi, he said.

One out of every 10 homes inspected for the Washington area by Eyres' company tests higher than 4 pCi.

"The metro area does not have very high rates overall, but we have high readings in certain pockets of Old Town Alexandria, [Va.] in certain areas of Fairfax County and in northwest D.C.," Eyres said.

But Christy Miller, indoor environment specialist with the EPA, said, "If you were a uranium mine and giving off a radon level of 4, you would be shut down."

Miller said EPA recommends that homeowners conduct two tests. A short test "may be an anomaly," she said. A second, long-term test of 90 days to one year is recommended to accurately determine radon levels, she said.

Radon testing laboratories must pass an EPA proficiency test before being approved, she said. EPA does not regulate radon, she said, but has issued periodic advisories since 1988.

"Because of the nature of the real estate market, we are doing the two-day test, then we do a longer test if it is high," Eyres said.

Older homes often have higher radon levels because of poor of deteriorating construction that lets the radon enter, he said. Newer homes can also be a problem, though, if they are "more airtight," Eyres said.

In Maryland, Miller said she has found high readings in the Muddy Branch area of Gaithersburg and Shady Grove, as well as Frederick and parts of Howard and Anne Arundel counties, all in Maryland. The highest was a reading of 123 pCi in an Oakton, Va., home. One of the highest readings in the Washington area measured by Enzone was 216 pCi in Fairfax (zip code 22031), Rothchild said.

Bloom of Montgomery County, and Steve Church, director of Fairfax County Department of Health's Environmental Monitoring Section, have developed maps of their respective regions that include map identifying radon zones of their counties. The maps are available to the public.

"When you apply the results of a National Academy of Science study [of health risks of radon] to Montgomery County, it suggests that there are over 50 deaths per year from radon exposure. That makes radon a very serious issue," Bloom said. He said he is concerned that 80 percent of radon testing is performed for real estate transactions.

Bloom's latest figures of 34,000 homes tested in the county showed 63 percent tested below 4 pCi. Another 26 percent tested between 4 and 9.9; testing between 10 and 19.9 were 7.3 percent; testing between 20 and 49.9 were 3.2 percent; and 1.5 percent of Montgomery County homes tested above 50 pCi.

"There is no law in Maryland that says people need to get mitigated of radon," he said, "yet testing is cheap, $20 or $30."

Nationwide, Radon Service Agreement Company, based in Atlanta, has found a corporate market in radon testing.

"Say IBM wants to transfer an employee from Washington, D.C., to upstate New York, and the company wants the employee to have a smooth real estate transaction into a new home. That is where we come in," RSA President Michael Kimmell said. RSA works relocation companies nationwide to arrange for testing and mitigation.

"These are usually subsidiaries of large insurance companies like Prudential or Sendel," Kimmell said.

"We created the concept of guaranteeing a radon test for a corporate employee relocating. Then we expanded the idea to serve corporations," he said. Two smaller companies provide similar services, he said.

In the nation's capital, RSA's government clients have been limited to the FBI, Social Security Administration and the Secret Service, but Kimmell wants to land military clients, too.

The EPA provides brochures on radon protections and said it is more cost-effective to include radon-resistant techniques while building a home, rather than installing a radon mitigation in an existing home. Materials and labor costs for radon-resistant techniques and mitigation is $350 to $500 compared to $800 to $2,500, a potential saving of 128 percent to 400 percent, according to the EPA.

Radon-resistant construction techniques provide an average of $65 per year in energy savings for the homeowner, according to the EPA.

"There are five major parts to the radon-resistant system: 1. a layer of gas permeable material under the foundation (usually 4 inches of gravel); 2. plastic sheeting over that material; 3. sealing and caulking all openings in the concrete foundation floor; 4. installation of a gas-tight 3- or 4-inch vent pipe that runs from under the foundation through the house to the roof; and 5. a roughed-in electrical junction box for the future installation of a fan, if needed.

"These features create a physical barrier to radon entry. The vent pipe redirects the flow of air under the foundation, preventing radon from seeping into the house," according to EPA literature, available from the agency's Indoor Pollution Division, (202) 564-9441.

The World Health Organization and the U.S. Department of Health and Human Services classify radon as a Class A known human carcinogen because of biological and epidemiological evidence showing a link between exposure to radon and lung cancer in humans.

The largest was an international study, led by the National Cancer Institute, which examined 68,000 underground miners who were exposed to a wide range of radon levels. The miners are dying of lung cancer at five times the rate expected for the general population.