By ANDREA MCCANN
Indiana Correspondent

WASHINGTON, D.C. — A silent killer may be lurking in your home, quietly stalking until it overtakes you. Radon, a colorless, odorless, tasteless gas, can seep into homes and other structures, unbeknown to the occupants – and the only way to detect its presence is to test for it.

“Any house can have radon,” said Dave Ryan, press officer for the U.S. Environmental Protection Agency’s (EPA) Washington, D.C., headquarters. “Despite where you’re located, every house in the United States should test for radon. You may have a problem, and the house next door may not.”

A naturally occurring radioactive gas, radon is released when uranium decays in rocks and soil. The radon gas itself then continues to decay, forming heavy metal elements, such as lead, that attach to dust and other particles in the air. These particles can be inhaled and embedded in the lungs, damaging cells and setting the stage for lung cancer.

“Radon is a gas that decays to form very small, solid particles that then have the potential to give off radiation,” explained Bill Field, a professor in the College of Public Health at University of Iowa. “Some attach to dust … it depends on the size of the particle, whether or not you inhale it. They embed in the lungs, further decay and can start cancer.”

The National Cancer Institute’s (NCI) website states that radon is present in most air, and people breathe it at diffused, low levels every day. It’s when the gas accumulates at a high level in a confined space that problems occur.

Field said adverse health outcomes are chronic, not acute; in other words, homeowners aren’t quickly overcome by radon gas, as they would be by carbon monoxide accumulation in a confined space. The effects are cumulative throughout a period of time.

Though much less common, radon also can be found in well water; it’s released and inhaled when showering or washing dishes.
According to the NCI, radon exposure is the second leading cause of lung cancer in the U.S. About 25,000 people die annually from radon-related lung cancer, Field said. While cigarette smoking far exceeds radon exposure in the number of lung cancer deaths, the majority of radon-related lung cancer deaths occur among smokers.
“Someone who smokes a couple packs a day gets more radiation exposure than nuclear workers are allowed to receive,” Field said.
The reason, he explained, is that when radon decay products are released from the soil, they can be deposited on tobacco leaves, ultimately exposing smokers through their tobacco products. Couple that with high radon levels in the environment, and there’s a synergism that acts almost like a multiplying effect.

“It enhances the effect of the outcome, which is lung cancer,” Field said.

Certain occupations also may expose workers to unacceptable radon levels. They include uranium and other hard-rock miners, radon mitigation testers and contractors, natural-cave employees, phosphate fertilizer plant workers, oil refinery workers, utility and subway tunnel workers, employees at underground nuclear waste repositories and those remediating radioactive contaminated sites, water plant operators, fish hatchery attendants, construction excavators and power plant workers.

If radon exposure could be an issue on the job, employees must talk to the boss. At home, however, there are steps homeowners can take themselves. “If you’re building a house, it’s important to talk to the builder about radon-resistant structure,” Field said. “More and more cities are requiring it.”

To prevent that, Field explained, a couple of inches of stone under the foundation and a ventilation system will go a long way toward making a structure radon-resistant.

 “Radon comes from a lot of different types of soil and rock that underlie a home. It comes in through cracks in the foundation of a home. Because of the way we build homes, they tend to accumulate radon. Once inside, it tends to build up compared to concentrations outside.”

The EPA website states that the concentration of radon in a home depends on the amount of uranium in the underlying rock and soil, routes available for passage into the home and the rate of exchange between the indoor and outdoor air. Among ways radon can invade the home are cracks in the foundation, the crawlspace, sump pump, floor and wall joints, drains and pores in hollow-block walls.

In existing homes, testing is crucial. There are three kinds of radon detectors available and a list of suppliers may be obtained from national or regional health departments.

Some detectors may be found in home improvement stores, but to accurately reflect true exposure to radon, instructions must be followed carefully. Field recommends following EPA protocol for radon testing.

The agency’s radon hotline number is: 800-SOS-RADON (767-7236). If radon is detected, Field said, it’s important to talk to a mitigator. Lists of qualified mitigators and information on test kits may be found through a state’s health department or the EPA website at www.epa.gov/radon/whereyoulive.html

According to Field, installing a depressurization system and/or sealing off the source, such as a sump pump or open hole, may be necessary. In most cases, he said, a depressurization system also helps reduce moisture and mold. Sealing cracks, floors and walls and improving ventilation are other simple ways to reduce radon levels.

He added that radon removal can be applied on a health-care spending account.