I've heard about radon but never dreamt it might be in my child's school. What is it?
Radon is a gas that occurs naturally in areas all over the United States. It is caused by the breakdown of uranium that is found in soil, rock and water.
Radon seeps into homes and schools through cracks in floors, walls and foundations. It also can be released from building materials or consumed in water from wells that contain radon. Levels of the gas can be higher in homes that are well-insulated and tightly sealed.
You can't see, smell or taste radon. The only real way to know if radon is present is to test for it.
How dangerous is it?
Radon is the second-leading cause of lung cancer in the country, causing 15,000 to 22,000 lung cancer deaths per year, according to the National Institutes of Health. The gas decays into radioactive particles that can be trapped in the lungs, damaging the tissue.
Right now, there is are no conclusive data on whether children are at a higher risk than adults from radon.
How much radon is too much?
The EPA says that any amount of radon above 4 picocuries per liter -- that's how they measure radon -- merits taking action. The World Health Organization has argued for a lower indoor standard, of 2.7 picocuries per liter.
But there is no known safe level of radon exposure. The EPA advises that homeowners take action even if they find radon levels between 2 and 4 picocuries per liter.
I've only heard about radon as a concern in homes. Is it also a concern in schools?
Yes. One survey showed that one in five schools nationwide have radon levels above 4 picocuries per liter -- a level at which the Environmental Protection Agency says a school should take action. The EPA estimates that more than 70,000 schoolrooms in use today have short-term radon levels.
Can radon levels in a home or school be lowered?
Yes. Radon reduction systems can be used to vent the gas and prevent it from building up. For more information about radon reduction, visit the EPA's website.
I thought radon only occurs in certain areas.
Some areas naturally have higher radon levels, but those areas have been found throughout the nation.
The EPA assigns each county a zone based on what the expected radon levels are expected to be.
Zone 1 counties have the highest expected radon levels. In Maryland, those counties include: Montgomery, Frederick, Howard, Calvert, Baltimore and Carroll. In Virginia, they include Fairfax, Stafford and Spotsylvania counties.
Prince George's, Charles and Anne Arundel counties are in radon zone 2, meaning indoor average radon levels are expected to be 2 to 4 picacuries.
The District of Columbia is in zone 3, meaning indoor average radon levels are expected to be less than 2 picacuries.
Still, the EPA suggests that every homeowner and every school district test for radon.
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