Living in a newer home in Eastern Washington does not eliminate the risk of having elevated radon levels, even though building construction codes have required radon mitigation for nearly 20 years.
Washington adopted radon control standards in 1992 for new dwellings in “hot” counties, but Mark Gerard, co-owner of Advanced Radon Technologies in Spokane, said those standards are hardly a cure considering that many homes still have serious radon problems even with radon mitigation systems.
“The standard is written as a base minimum,” he said.
Radon is an invisible gas that seeps through the ground and collects inside of buildings. It is a known carcinogen and the second-leading cause of lung cancer after smoking.
And the Inland Northwest is a radon hot spot geologically.
Spokane is one of five northeast Washington counties with state-imposed rules requiring builders to install radon mitigation.
In North Idaho, there are no requirements for radon mitigation in new construction even though seven counties have high radon levels and local governments have the ability to impose mitigation standards.
Most radon problems are discovered during real estate transactions in which a buyer asks for a radon test.
Gerard said his company is currently working on a project to upgrade the system in a $750,000 home built a few years ago north of Spokane and recently sold to a new resident.
An initial test as part of the deal found a radon level of 20 picocuries, which is five times the level at which remediation measures are recommended.
An initial effort to upgrade the system by adding a fan to the main vent pipe dropped the level to 11 picocuries. A larger fan was installed, dropping the level to 9.
That led to installation of a more sophisticated system that is working, Gerard said.
He said two homes in the Athol area of North Idaho had readings of 150 to 170 picocuries.
Some builders install radon systems to a higher standard, in which case there is a greater likelihood that the radon levels are low enough to be safe, he said.
Homeowners who are not sure of the radon levels in their homes should start an investigation with a test kit available at home improvement stores.
If levels are higher than the U.S. Environmental Protection Agency standard, then remediation may be needed. The addition of a fan to a previously installed system may be enough.
In homes that have no system, simple ventilation and fresh-air intakes help, but they are not as effective as ventilating areas where the gas collects or enters the home, Gerard said.
The average residential installation costs $1,100 to $1,500.
The World Health Organization in its 2009 radon handbook compiles a summary of international radon research that shows that radon exposure is consistently linked to increasing risk of lung cancer. The more radon there is, the higher the risk.
As many as 20,000 lung cancer deaths may be caused annually by radon in the U.S.
“The models about how radon can cause lung cancer are pretty clear,” said Mike Brennan of the Washington Department of Health.