Minnesota: Reducing Exposure To Cancer-Causing Radon Gas
Beginning June 1, all new houses built in Minnesota will be required to include features designed to resist or reduce the infiltration of radon gas. State health officials say the change is an important step toward reducing Minnesotans' potential exposure to a cancer-causing gas, but more can be done to reduce radon levels in homes, with testing as the essential first step.
Radon is the second leading cause of lung cancer in the United States. More than 21,000 deaths are attributed to radon each year in the U.S. Radon is an odorless, tasteless gas that forms from the decay of naturally occurring uranium found in rock and soil throughout Minnesota. The primary radon exposure for most people is their home. Radon gets into homes through structural cracks and gaps. The Minnesota Department of Health (MDH) estimates that one in three homes in Minnesota have levels of radon gas that pose a large health risk over years of exposure.
Nevertheless, radon exposure is a preventable health threat. One of the most cost effective strategies is to include radon-reduction systems in all new construction, according to Joshua Miller, an environmental health specialist with MDH.
"The new requirements will help reduce new homeowners' potential exposure to radon," Miller said. "However, there is more that homeowners need to do to reduce their exposure. Even with these new systems, homeowners will still need to test their homes for radon to know whether they may need to do more to reduce their risk of radon-induced lung cancer."
The change to the state building code requires builders to install a "passive" radon mitigation system that does not include a powered exhaust fan. These systems reduce soil gas entry points and provide a route to vent the gases to the outdoors. A vent pipe is installed into aggregate beneath the basement slab or under a crawl space and extends through the roof. An electrical junction box is required to be roughed in the attic near the pipe, so that an active system with a fan can be added easily in the future if needed.
MDH encourages builders and homeowners to build to the "MDH Gold Standard" by installing a radon mitigation fan. This can make a big difference between a minimal reduction in radon as required by the building code and a maximum reduction of radon entering the home, thereby substantially reducing the lung cancer risk due to radon. A full mitigation system, with a fan, will not only reduce radon levels, but will reduce the likelihood of other indoor air contaminants that the building code does not consider, Miller said.
The changes in the law are welcomed by the American Cancer Society in Minnesota. "We're hoping more people will start to take radon gas seriously, considering it kills more than 300 Minnesotans each year," said Matt Flory, Health Care Director for the American Cancer Society (ACS). The ACS is a partner with MDH in trying to build awareness of the lung cancer risks associated with radon and what people can do to protect themselves.
Owners of older existing homes should not think they are stuck with radon. "Fortunately, radon problems in existing homes can be fixed," Miller said.
The first step toward reducing radon risk for anyone, whether they live in a newly constructed home or an existing home, is to test for radon. Homes should be tested about once every five years or after undergoing major structural changes. Test kits can be purchased from a variety of laboratories and range in duration from two days to one year.