Sealing up houses to improve energy efficiency also traps more radon inside and may lead to a higher risk of lung cancer, according to a new study based on modeling.
Guidelines suggest people install ventilation systems when they try to reduce heat loss from their homes.
Many energy efficiency measures, like putting draft strips along doorframes, reduce air exchange, study author Paul Wilkinson said.
"Moreover, even where trickle vents (small vents in windows or bricks) are fitted, a proportion will not be used or will be left closed," said Wilkinson, from the London School of Hygiene and Tropical Medicine.
Radon, a gas produced from naturally occurring uranium in soil and water, is known to increase the risk of lung cancer. It is present in many homes in varying amounts.
The U.S. Environmental Protection Agency (EPA) estimates radon contributes to about 21,000 lung cancer deaths each year, mostly among people who smoke.
NEVADA - Elevated levels of radon have been found in 37 percent of the Carson City homes that have been tested, said Susan Howe, program director for the Nevada Radon Education Program through the University of Nevada Cooperative Extension.
Howe was in Carson City this past week to request that the board of supervisors declare January National Radon Action Month.
Howe said that the radon percentage is even higher — 56 percent — in the 89703 zip code, and nearly 43 percent in the 89702 area. In the 89706 neighborhoods, which include a portion of Lyon County, the percentage was nearly 22 percent, and in 89701, it was more than 26 percent. In 89705, which is mostly Douglas County, it was nearly 20 percent.
Radon levels are measured in picoCuries per liter, or pCi/L. Most households testing positive in Carson City were in the 0-20 range, some were up to 50, but one home in the 89701 zip code area measured levels of over 100.
The threat of radon makes this the season to be wary.
The gas that can't be seen or smelled but is the second-leading cause of lung cancer — smoking is No. 1 — is a particular peril to this area at this time of year.
"A lot has to do with the geology in this area," said Jerry Weyer of Radon Reduction Specialists in Manitowoc, referring to the traces of uranium in the regional bedrock that converts to radioactive radon gas as it decays. "But houses are shut tight at this time of year — that allows the radon to be sucked into the home."
Kerri and Howard Herrild found that out when they purchased their Ledgeview house in November. A radon test revealed that the gas levels in the home were above 4 picocuries, the radiation safety standard set by the U.S. Environmental Protection Agency.
With a 2-year-old in the house, the Herrilds spent $600 to have a radon reduction system installed before they moved in over the Thanksgiving weekend.
Extreme cold can have unusual effects in some unusual places. It can cause more radon gas to enter homes, and it can kill off tree pests. MPR's Cathy Wurzer spoke first with Bill Angell, professor, and housing specialist at the University of Minnesota, about radon. Then, she spoke with Lee Frelich, who studies forests and is Director of the Center for Hardwood Ecology at the University of Minnesota, about tree pests.