Air pollution isn't just an outdoor problem. Unhealthy fumes may be emitted inside your own home if you're cooking over an unvented gas stove.
Almost two-thirds of California households using gas burners in the winter without venting range hoods are exposed to gases that can cause breathing problems, according to a new study by a team at Lawrence Berkeley Laboratory.
"Homes are exceeding air quality standards, exposing people to toxins who shouldn't be," said scientist Brett Singer, who contributed to the study.
The Bay Area has strict rules about outdoor air pollution, with 18 "Spare the Air" alerts issued so far this season to ban the burning of wood or manufactured fire logs. There are also state ventilation rules for indoor furnaces and hot water heaters.
But our stoves are largely overlooked.
And while the majority of California homes have a vented range hood installed, research suggests that a minority of households use them during all cooking, according to the team.
The Berkeley researchers concluded that 62 percent of households using gas burners without venting in the winter are routinely exposed to excessive levels of nitrogen dioxide, 9 percent to carbon monoxide and 53 percent to formaldehyde, gases that can trigger respiratory problems and aggravate asthma and cardiovascular disease, especially in young children and older adults.
"If these pollution levels were outdoors, the state would be required by law to submit a plan for how to clean up the air," Singer said. "But they are inside a home."
Indoor pollution levels drop by half in the summer, when doors and windows are more likely to be open. The study, led by research scientist Jennifer Logue, is published in the journal Environmental Health Perspectives.
The findings underscore the importance of using a range hood while cooking, they note. Although the recommended size of a hood is influenced by range size, heat output and the size of the kitchen, the best hoods move at least 300 cubic feet of air per minute and are verified by the Home Ventilating Institute.