Cooking with a gas stove may be as bad as breathing secondhand cigarette smoke, study finds

LOS ANGELES — Cooking with gas-fired stoves can cause unsafe levels of toxins to accumulate inside homes, exposing people to roughly the same cancer risk as breathing secondhand cigarette smoke, according to a new study.

Researchers from Stanford University and nonprofit PSE Healthy Energy tested gas and propane stoves in 87 homes across California and Colorado and found that every appliance produced a detectable amount of cancer-causing benzene — a chemical with no safe level of exposure.

It only took 45 minutes for a single burner on high, or an oven set to 350 degrees, to boost benzene levels above well-established health base lines, according to the study, which was published last week in Environmental Science &Technology. In some cases, benzene levels exceeded concentrations found in secondhand tobacco smoke.

Scientists also found that benzene migrated well beyond kitchens, reaching unhealthy levels in other rooms and lingering within homes for hours. The toxic conditions, researchers found, were even worse in smaller homes, suggesting health risks may be worse for lower-income families with less square footage.

“That ties into it being an environmental justice issue too,” said Yannai Kashtan, lead researcher and Stanford PhD candidate in earth system science. “A lot of folks either can’t afford to replace their stove, or maybe are renters and their landlord doesn’t want to. Also, lower-income folks are more likely to be living in smaller spaces where the same emission rate is going to translate into a higher concentration.”

Gas stoves have been a fixture in American kitchens for over a century. But a growing body of research has exposed a plethora of contaminants and health consequences from cooking with gas.

The research — the first of its kind to examine benzene emissions from cooking — comes as politicians across the nation are sparring over the future of gas appliances in residential and commercial buildings.

Last year, the Los Angeles City Council voted to ban most gas appliances in new buildings, a move intended to mitigate gas energy’s contribution to global warming. New York, San Francisco and Seattle have passed similar regulations.

California air regulators have been considering phasing out gas appliances as well, to meet the state’s ambitious climate goals.

But just last week, however, the Republican-controlled House passed a bill that would prevent the U.S. Department of Energy from banning gas stoves, a move the American Gas Association hailed, saying it protects a consumer’s right to choose.