For decades, scientists have worked to clean up air pollution from factories, cars and power plants. But researchers are increasingly turning their attention to the air that people breathe indoors. And one appliance has come to the fore as a source of pollutants harmful to human health: the humble gas stove.
A new study from researchers at Stanford University sheds light on how much Americans may be exposed, indoors, to nitrogen dioxide, which comes from burning coal and gas and has been linked to asthma and other respiratory conditions.
The researchers found that, across the country, short-term nitrogen dioxide exposure from typical gas stove use frequently exceeded benchmarks set by both the World Health Organization and the United States Environmental Protection Agency. In the longer term, using gas or propane stoves meant that the typical American could breathe in three-quarters of the nitrogen dioxide levels deemed safe by the W.H.O. within their own homes.
As with outdoor pollution, disadvantaged households may be more exposed, the researchers found. Because gas more easily spreads throughout smaller spaces, people in homes smaller than 800 square feet were exposed to four times more nitrogen dioxide in the long term than people in homes larger than 3,000 square feet, the study found. Black and Latino households were exposed to 20 percent more nitrogen dioxide compared with the national average.
“We’ve done a really good job in this country of reducing outdoor pollution,” said Rob Jackson, professor of earth system science at the Stanford Doerr School of Sustainability and a principal investigator on the study, which was published on Friday in Science Advances. “But we’ve ignored the risks that people face indoors. And that’s the air that we’re breathing most of the time.”
And though home cooks who use a gas stove are particularly exposed to nitrogen dioxide, he said, “we’re getting a better handle on the migration of pollution down the hall, to the living room and the bedroom.”
