Gas stoves, found in more than 40 million U.S. homes, are likely giving some children asthma, new research suggests.
A study published Friday suggests that around 50,000 current cases of pediatric asthma in the U.S. are linked to long-term exposure to nitrogen dioxide from gas and propane stoves.
Nitrogen dioxide forms when natural gas is burned at high temperatures. It is known to irritate airways and worsen existing respiratory problems. Previous studies have also linked long-term exposure to new cases of asthma and chronic lung disease.
The new study, which researchers at Stanford University published in the journal Science Advances, suggests that the average yearly exposure to nitrogen dioxide from gas and propane stoves in U.S. homes may be close to the World Health Organization’s limit.
To reach those conclusions, the researchers measured nitrogen dioxide inside more than 100 U.S. kitchens while stoves were on and monitored how nitrogen dioxide spread to other rooms after the stoves were turned off. They accounted for various scenarios like windows being open or shut, burners on low versus high, and range hoods being on or off.
The team combined that data with information from a U.S. Energy Information Administration survey about how often people use their stoves and what indoor ventilation typically looks like. That yielded an overall estimate of annual exposure to nitrogen dioxide, which the researchers then used to calculate the approximate number of new asthma cases that would be expected as a result, based on past studies.
“If you don’t smoke in your home, then your gas stove is one of the largest sources of air pollution in your home,” said Yannai Kashtan, the study’s lead author and a doctoral candidate at Stanford’s Doerr School of Sustainability.
A 2022 study similarly found that 13% of childhood asthma cases in the U.S. were attributable to gas stoves.
On average, the new study found, gas or propane stoves account for a yearly exposure to nitrogen dioxide of around 4 parts per billion. The WHO’s annual limit is about 5.3 parts per billion for indoor and outdoor air combined.
The study also noted that exposures tend to be higher in smaller homes, those where people cook often and homes without a hood to vent air from the kitchen to the outdoors.
Homes under 800 square feet have four times the amount of long-term exposure to nitrogen dioxide compared to homes larger than 3,000 square feet, the research showed. Exposure in those small homes exceeded the WHO’s safe limit.
“We often focus on outdoor air quality, but the indoor sources — stoves being one of them — could be just as important, if not more so, because of the amount of time people spend indoors,” said Susan Anenberg, chair of the environmental and occupational health department at George Washington University’s Milken Institute School of Public Health, who was not involved in the research.
The study also revealed racial disparities in nitrogen dioxide exposure from gas stoves. American Indian and Alaska Native households had 60% more long-term exposure relative to the national average, while Black and Hispanic households had 20% more exposure. Poorer families also faced an increased risk.
“We found that poor people breathe dirtier air outdoors and — if they own a gas stove — indoors, too,” said Rob Jackson, a co-author of the study and a professor of Earth science at Stanford. “People in public housing and in poorer neighborhoods who often rent can’t switch their appliances because they don’t own them or they can’t afford to do so.”
The American Gas Association, a trade group representing energy companies that deliver natural gas, questioned some of the past research on which the new study relied.
It pointed to one paper which found that although cooking with gas slightly increased the risk of asthma in children, the result was not statistically significant. Because of that, among other reasons, AGA President and CEO Karen Harbert called the new study’s conclusions “misleading and unsupported.”
(The same paper, however, found that cooking with gas instead of electricity significantly increased the risk of pneumonia and chronic lung disease.)
Dr. Laura Paulin, a pulmonologist at Dartmouth Hitchcock Medical Center, said she often asks patients with lung disease about their cooking habits.
“Some people will say it themselves: ‘Every time I cook or every time my spouse cooks, I feel worse or have to leave the room,’” she said.
Even leaving the kitchen may not be sufficient, Paulin added: “We’re still seeing that the NO2 [nitrogen dioxide] concentrations are high everywhere — not just in the kitchen.”
To reduce exposure, opening windows or installing a range hood that vents outdoors may help, Jackson said, though it won’t eliminate the problem. His team also found that many people don’t use hoods due to the noise, and many hoods simply recirculate polluted air inside the home.
If possible, Jackson said, families with gas stoves could consider using a portable induction cooktop.
“Every time you’re boiling water for rice or noodles and you don’t have to turn your gas stove on, that’s a win for health,” he said.
Another option, Jackson added, would be laws that prohibit new buildings from installing gas stoves.
New York state passed such a policy last year: Electric heating and cooking will be required in some new buildings there by 2026 or 2029, depending on their height. Berkeley, California, also passed an ordinance in 2019 that prohibited natural gas hookups in new homes, but the city repealed the ban in March in response to a lawsuit by the California Restaurant Association.
“There’s such a viable alternative here that works the same way in terms of the use of the stove: electric stoves. It is not the case that we have to be stuck with these gas stoves,” Anenberg said.
However, at least two dozen states have passed laws prohibiting local governments from restricting gas use in buildings, according to an analysis from S&P Global Commodity Insights.
House Republicans have also introduced several bills that would limit regulations on gas stoves. Two of those bills passed in the House last year but stalled in the Senate. A vote on a third, the Hands Off Our Home Appliances Act, is expected next week.
