The research provides “yet more evidence of why we need our regulators and our policymakers to be protecting us from these consumer products,” said Brady Seals, a manager at RMI who co-authored the study.
The study was led by the sustainability-focused nonprofit RMI and is based on data from nine states. It comes as part of a growing body of research on the dangers associated with cooking with gas, countering the industry narrative natural gas is a “clean” fossil fuel. A June study, for instance, found that the natural gas used in homes in Greater Boston contains toxic pollutants like benzene and toluene. A separate 2020 report from RMI found that gas stoves create levels of air pollution inside that would be illegal under outdoor regulations.
Seals said the researchers chose to focus on childhood asthma because it’s the health impact for which there is the clearest evidence of a link to pollution from gas stoves.
Asthma, the top chronic disease in children globally, affects some 5 million children across the country. The new analysis suggests that close to 650,000 of US children may have asthma because of gas stove usage in their homes. It also indicates that the level of risk attributable to exposure to gas stoves is comparable to the risk associated with exposure to secondhand smoke.
To quantify that correlation, the researchers analyzed 2019 census data, relying on risk calculations established in previous studies. They borrowed their methodology from a 2018 Australian analysis that found that 12.3 percent of childhood asthma cases in that country was attributable to gas cooking ranges, and drew data from a 2013 analysis that found that children living in homes with gas stoves were 42 percent more likely to experience current asthma symptoms and, over their lifetime, 24 percent more likely to be diagnosed with asthma.
“We just took those two studies, and then we applied the methods to US census data using just basic statistical analysis,” Seals said.
She noted that census data from 2019 shows that 35 percent of households in the US cook with gas, but that the proportion of households with children that use gas stoves was even higher, at 42.8 percent. Similarly, in Massachusetts in 2019, 41.9 percent of all homes had gas stoves, but 53.3 percent of households with children did.
Brita Lundberg, chair of the board at Greater Boston Physicians for Social Responsibility who co-authored a December 2019 resolution on the connection between gas stoves and childhood asthma approved by the Massachusetts Medical Society House of Delegates, said the findings were “not shocking” but still distressing.
Seals agreed but said they also deliver a glimmer of hope.
“They suggest we can do something to improve things,” she said.
One potential way to lower risk is to improve ventilation, said T. Stephen Jones, a retired epidemiologist with the Centers for Disease Control and Prevention, who did not work on the study. Another option, he said: cutting down on gas stove usage.
“Instead of heating the water for your coffee on the stove, you might have a kettle that plugs in, or you might use a microwave instead of cooking on the stove,” said Jones, who was another co-author of the 2019 Massachusetts Medical Society resolution.
Still, 2022 research found that gas stoves emit methane — a potent greenhouse gas — even when they are turned off, meaning the appliances are a problem for the climate even when they’re sitting idle.
The best option is to focus on switching to gas-free appliances such as electric resistance stoves and induction stoves, said Robert Jackson, a scientist at Stanford who has studied methane leaks from gas stoves.
“Better ventilation can reduce people’s risk, but electrifying our homes is the safest way to eliminate indoor pollution from gas stoves,” he said. “No child deserves to have asthma [from] breathing indoor pollution from gas stoves when safer electric alternatives exist.”
The gas industry has long promoted gas stoves as the best possible cooking appliances, but Seals said clean stove technology has vastly improved in recent years. In addition to improving indoor air quality, she said, these alternatives are more efficient, meaning they can help lower utility bills.
“And then there’s the fact that they can [boil water] in half the time, and that they’re really easy to clean,” she said.
Amid growing public concern about the health risks associated with gas stoves, lawmakers are also attempting to reduce reliance on them with policy. A 2021 Massachusetts climate bill, for instance, contains a provision allowing 10 communities to ban the use of fossil fuels in new buildings and major renovations. Ninety-four cities and counties across nine states and Washington, D.C., have also adopted policies that require or encourage the move to all-electric buildings. And last month, a commissioner on the US Consumer Product Safety Commission Commissioner said that a federal ban on gas stoves is a “real possibility.”