Gas stoves can harm your health — and scientists have known that for decades

The United States’ never-ending culture wars have moved to the kitchen, as Republicans turn up the heat on nascent efforts to shift Americans away from gas stoves.

One could be forgiven for thinking that this surge in attention stems from groundbreaking new research that shocked scientists and policymakers. But the truth is that air quality scientists have been documenting the dangers of gas stoves since the 1970s.

“It’s a pretty long-standing literature spanning at least 40 or 50 years,” said Jon Levy, an environmental health researcher at Boston University. “I think it starts from the intuitive sense that if you’re burning a fossil fuel inside your home, it can cause air pollution.”

“This was already being actively looked at based on the literature to date under the Reagan administration,” said Levy. “What’s been coming up recently, it’s new, but it’s also extremely old.”

Decades of research

Gas stoves work by combustion, igniting natural gas to produce heat. But a blue flame isn’t the only product of that chemical reaction; burning gas also produces pollutants you can’t see or smell. Particles of varying sizes — most notably PM2.5, particles whose diameter is one-thirtieth that of a human hair — get spewed out during combustion, along with carbon monoxide (CO), nitrogen oxide (NO) and nitrogen dioxide (NO2).

Scientists have loads of data on the health impacts of these pollutants, especially NO2, though many of these studies focused on air outdoors, since regulators have historically been more interested in pollution from industrial factories or cars. Research into indoor air quality is a relatively newer field, “but there’s no real reason to think that nitrogen dioxide you breathe outdoors affects your body any differently than breathing it indoors,” said Josiah Kephart, an environmental epidemiologist at Drexel University. “It’s the same molecules in the same bodies.”

Just how much NO2 builds up from gas stove use depends on how much gas is emitted and how quickly the air can be cleared. “NO2 levels are proportional to how much gas a stove burns,” said Eric Lebel, a senior scientist at P.S.E. Healthy Energy, a nonprofit science and policy research institute. “And the concentrations of NO2 that build up in a kitchen depend on how big your kitchen is and ventilation levels,” he said.

Disproportionate harms

Getting a handle on precisely how harmful gas stoves are to children and adults is inherently more challenging than just measuring the concentrations of gases in homes, but a worrying picture is emerging from observational studies. The clearest threat is asthma.

“The data are pretty robust,” said Stephanie Holm, a pediatric environmental medicine specialist at the University of California San Francisco. Children’s smaller, still developing lungs are especially susceptible to this kind of pollution, Holm said, and the level of exposure really matters. “There’re data showing that in families that use ventilation, kids are less likely to have asthma than families who are not venting.”

There are other health concerns, too, though the weight of evidence varies. Cardiovascular issues, diabetes, cancer and reproductive problems have all been linked to NO2 and gas stoves. In general, the evidence is less robust for non-respiratory illnesses, said Holm. “But I think the evidence base is strong enough to support stronger regulations around gas stoves,” she said.

“Is there more that we can learn? Absolutely. But we know enough to know that they’re harmful,” said Holm. “Why would I wait to find out exactly how harmful? Why would I put myself and my kid at that kind of risk?”