Will your kitchen gas stove make you sick? Will it cause asthma in your children?
Those questions came up again this week as federal officials clarified that have no plans to ban natural gas stoves, ovens or stoves, unlike Los Angeles, where the City Council last year instituted such a ban on new gas appliances, including kitchen appliances.
Although scientific studies show that natural gas stoves emit high levels of nitrogen oxides and other health-damaging pollutants, the relationship between these pollutants and human health remains unclear.
More on the science in a moment. But here’s the bottom line: if you’re using a gas stove, make sure your kitchen is well ventilated, ideally with an extractor hood that pumps the air outside, and if that’s not possible, use a filter of HEPA air. And make sure you use them when you’re cooking. They can be noisy, and people who own them often don’t turn them on.
Should you get rid of your gas stove? Emily Oster, an economist and data specialist at Brown University, has analyzed the research on the topic and offers this advice:
“If you have a gas stove, do you have to replace it tomorrow? No, unless you have a major respiratory problem,” said Oster, who also works with the National Bureau of Economic Research and writes about pregnancy and parenting data at parentdata.org. If you’re shopping for a new stove, she said , “and don’t particularly commit to cooking with fire, I’d say do an induction stove.”
Now, the nitty-gritty: Natural gas is mostly methane, a fossil fuel that emits greenhouse gases as its blue flames burn. Proponents of gas stove bans often cite reducing carbon emissions as their primary goal, but they almost always cite health concerns as well.
There’s no doubt that cooking with natural gas emits harmful chemicals, including nitrogen oxides, carbon monoxide, and formaldehyde. Several studies have noted that pollutants emitted by gas stoves (before being vented) can exceed levels that would violate California Air and Environmental Protection Agency standards if the air outside were that polluted. And studies have shown that leaking natural gas pipelines cause indoor and outdoor air pollution.
But the scientific research behind the health effects of natural gas stoves is complicated and inconclusive. Although some studies have found a significant association between gas stoves and the prevalence of asthma or asthma symptoms in children, no direct causal relationship has been identified between the use of gas stoves and poor Health.
Given the difficulties in conducting such research, especially the multitude of variables that tend to confound the results, it is difficult to come up with a clear answer. And given the limitations of the available data, even the associations and correlations raise questions.
“We don’t have a lot of data on that,” Oster said. For a comprehensive study on asthma, he said, “Ideally, the kind of study you’d want to do would compare households in the U.S. that you know use gas stoves and those that don’t, and link that to health information , such as whether children get asthma or not. We don’t have those numbers.”
What scientists do have in this case is a large number of potentially confounding factors that could skew the results. How big is the cooking zone? Is there ventilation? How often is the stove used? Who else is in the house or apartment when meals are prepared? Is there mold behind the walls? If so, how can this be separated from emissions from gas stoves to reach health conclusions? Is there an apartment or house near heavy traffic? Are there heavy trucks rumbling down the street outside?
A 2020 report issued by UCLA and the Sierra Club that synthesized existing data reached the same conclusion as Oster: “The association between gas appliance use and health [including furnaces and water heaters] have conflicting results, partly due to study design limitations, but also due to a lack of data on quantified exposures,” the paper says.
Lead author Yifang Zhu, a professor at the UCLA Fielding School of Public Health, said, “There are definitely health concerns,” which deserve further study, but the evidence is not as substantial as people have made it out to be. made by the outside air.”
Like Oster, Zhu emphasized the importance of good ventilation.
Indeed, for poor people, subsidies for extractor hoods could improve indoor air quality more effectively than a gas stove ban, at least in the short term. Those who choose to replace their gas stoves with an electromagnetic induction stove need hundreds or thousands of dollars to do so. However, buyers could qualify for federal, municipal and utility rebates.
The UCLA report made it clear that it “does not compare the benefits and costs of electrification with improved hood use and efficiency in terms of reducing indoor air pollution “.
The source of most indoor pollution from gas appliances, the report notes, is from water heaters and furnaces. New installation of these appliances has been banned by the state of California, starting in 2030. There is no statewide ban on gas stoves, although Los Angeles and other cities have begun to follow suit example of Berkeley, which became the first city in California to ban. . new gas stoves in 2019.
The latest figures available for natural gas appliance use in California are from 2009, though an update is in the works. This survey showed that water heaters accounted for about 49% of a home’s average natural gas consumption, space heating 37%, and cooking 7%.