Does the gas stove in your kitchen make you sick? Will it cause asthma in your kids?
Those questions came to the fore again this week as federal officials cleared that they have no plans to ban natural gas stoves, ovens or cooktops — unlike in Los Angeles, where the city council enacted such a ban on new gas appliances, including kitchen appliances, last year.
Although scientific studies show that natural gas stoves emit high levels of nitrogen oxides and other harmful pollutants, the connection between these pollutants and human health remains unclear.
More on the science in a moment. But here’s the bottom line: if you use a gas stove, ensure your kitchen is well ventilated, ideally with a range hood that pumps air outside, and if that’s not possible, use a HEPA air filter. And make sure you use them when 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 scientist at Brown University, has analyzed the research on the subject and offers this advice:
“If you have a gas stove, do you have to replace it tomorrow? No, unless you have a significant 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 buying a new range, she said, “and you’re not particularly into fire cooking, I’d say get an induction range.”
Now for the details: Natural gas is mostly methane, a fossil fuel that emits greenhouse gases with its blue flames. Proponents of gas stove bans typically cite reducing carbon emissions as their primary goal, but they almost always mention health concerns as well.
There is no question that cooking with natural gas releases harmful chemicals, including nitrogen oxides, carbon monoxide and formaldehyde. Several studies have found that pollutants emitted by gas stoves (before they are vented) can exceed levels that would violate Environmental Protection Agency and California air standards if the outside air were just as polluted. And studies have shown that leaks in natural gas pipelines pollute the air inside and out.
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 established between gas stove use and poor health.
Given the difficulties in conducting such research, particularly the multitude of variables that tend to confound the results, a straight answer is difficult to find. 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 of asthma, she said, “ideally, the type of study you want to do would compare households in the US that you know use gas stoves and those that don’t, and link that to health information.” , e.g. B. whether children have asthma or not. We don’t have those numbers.”
What scientists have in this case is a large number of potential confounders that could skew the results. How big is the cooking surface? Is there ventilation? How often is the stove used? Who else is in the house or apartment when food is being prepared? Is there mold behind the walls? If so, how can these be separated from gas stove emissions to draw health conclusions? Is an apartment or house near heavy traffic? Outside, heavy trucks rumble down the street?
A 2020 report issued by UCLA and the Sierra Club, which synthesized existing data, came to the same conclusion as Oster: “The link between gas appliance use and health [including furnaces and water heaters] have mixed results, partly due to study design limitations, but also due to a lack of data on quantified exposures,” the paper said.
Lead author Yifang Zhu, a professor at the UCLA Fielding School of Public Health, said, “There are definitely health concerns” that deserve further investigation, but the evidence isn’t as substantive as what people have been doing for outdoor air. “
Like Oster, Zhu emphasized the importance of good ventilation.
In fact, extractor hood subsidies for poor people 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 cooker will need hundreds to thousands of dollars to do so. However, buyers may qualify for federal, city, and utility discounts.
The UCLA report clarified that it “does not compare the benefits and costs of electrification to improving the utilization and efficiency of range hoods in terms of reducing indoor air pollution.”
The source of most pollution from indoor gas appliances, the report finds, comes from water heaters and stoves. Reinstallation of these devices has been banned by the state of California effective 2030. There is no statewide ban on gas stoves, although Los Angeles and other cities have begun to follow the example of Berkeley, which became the first California city to introduce a ban on new gas stoves in 2019.
The latest available figures for natural gas appliance usage in California are from 2009, although an update is in progress. This survey found that water heaters accounted for about 49% of the average household’s natural gas consumption, space heating 37% and cooking 7%.