Indoor air pollution with gas stoves

Gizmodo, Oct 2020

One recent report found that gas stoves spew out levels of air pollution inside that would be illegal under outdoor regulations.

“It’s really a cocktail of emissions that they put out,” Brady Seals, senior associate of building electrification at the Rocky Mountain Institute who co-authored the study, said. “There’s the emissions from the gas itself, the main ones of which are nitrogen dioxide, carbon monoxide, and formaldehyde. And then there’s the particulate matter, or the small pollution particles, that come from the stove flames and from the food that’s getting cooked.”

Each of these toxins can enter the human body when we inhale, causing respiratory issues, especially for those who have chronic breathing conditions like asthma. The teeniest bits of particulate matter are so small that they can also pass through the lungs into the bloodstream and even the brain where they have been linked to anxiety and problems with attention and memory.

All that pollution can be mitigated by ventilation hoods, but people don’t tend to use their hoods enough. That’s partially because some of the toxins stoves produce aren’t detectable to the naked eye or nose.

“Carbon dioxide and nitrogen dioxide are invisible odorless pollutants,” Seals said. “The most particulate matter is mostly produced by burning food, which you can see and smell the smoke so it might make you turn on your ventilation, whereas the carbon monoxide and the nitrogen dioxide are really produced every time you turn on your gas stove, whether or not you’re burning.”

Countrywide data on hood usage doesn’t exist, but according to research recently presented to the state of California’s energy commission, just 30% of gas stove users surveyed across the state said they used hood ventilators when cooking. Further observation showed that people only use their range hoods half of the time they say they do, meaning in actuality, only some 15% of Californians are likely venting their stoves’ pollution.

To make matters worse, some homes don’t even have hoods. And in practice, hoods’ efficacy varies widely. One 2012 study found that in the U.S., the best hoods capture 98% of stoves’ emissions, but some hoods the authors examined vented as few as 15% of stoves’ emissions.

“We know everyone doesn’t have good hoods, and that’s especially true…for lower-income families,” Daniel Aldana Cohen, director of the Socio-Spatial Climate Collaborative at the University of Pennsylvania, said. “Gas stoves are an environmental justice issue, right inside the kitchen.”

Even good hoods don’t work unless they’re positioned correctly. To vent emissions out of the home, hoods must be set up to push air into the outdoors. But many aren’t.

“It’s a little bit shocking that most appliances are required by law to be vented outdoors, but a gas stove with a range hood is not, so the regulations really vary by state,” Seals said. What you’ll find is that some people don’t have any hoods, but some have hoods that just recirculate the air around the home.”

It turns out that includes my own gas stove. I have a hood vent, which is attached to a microwave that hangs over the top of the burners. But that vent doesn’t lead anywhere—it just diffuses the pollution throughout my apartment whenever I cook.

Seals suggested I put a tissue on top of my stove burners (in the off position, of course) and then turn the hood ventilator on to see how effectively it ventilates pollution. “See if it pulls up the tissue. You can get a sense of how strong that suction is,” she said.

I tried this and learned that my hood sucks—or rather, it doesn’t. On each of my four burners, the ventilator left a tissue mostly undisturbed.

When she heard the panic in my voice, Seals offered some advice. She said most vents work better for back burners than front ones, meaning we’d be better off if we awkwardly leaned over to cook. Windows can help, too.

“Even opening a window for five minutes or less can make a big difference in having these pollutants leave the home,” she said.

Of course, though that can mitigate some of gas stoves’ negative health effects, it doesn’t change their climate impact. Gas ranges produce nitrogen dioxide, a greenhouse gas that’s 300 times more climate-warming than carbon dioxide. When it reacts with heat and the sun’s rays, it can also deplete the atmosphere’s ozone layer that protects us from radiation.

There’s also the problem of the natural gas itself for the climate. Last year, natural gas was the number one contributor to the increase in U.S. carbon emissions. Gas stoves are a small piece of that; even compared to other household equipment like air and water heaters, they consume a relatively small amount of energy and emit a relatively small amount of climate-warming greenhouse gases. But they still rely on a gas-powered grid to work and can lock in polluting infrastructure.

“If we don’t take out the gas stove, we’ll still keep putting in gas pipelines,” Seals said.

It’s clear that gas stoves simply can’t stick around, as great as they are for cooking compared to electric stoves. Luckily, though, those aren’t the only two options.

“The best alternative is induction stoves,” Aldana Cohen said. “Many of the world’s best chefs use them. They are way better for people’s health. They perform far better than conventional electric stoves.”

Unlike traditional electric stoves, which have coils that get heated by electricity, induction burners run on electromagnetism, making them more energy efficient. Since they only heat magnetic surfaces like iron pans, they’re also safer.

“It’s almost impossible for them to burn human flesh or cause a fire,” Aldana Cohen said. “If you leave a burner on and there’s no pot, nothing will happen, it won’t generate heat.”

I rent my apartment, so I can’t exactly replace my burners to preserve my health and the planet. But ultimately, this problem can’t be solved with individual action alone even if I owned my place.

There are some policies in the works which could expand the use of induction stoves. Earlier this month, New York City’s housing authority proposed replacing gas stoves with induction ones, but it set a deadline of 2050, which is too late from a climate and public health perspective. In California, Sacramento and Silicon Valley’s utilities have also started programs which let residents borrow induction cooktops, but it merely provides a temporary option. Some cities are also starting to ban new natural gas pipelines, which means any new construction will have to include electric solutions for cooking and heating.

“We need to ensure that no new buildings that get built can run on gas,” Seals said. “And we really need to start to tackle the thornier issues of the existing buildings, particularly low-income homes, and how we can unlock subsidies or incentives to change over those appliances.”

One incentive is public health. Seals said that if we begin to factor the health benefits into cost analyses of swapping out polluting infrastructure from stoves to pipelines, we’d begin to see how much money electrification could save the country in hospital bills for asthma and other issues. Aldana Cohen also said the country could make induction burners more affordable is through public procurement policies—programs where the government purchases goods and services.

“In particular, induction stoves could be required in all government-funded building upgrades—to public housing, subsidized housing, through programs like the Weatherization Assistance Program,” he said.

A program to move all homes away from gas cooking could create jobs. But more importantly, it could help ensure that all Americans can breathe more easily and ensure we have a livable planet.

In the meantime, I’m definitely going to open my windows while and after I cook. I’m also considering buying a single plug-in countertop induction burner, which you can get for $50. I know that won’t fix the structural problems. But honestly, the thought of cooking dinner without it is freaking me out.Dharna NoorPostsEmailTwitter

Staff writer, Earther