An Interview With the Author of the Gas Stove Study That Made Headlines Around the World
Brady Seals' study on gas stoves went viral last week. I interviewed her to learn more about her research.
A few weeks ago, Brady Seals and a team of researchers published a study showing that 12.7% of childhood asthma cases can be attributed to gas stoves. Immediately the study was covered by news outlets around the country.
A few days later, Bloomberg reported that a commissioner at the Consumer Product Safety Commission was considering a ban on gas stoves. Suddenly gas stoves were all over headlines, cable news, and social media.
Last week, I interviewed Seals to learn more about her research on gas stoves.
Note: This is the first time I’ve published a full-lenth interview like this. I’d love your feedback on what you liked and didn’t like.
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What we cover in this interview
Why are so many environmental nonprofits focused on gas stoves and their health risks?
Why are gas stoves bad for our health?
Gas stoves make up a tiny fraction of the gas industry’s revenue. But based on how much money organizations like the American Gas Association are spending on stove-related campaigns, it seems like they really care about this product line. Why is that?
The backstory of the gas stove study that made headlines around the world
How has the gas industry responded to the study?
Is ventilation an effective way to reduce pollution from gas stoves?
How much do gas stoves contribute to climate change?
Induction stoves explained
How NY Times food columnist Melissa Clark became an induction evangelist
How can the Consumer Product Safety Commission regulate gas stoves?
Why doesn’t the EPA regulate indoor air pollution?
How does the Inflation Reduction Act help people replace their gas stove with electric and induction alternatives?
What are cities and states doing to regulate gas stoves?
Do gas fireplaces produce unsafe indoor air pollution?
What’s Brady’s theory of change for how gas stoves get phased out?
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(Note: This was transcribed by AI, not a human. Apologies for any typos).
Michael Thomas 0:00
Brady Seals, thanks so much for sitting down for this interview.
Brady Seals 0:03
Thanks for having me. It's great to be here.
Michael Thomas 0:05
I write a newsletter about climate change, you work for RMI a think tank that focuses on energy and climate. But we're going to be talking a lot about health risks associated with gas stoves. Why are so many climate activists, environmental groups, like RMI so focused on indoor air quality and public health right now?
Brady Seals 0:23
It's this old adage, right? Like, if it's bad for the climate, it's probably bad for your health and vice versa. So at RMI We, of course come at a climate lens. But when we first started looking at gas appliances in your home, which is really only a few furnaces, water heaters, clothes dryers, gas stoves, the more we talked to experts, the more we were hearing that gas stoves have this outsize health risk. And so we talked to some people who said they've been studying this for 2030 years. And yet the information just wasn't out there. And so I think that more and more climate and health are related. We're seeing climate folks talking about health, we're seeing health folks talking about climate, and the gas stove is almost this perfect microcosm where it it really affects everything. And so many of us have a gas stove or have cooked on a gas stove at some point, that I think it makes it really tangible. And it brings both climate and health as a kitchen table issue.
Michael Thomas 1:30
Can you tell me why gas stoves are bad for people's health and specifically, why no to or nitrogen dioxide is so harmful for human health?
Brady Seals 1:39
Gas stoves emit a lot of the same pollutants that come from our car exhaust. So, for example, the Environmental Protection Agency, the EPA, they regulate six of the most common pollutants, and many of those come from our gas stove. So these are things like carbon monoxide, nitrogen dioxide, particulate matter, also things like formaldehyde. And so these pollutants are being released when we're cooking, or when we're turning the gas stove on. And they're essentially staying in our homes. Most, many people don't have ventilation or adequate ventilation. So these pollutants are lingering in the kitchen, they may be spreading through the home. And we spend a lot of our time inside almost 90% of our time. And this was even pre pandemic that maybe that number has gone up. So we're spending a lot of time in a place and a gas stove is emitting these pollutants. So it's one of our primary sources of indoor air pollution at home.
Michael Thomas 2:42
Gas cooking is a couple percent of the gas industry's revenue, it makes up a very small fraction of the gas used in a home in any given year. But if you look at how industry groups like the American Gas Association have responded to this, it seems like they're really worried. Why do you think that is? Why do you think such a small product line is something that they're so worried about?
Brady Seals 3:06
Well, you have to hand it to the gas industry, they have had a genius marketing campaign. The other day, I even heard a toddler say Now we're cooking with gas. And this marketing campaign and this sort of crusade to make Americans love their gas stoves or think that we do is very real. And so like I said before, you have only a few gas fired appliances in your home, you're probably not standing in front of your furnace, or your water heater, but your gas stove, you're cooking meals for your family, you're boiling water to make tea and coffee. It's something that's a part of our everyday lives. And so I think for the gas industry, it's the first and the clearest link for the consumer and the the the gas that fuels it.
Michael Thomas 3:56
In your latest study, you and your co authors found that 12% of childhood asthma cases can be attributed to gas stoves, I'd love to hear a little bit of backstory on how that study came to be and what you found in the research.
Brady Seals 4:08
Sure. Yes, so we knew that gas stoves were bad. 50 years, I think the first study that I saw, and I know, Michael, that you have looked at this too, so you correct me if I'm wrong, but the first study I saw was in 1973. So we have about 50 years of this and we knew that it was bad. But we didn't have a good way to put it into context. Like how bad is it? How bad is it in the US? So there was a study in Australia by an epidemiologist named Luke nips, so we got in touch with him. He's great guy. And we said, Do you think we can do this study that you did in Australia where they found the 12.3% of asthma was from gas stoves, linked to gas stoves, do you think we could do this in the US? And he basically said, yeah, it's just math. And the funny thing about this study is that it's so simple that it's like almost boring. But yet, there's a lot of press about it right now. So what this study did is it looks at the population attributable fraction. So we were able to take Luke's methodology from Australia, which was peer reviewed and published. And then a meta analysis from 2013, which shows that children who live in a home with a gas stove have a 42%, increased risk of asthma symptoms. So we had these two numbers, and then all we had to do was apply it to census data. One thing that we found that was really interesting was, we know that 35% of US households cook with gas. So over a third of us cook with gas, but the households with children that cook with gas are actually higher. So we found that almost 43% of households with children cook with gas. So from there, it was basically a straight statistical analysis question. And that's where we got this 12.7% of childhood asthma is linked with gas. And so we're not saying that gas stoves are causing childhood asthma, the population attributable fraction is more about the strength of the relationship. And we had that number, the relative risk from the lens study. So once we apply that we were able to get national numbers, and 12.7%. Okay, what does that mean? Well, when we look at other other population attributable fractions, that's really similar to children's risk of, of asthma from exposure to secondhand smoke. So I think most of us know that secondhand smoke exposure is not great. But how many of us know that gas cooking could have a similar risk? So that was our goal was to really just put it into into context. But at the end of the day, it's pretty simply a math equation.
Michael Thomas 6:47
How has the gas industry responded to the latest studies that you've put out in particular, really this study?
Brady Seals 6:54
I'm glad that you brought that up, because we we did just see a response from them. So one, one of the first points is, hey, this newest study didn't look at actual homes with measurements and things like that. And that's true, what we did was even better, we looked at a meta analysis that looks at all those individual studies. And so because they can aggregate that their results, they have a different results and effect size, and it can be better. So people like to use meta analyses, because you're not just relying on one study, but you're looking at the whole strength of evidence. So that's the first point. The second point is they say, Well, why didn't you include the study that looked at 500,000 children or, or something like that, and the study, I believe they're referring to is a study by Wong. And this study was actually a self reported questionnaire of preteens around the world from 31 countries, as well as parents of six and seven year olds. So there wasn't any kind of measurement of health outcomes. But the main reason that we didn't include this study was because it was global. So they took these 31 countries in Asia, Africa, us and then compile them. So we we were looking at just US or Europe studies. So we weren't able to include the the pieces that they found. Interestingly, so the meta analysis that we used, one of the same authors from the from the Netherlands was on both of those, both of those papers. And he said in a previous interview interview with end news, that essentially the strength of the Linde study is much stronger, and that you can't just you know, we can't take one study and throw out the whole rest of the research that's been there. So I would say those are the two pieces of pushback that we've seen the most. And another one that we've seen from a couple of maybe health health folks or epidemiologist is about causation versus correlation. So I said it before, but we aren't saying causation in the study we're talking about associated with correlated with link to, and the population attributable fraction is really about the strength of the relationship. I'm not proposing to say causation. I think there will be future studies. In fact, some that are going on right now in California, which are randomized control trials, essentially the gold standard for studies on gas stoves and asthma that can get us closer to those kinds of information. But to date, we didn't have a study like that.
Michael Thomas 9:31
One of the other responses that I've seen a lot, both to some of your work, and then also whenever I've written about this, I received this question is what about ventilation? And you see a lot of industry groups that say ventilation is the solution not phasing out out gas DOS, is ventilation and effective solution.
Brady Seals 9:53
Ventilation is great. I love ventilation. Did I always ventilate. You know, to be honest with you, I used to only turn on my I rangehood if I was burning something and visibly seeing or smelling smoke, I'm not sure how many people out there like me. But ventilation is great, but it's not effective. Unfortunately, ventilation doesn't work for three main reasons fully work, I should say. One is that a lot of people don't have ventilation. I've definitely lived in places where I didn't have ventilation. You can see photos in magazines or on Zillow of kitchens with islands and no rangehood overheads. So it's very common, and it's actually wild because all of our other appliances are vented outdoors, except the gas stove, the one that we are standing in front of, for a large portion of our day to the ventilation that does exist is often inadequate. So I personally have a recirculating rangehood, it's in my microwave, and it just moves the air around instead of transferring it to outdoors. Also it Michael, I don't know if you've seen some of these studies. But the capture efficiency or how well rangehoods work is really bad, like sometimes they only actually remove a small fraction of the pollutants that are coming out. And so the folks like the the people at Lawrence Berkeley National Lab, who have done so much on this tell us that we should be cooking on the back burners, because that's where our range has our most effective. And then the third, and probably the biggest piece is that people just don't use them. So there have been some surveys and some studies. Unfortunately, there is no data set on how many people have ventilation. I know, for example, at LBNL. And the places where they've done research on this, they've had to look at Zillow and try to do an estimate of how many homes they can find that actually look like they have ventilation. So people people don't use it. And what the studies have shown is that sometimes 2030 40% of people say they always use their rangehood. Lawrence Berkeley National Lab, again, recently did a study where they asked people how often they use them, and then they went actually measured. And you can have these little devices on stoves that see when they get hot and turn on. And they found that people actually use their rangehood half the time that they say that they do. So for ventilation to be working, you'd have to have an effective rangehood that vents outdoors to be over both of your burners and to be using it every time you cook. So I think it's a little bit of an imperfect solution, although important to use it if you can, because of course cooking food also releases some pollutants and range has are actually more effective at particulates at removing particulates than gases like the ones from gas stoves.
Michael Thomas 12:52
So even if everyone uses their ventilation, even if all of those range hoods have 100% capture efficiency, and they actually work like they're supposed to in the lab in people's homes, we still have the problem of climate change. How much do gas stoves contribute to climate change? And how much should we be concerned with this issue?
Brady Seals 13:17
Well, gas stoves compared to other appliances in our homes are a smaller percentage of the emissions. Cooking is a smaller percentage. However, it's not as small as we once thought. So in the last couple of years, researchers from Stanford and physician scientists, engineers or PSC have actually been going around and looking at how much methane is leaking from people stoves. So as you know, methane is a really potent greenhouse gas has a huge warming potential. And what they found is that about 1% of all of the gas that's delivered to a stove is leaked in our homes as unburned methane. So 1% from a stove doesn't sound like a lot. But when you add that up, but 1% from 40 million stoves is actually they estimated the climate impact of half a million cars on the road. So we are significantly under estimating the climate impact of gas stoves if we account for methane leakage, which also by the way, is probably also leaking other chemicals and air toxins along with methane and things like benzene. So the leaking is certainly not good for climate and also not good for health.
Michael Thomas 14:31
When some people hear gas bans, or they hear about states like California and New York phasing out gas and new construction, they think that the only alternative is traditional electric stove. So they might think of the coil electric stove in their grandma's house, or those ceramic ones that are very responsive. Can you tell me a little bit about induction stoves?
Brady Seals 14:54
Yes, induction stoves need a much sexier name, but they're a very cool appliance. So induction stoves look a little bit like your ceramic electric stoves, but they actually work using magnetic technology. So these stoves are extremely common in Europe and other places in Hong Kong, it's less than 5% market share here. So it's not surprising that a lot of people haven't heard of induction or haven't cooked on induction. I hadn't cooked on it till a couple years ago. But induction stoves are super efficient. So they are about 90% efficient. And you compare that to gas stoves, 35% efficiency, huge gains, and what that translates into, they are really, really fast. So they boil water and half the time as gas. Actually, the only complaint I've ever heard from people who switched to induction is that when you first start using it, you tend to burn your food a lot, because it's just so fast. The precision, so lots of top chefs use it Eric Rippert, who you might know he uses that at his home. He said in two in two hours, he was in love with induction. So lots of chefs are turning towards inductions. It's it's common and lots of Michelin starred kitchens. But you went to Home Depot, and you don't see an induction stove. And I think this is where it's a little bit of an out of sight out of mind. But they are really great. Oh, the other thing people love, like even my family, you think that climate and health would be at the top of their list, but they're like they're so easy to clean. So they have a lot of benefits, which I think is really great, because if you're worried about gas stove pollution, you don't have to go to an electric coil stove, you can go to an induction stove. And now there's actually up to $840 of a rebate as part of the inflation Reduction Act. Wow.
Michael Thomas 16:51
You were recently interviewed by Melissa Clark, a New York Times food columnist for a story about induction. My understanding is that she was initially a skeptic. And then she ended up coming around in her reporting. Can you tell me a little bit backstory on that interview? And what Melissa Clark ended up writing about?
Brady Seals 17:08
Yes, that was one of my favorite interviews, because I'm a huge Melissa Clark fan. And I have all her cookbooks. So getting to have an interview with her was great. So she lives in New York. And in New York, a lot of the conversation is around all electric buildings for the future. So she said to me, you know, Brady, I totally get it from climate and health, but our induction stoves there yet. And so she ended up getting a plug in induction stove, which is how a lot of people this is how I got into induction as well. You can buy one of these plug in induction stoves. I think I got mine for $60. And so she did her own experiments. She's like, I'm going to cook with induction and see how it is. And so she actually took the knobs off her gas stove, and she put them in a drawer. And she put sheet pans on top of her gas burners and put her induction plugins on top. So she basically turned her gas stove into an induction plug in birder. And she started cooking with it. And again, she was really impressed with how fast it was the precision I think she talked about, like cooking garlic or cooking onions and getting distracted on her phone and that they were they were fine. And so she she at the end of her story said that she was planning to cook on induction for two weeks. And it had been four weeks and she hadn't looked for. She hadn't looked for her knobs yet. And I emailed her when her latest study came out. So when did I talk to her back in March? So it's been a few months. And I said, you know, Melissa, the study did you get did you get your new induction stove yet? And she said, she said I can't wait. But I'm still cooking on my induction plugin burner. So even if you're someone who loves to cook at home, I think it's a great option you have this middle step of getting creative in the kitchen and and turning your your kitchen station into a induction plugin. So I think that, you know, chefs and everybody is one thing, but it's really the home chefs and the foodies who are cooking at home without the ventilation systems of restaurants who are more at risk of gastro pollution. So having people like Melissa Clark and she she interviewed Chefs for her story is really key to see that people like the cooking experience.
Michael Thomas 19:27
I'm talking about policy, we've said the the most exciting. So this week, the Consumer Product Safety Commission came out and said that they were considering regulations on gas stoves. And the media has made some misleading claims about this. Some of the comments were a bit confusing. conservative pundits and Republicans in the House and Congress have taken to Twitter talking about this. Can you tell me a little bit about the Consumer Product Safety Commission and how they can regulate gas stoves.
Brady Seals 20:03
So gas stoves are technically a consumer product. And that falls under the authority of the Consumer Product Safety Commission or the CPSC. They regulate lots of things, baby cribs, baby toys, all kinds of things that have to meet certain criteria to keep us safe. How is it that gas stoves are not regulated? This is crazy. We have had gas stoves that our homes for like, just so long, yet, they don't have to mean any kind of performance, standard. And so within the CPSC has authority, there are several things that they can do. Lately, advocates and also policymakers have been calling on the CPSC. To do more, you know, this risk has been going on for so long, why hasn't anything happened? So they have a suite of options. It can be things starting at warning labels, people don't know about this educational campaigns people don't know about this. I really think CPSC should get busy on mandatory performance standards, we should be assured that the gas stoves that are coming into our homes aren't releasing elevated levels of pollutants. Just a couple of days ago, a certain brand of gas stoves was recalled because of their high levels of carbon monoxide, which they had to get, I think over 44 complaints from people. And carbon monoxide is something you can't see or smell. It's deadly. And also, as I recently learned, it can spread through drywall, so your neighbors, if you live in an apartment gas stove may be your concern. So I think there are several different options. To be clear, the CPSC can't go and take anyone's gas stove. So there are 40 million gas stoves out there, the the CPSC isn't going to be going and pulling those out of out of our kitchens. Any regulation would apply to new stoves. And so I think it's going to be really fascinating to see what tools the CPSC decides to use in the coming years, especially after the pressure from consumer advocates and policymakers.
Michael Thomas 22:11
Before this week, I thought that the only federal agency that we're going to be talking about in this interview was the Environmental Protection Agency. The EPA regulates outdoor air pollution, why doesn't it regulate indoor air pollution?
Brady Seals 22:24
This is such a good question. Why doesn't it we spend 90% of our time indoors, and the EPA website says indoor air maybe two to five and occasionally 100 times more polluted than outdoor air. But it's a black box when it comes to indoor air. What the EPA does have authority to do what they can do what Canada did what some states have done like California is set indoor air quality guidelines. So these are non binding regulations. But what they can do is give us benchmarks like right now we're essentially building buildings blind building without safe benchmarks or gas stoves aren't meeting any kind of health protective benchmark. And so having these health based guidelines, which by the way, the World Health Organization just updated, and really dramatically, so last year, could help us with building codes and things like that that would then become regulations and become binding. So EPA does have an indoor division, they raise a lot of awareness. They do some good work on schools. But I do think it's time for EPA to think about setting indoor air quality guidelines. They've done it with radon. So there is a precedent to that. And I think EPA could work closely with CPSC on this issue.
Michael Thomas 23:48
Last year, Congress passed a bill that offers incentives for people that want to make the switch from electric to or from gas stoves to electric alternatives like induction, you mentioned this briefly. But I'd love to ask again. What kind of rebates and tax credits were in the IRA, both for electric cooking and then also for electrification more broadly?
Brady Seals 24:10
Yes. So the IRA is probably the biggest climate bill I will ever see in my lifetime. It's very exciting. And as people like to say, it's full of a lot of carrots. So there's a lot of incentives, which means people have to want to do these changes and get electric appliances. So when it comes to gas stoves, there's up to $840. It depends on your income and what you qualify for within your area. And that could be for any kind of electric stove, induction stove, electric smooth top stove, but the really exciting thing is let's say you have a gas stove. Many gas stoves have electric ovens. I don't know if you knew this, but this is sort of a thing where electric ovens are just better and so high end gas stove may have an electric oven because it distributes heat more evenly and has a lot of benefits. So some gas stoves may already have a 220 volt outlet next to them, but many don't. And if you switch from different kinds of electric stove to induction, you may have only a 110 volt. So if you get your stove with your rebate, you may also need to upgrade your outlet, your panel and your wiring. And the really cool thing about the IRA is that they offer 1000s of dollars for wiring and panel upgrades and things like that. rewiring America has this nifty calculator where you can type in your average income and where you live. And they'll give you an estimate of what they think that you could get. And I think when I did it, it was like over $14,000 with various electrification updates to my home. So I think that, you know, depending on your own situation, you could potentially be receiving up to 1000s of dollars to do the rewiring and get yourself set up with the modern induction cooktop.
Michael Thomas 26:07
Let's talk about city and state policy, something that gets a lot less attention. But where I think there's been a lot more progress on gas stove and indoor air regulations. What are cities and states doing to regulate gas stoves right now?
Brady Seals 26:23
It's so fascinating. So the first city to have a building electrification ordinance was Berkeley in 2019. That seems pretty recent to me, Does that seem recent to you? Okay. Since that time, so many cities and communities have passed various regulations, that's either preferring electric or requiring electric for new construction at Rmi, we have a tracker on this. And so we've calculated that it's over nine states and DC, and representing 31 million people. So 31 million people as of now are living in a place that has this electric preferred or electrical required building code update. And to me, like, it's pretty amazing, because this was, I think you could call it a grassroots movement. It was cities, it was small communities that were passing these kinds of ordinances. And a lot of it was driven by climate to in order to reach climate goals. And something that we've seen, and you mentioned this before, but is that sometimes gas stoves are exempted from these policies, maybe to not be too contentious, or whatnot. But if that happens, one, we know that there's this this health, this health harm. And so that's where I think the Climate and Health going together is really key. The second piece is that I think there's over 3 million miles of pipelines in this country. And the average age of them is something really old, if they're expensive to maintain, like you, like you mentioned. So if we, if we keep exempting gases, we're going to continue putting pipelines, which are expensive leak a lot of methane into these places. And so the the grassroots movement of this has been huge. We've now seen some states, Washington, California, New York, Massachusetts, looking at things at the state level, which is exciting. But of course, the gas industry is also active in something called preemption where there along with with various policymakers passing laws, which would prohibit a small local city or community to do one of these building electrification ordinances, preemption, or Tactus, that we've seen before, with things like tobacco.
Michael Thomas 28:46
Yeah. One of the concerns that I've heard from people when they hear that gas won't be allowed in new construction is what about my gas fireplace? I've also heard this in response to some of the writing that I've done. People asking what are the health impacts of gas fireplaces? My understanding is there's not as much research on this, but I'm curious how you generally respond to folks like that, that have concerns.
Brady Seals 29:13
This is this is so interesting. This is like my parents who give the gas the gas that was one thing but the gas fireplace on the other hand, so there's this is a really big, really big issue. Exactly. We don't have as much research on it, although we do have some, even from just up the road at CU Boulder who've done a little bit of research on this. So the big question here is unvented gas fireplaces are vented gas fireplaces, most of the new fireplaces are vented and so again, that may be better for indoor air quality, but we are transferring those pollutants outdoors where it will affect neighborhood level air quality. I think one thing that's concerning to me about gas fireplaces, especially after talking from the survivors, from like the National Carbon Monoxide association is, is just your one leak away sometimes have a leak, something you can't smell or detect. Carbon monoxide monitors often don't go off until there's a real problem. So if you have an underlying health health problem like cardiovascular disease, you may be feeling carbon monoxide issues at much lower levels than your alarm will pick up. So I think the risk of carbon monoxide leaks is is one like with many appliances, but for for gas fireplaces as well. I do think this is a topic that deserves more research. And I guess my compromise piece so Mom and Dad, this is says, you know, what we talked about is if you do have to have your gas fireplace, in my mind, it's much better if it is a distributed version. So like a small propane tank, versus getting your natural gas pipeline to go in. So it's not a perfect solution. But I do think that there are benefits over a distributed energy versus the infrastructure for for the gas, the gas pipeline. So as we all make compromises, I think that's that's one place.
Michael Thomas 31:15
And my final question. What's your theory of change from from here? Like? How do you think we get to a place where there aren't any gas stoves installed in America, or where people don't have the health risks associated with gas stoves,
Brady Seals 31:34
I think the future is really one where we go two ways. People who can afford to make the switch, need to want induction stoves need to see the superiority of the cooking experience, and also that you can get mac and cheese on the table and half the time. So I think there's a piece of just this, not that it's aspirational. But that is something that we want and we is monitored and is cool, and will make your life even better. So that that I think is happening because the technology is so great. We're already seeing induction stove companies innovating and installing stoves with batteries. So if the power goes out, you can cook meals and plug your refrigerator into them. So that's very cool. And I think we'll continue. And the other piece is that we know a lot of people can't make this switch on their own renters people in public housing. And so a big part of this will be on policymakers to protect residents to protect health, and to make sure when we do this transition to clean alternatives, that it's done fairly. And so as everyone else gets off gas, the low income folks aren't essentially holding the bag for everyone else and having prices increase. And I think this is a risk that has been talked about before and is one where careful planning of this transition with policymakers and Frontline communities will help to make sure that it's possible. So yes, I guess a mix of of the carrots and the incentives and the wanting to and then also the protections especially for renters, people who can't make these choices as easily as others.
Michael Thomas 33:23
Well, Brady Seals, thank you so much for coming and talking to me. I really appreciate it. Thanks. Great to be here.