No doubt you have heard the discussion that gas stoves are evil … because they lead to childhood asthma. I am not talking about “gasoline” stoves—and I do not recommend you cook with gasoline—but gas stoves that run on natural gas. You might have one of these “anti-children” appliances in your kitchen. I recently moved from a home that had a gas stove to one where I now cook with electricity … not because I have children who are likely to develop asthma but because … well, the new house does not have a gas stove.

Why are we demonizing gas stoves all of a sudden? I think you know the answer. In an administration where the President has said, “I guarantee you, we’re going to end fossil fuels,” anything that uses fossil fuels as a fuel source must be ended. Gas cars, diesel trucks, gas stoves … they all have got to go.

But here at the Cornwall Alliance, we like to go a bit deeper. What is the science behind the connection between gas stoves and childhood asthma?

I turned to an article in the Washington Post in its Climate 202. I guess this is for “advanced” climate activists, not just the newbies who can only handle Climate 101. Nevertheless, the article is entitled, “Gas Stove Pollution Causes 12.7% of Childhood Asthma, Study Finds.” With a number of 12.7%—not just 12 percent or 13 percent but 12.7—you know it must be an accurate, in-depth study.

The study suggests that gas stoves are “on par with the childhood asthma risks associated with exposure to secondhand smoke.” That says a lot—in many different ways.

The Post article notes that gas stoves are used in 35% of households in the United States and emit significant amounts of nitrogen dioxide. They estimate that nearly 650,000 children are afflicted with asthma that arises from their parents’ using a gas stove to cook food.

Wow, that sounds scary. And who doesn’t want to protect our children? They even quote a co-author of the research as saying, “It’s like having car exhaust in a home.”

Wait … what? I’ve cooked on a gas stove. I also have stood behind my running car many times. You might have too. Trust me, the gas stove is not like having car exhaust in a home. This is hyperbole to the extreme. But, as usual, it scares the public, which is why the article exists in the first place.

Let’s look at the company who co-authored the research. It is RMI, the Rocky Mountain Institute, whose motto is “Energy Transformed.” It is an environmental think tank dedicated to research, publication, consulting, and lecturing in the field of sustainability, with a focus on profitable innovations for energy and resource efficiency. The lead author cites his affiliation as RMI, but he also is a research associate at Rewiring America, a “leading electrification nonprofit, focused on electrifying our homes, businesses, and communities.” If an oil company published a paper on the virtues of fossil fuels, or if a tobacco company published a paper on the benefits of smoking, or if a pharmaceutical company published a paper on the benefits of its vaccine … okay, let me not get too carried away … but if any of these happened, you can be sure that the Washington Post would have rejected the story out of hand as mere propaganda.

Not here. But I am willing to give even the fox a chance to plead his case that the chickens are perfectly safe in the hen house. The article, to its credit, is not a white paper published on the company website. It was published in the International Journal of Environmental Research and Public Health and was entitled, “Population Attributable Fraction of Gas Stoves and Childhood Asthma in the United States.” The journal has been cited for being lax on peer review, especially for special issues with guest editors, of which this paper is a part.

But let’s give the paper the benefit of the doubt and look at its substantive claims. The paper is not a difficult read; in fact, with all figures and references it is only four pages long. Four pages. I’ve read comments and editorials that were longer. That is not to say you can’t or shouldn’t be concise.

The paper is based on the calculation of the Population Attributable Fraction, as the title suggests. In epidemiology, the Population Attributable Fraction is the proportion of incidents in the population that are attributable to the risk factor. Here, the risk factor is exposure to a gas stove. So, the calculation is the proportion of the population of children who have contracted asthma from gas stoves.

The paper outlines the statistical methodology used by the authors. They use a particular equation to calculate the Population Attributable Fraction. The equation is fairly simple and uses as variables the proportion of households with children exposed to gas stoves and the relative risk of developing asthma given exposure to gas stoves.

I did a little looking through the literature because … as a scientist, that’s what I used to do for a living. Within ten minutes, I came upon an article entitled “Use and Misuse of Population Attributable Fractions.” Written in 1998, the article lists five formulas that are often used to calculate Population Attributable Fractions. Formula number 2 is exactly the equation that is used in our gas stove paper. With regard to this equation, the paper “Use and Misuse of Population Attributable Fractions” notes, “not valid when there is confounding of exposure-disease association” and “found in many widely-used epidemiology texts, but often with no warning about invalidness when confounding exists.”

What is confounding? From the University of North Carolina, “Confounding is an important concept in epidemiology, because, if present, it can cause an over- or under-estimate of the observed association between exposure and health outcome. The distortion introduced by a confounding factor can be large, and it can even change the apparent direction of an effect.” That is a huge bias and a significant warning.

Do we have any confounding effects here? Sure. Did the researchers address having a smoker in the household? The Washington Post admitted that the effect of gas stoves was as large as the impact of second-hand smoke. Did the researchers address genetic predisposition, the mode of birth delivery, breast versus bottle feeding, use of antibiotics, oxidative stress, or an industrialized lifestyle? All of these have an effect on childhood asthma. Nowhere in the vast four pages of the article were these or other confounding issues addressed or even mentioned.

But, come to think of it, I didn’t see any discussion of real data either, just a modeling study. One would assume they collected data on children with and without asthma and children in homes with and without gas stoves to determine the effect of gas stoves on the occurrence of asthma. No.

The authors took summary statistics for North America and Europe to generate probability distributions of both childhood asthma and children exposed to gas cooking. They then took 10,000 random values from each distribution and … voila … you have an average and a distribution from which confidence intervals can be computed. No data on children with asthma … just a model that is highly susceptible to confounding, which is prevalent in this study.

By the way … why use data from North America and Europe when the study—and its title—purports to be from the United States only? Well, as the authors concede, “we used the combined North America and Europe odds ratio for the relative risk in this equation, as childhood asthma in the US remains relatively rare, affecting 1 in 12 children.” Statistically, a probability of about eight percent is not considered a rare event, but can they assume that the effect of asthma in Canada, Mexico, and all of Europe are the same as it is here in the United States? Not likely, especially with all of the unconsidered confounding variables. This is flawed research no matter how you look at it.

Indeed, when pressed by the Washington Examiner, the authors relented on their claim by stating the study “does not assume or estimate a causal relationship” between childhood asthma and natural gas stoves; rather, it “only reports on a population-level reflection of the relative risk given what we know about exposure to the risk factor.”

Speaking of data, a 2013 study published in Lancet Respiratory Medicine considered half a million children in 47 countries over several years. Its conclusion? “We detected no evidence of an association between the use of gas as a cooking fuel and either asthma symptoms or asthma diagnosis.”

But, of course, the goal was to write an article condemning gas stoves, get it published in an academic journal, and then garner lots of public press in an attempt to get a ban on gas stoves. It apparently has worked in sixty-nine communities in California, and the California Air Resources Board has voted to ban sale of all natural gas appliances by 2030. Communities in Massachusetts as well as New York City and Seattle have banned gas in all new construction. As the study’s lead author has noted, “gas stove emissions are significant contributors to the climate crisis.” Let it be known that gas stoves account for only 0.4% of the total natural gas use in the United States.

So, without gas stoves, what are we to use? Electric stoves immediately come to mind. They run on fossil fuels … oops … or nuclear … or the not-so-clean and not-so-green wind and solar energy. But, as Maurice Strong, former Executive Officer for Reform in the Office of the Secretary General of the UN, said in his opening speech to the 1992 Rio Earth Summit:

“Current lifestyles and consumption patterns of the affluent middle class – involving high meat intake, the use of fossil fuels, electrical appliances, home and work-place air-conditioning, and suburban housing—are not sustainable.”

So, no … electric stoves are out. How about … wood stoves? It requires one to either cut down trees for fuel—and thereby reduce an important carbon sink—or use fallen trees which removes the habitat for animals and replenishment of soil nutrients in forests. Wood stoves are therefore out.

Dung? A quarter of the planet burns dried animal dung for energy, including cooking. Many activists don’t seem to think using dung for cooking is much of a problem because it puts carbon into the air that originally was taken out of the air by plants. So, it is a renewable energy resource. But burning dung should be prevented at all costs since burning it releases much greater amounts of dioxins and chlorophenols, and it has a higher value as a fertilizer. If you thought gas stoves were bad at polluting indoor air, dung is much higher up that list. Yes, dung stoves are definitely out.

And so are kerosene and propane stoves, as they use fossil fuels as well. So, what should we be using to cook? I guess the real answer is … nothing! Meat needs to be cooked, but we are supposed to give up meat because …  after all, we are now told animals are people too! And in some cases, animals are more important than people. But most vegetables can easily be eaten raw, which saves on energy for cooking. I guess the take-home message is that we all should become extreme fruitarians—where one eats only fruit that falls from trees or vines. In extreme fruitarianism, the goal is to refrain from harming the plant that created the fruit or vegetable and eat only what the plant has discarded. Or maybe we should again consider Acts 10:11–15 … tell me again, what was Peter told to do with the animals on that great sheet that descended in front of him?

This article is adapted from an episode of the Cornwall Alliance’s podcast Created to Reign.

Photo by Mykola Makhlai on Unsplash.