Did you see the headline about how cooking with a gas stove is reasonably safe especially if you have good equipment and adequate ventilation? Of course you didn’t. No major news outlet ran such a headline, even though the statement is accurate.
Instead, the Denver Post’s Matt Sebastian Tweeted the following summary of a story in the paper: “Cooking with a gas stove in your home is like living with a smoker, new Stanford University research conducted in metro Denver finds.” I responded, “I notice the words ‘can’ and ‘depending’ in the lede of the article, which are pretty important qualifiers!” When I looked a few days later, the headline atop the story said using such a stove “can be like living with a smoker.” Better! Then the implication is clear: It also can not be. And it usually isn’t.
Reporter Noelle Phillips’s lede says the of benzene present depends “on ventilation and the size of the house.” The further you read, the more qualifiers you find. Phillips quotes the Stanford-produced study as saying benzene “may increase health risks under some conditions.” By paragraph fourteen, we find, “Benzene levels exceeded health benchmarks in one-third of the 87 homes studied.” So—let me do the math here—that means benzene levels were low in two-thirds of homes. How long do you think the paper’s editors considered the headline, “Gas stoves produce low levels of benzene in two-thirds of homes”?
We can look to the full study for additional details. The study does discuss other toxins emitted by gas stoves, but it studies only benzene and makes comparisons only with respect to that substance. Smoking tobacco also emits carbon monoxide, tar, arsenic, formaldehyde, and other toxins.
Here is the actual, highly qualified comparison to smoking from the study: “In 9 of the 33 cases (29%),a single gas burner on high or an oven set to 350° F raised kitchen benzene concentrations above the upper range of indoor benzene concentrations attributable to secondhand tobacco smoke (0.34−0.78 ppbv [parts per billion by volume]).”
The study cites other research to the effect that “any additional benzene exposure increases leukemia and lymphoma risk,” implying that even low levels of benzene can have some adverse health effects. Of course, the same can be said about exposure to radiation from the Sun or to radon gas, both of which Coloradans tend to get at higher rates.
Here’s a funny detail: The study uses the same “benchmark” for second-hand smoke as for “the median indoor benzene concentration measured in the US, Canada, Western Europe, Japan, South Korea, Hong Kong, and Australia,” in both cases 0.78 parts per billion. Indeed, that figure is the “upper range of indoor benzene concentrations attributable to secondhand tobacco smoke.” In other words, in terms of benzene exposure, second-hand smoke can be about as bad as just being in a typical room.
To me, here is the most remarkable thing about the study: In almost all cases, its organizers intentionally turned off available ventilation so as to maximize benzene accumulation. “We kept the range hood (a potential sink) off if one was present,” the study says.
In two whole houses, the study organizers did turn on the vent hoods. In one of those houses, even with the hood on, “benzene concentrations exceeded” California standards of 0.94 parts per billion. However, if you refer to supplementary figure S2, you’ll find that the hood did nevertheless substantially reduce benzene levels. Obviously more-powerful ventilation displaces more air. In the other house, the hood didn’t seem to have much effect—but benzene levels never surpassed the California bar whether the hood was on or off.
Unfortunately, “surveys show that ventilation hoods are used by residents only 20–40% of the time,” the study relates. Ventilation doesn’t work if it’s not present, not fully functional, and not turned on!
Here is another remarkable fact, via supplementary figure S10: Benzene emissions varied radically by cooking unit, from close to zero to over 70 micrograms per minute. Even within the same brand, emissions could vary widely. A related detail: The study covered both natural gas and propane stoves, even though propane tends to emit more benzene.
When we turn to the Colorado Sun, we find this variant of the comparison to smoking: “Gas stoves in Colorado produce toxic benzene levels worse than secondhand smoke, Stanford study finds.” I had to chuckle at the subhead, “Researchers don’t want families to panic . . .” Apparently unnecessarily panicking people is the job of news journalists! Only after you dig through the hyperbolic bullshit of the first seventeen paragraphs of reporter Michael Booth’s article do you reach the 9-in-33 qualifier.
Here, then, is the common-sense conclusion from the study (one consistent with previous findings): Cooking with a clean-burning gas stove with good ventilation is reasonably safe. Burning a crappy stove with poor or no ventilation is likely to result in unhealthy buildups of benzene. (I personally cook with electric and plan to continue doing so.)
Unfortunately, common sense seems to be in short supply among Colorado’s news journalists and headline writers, who too often favor cheap click-bait over context-rich facts.
Ari Armstrong writes regularly for Complete Colorado and is the author of books about Ayn Rand, Harry Potter, and classical liberalism. He can be reached at ari at ariarmstrong dot com.
