Jonathan Levy

Recent studies have raised concerns about indoor air emissions from gas stoves. Academic researchers and agencies such as the California Air Resources Board have reported that gas stoves can release hazardous air pollutants while they’re operating, and even when they’re turned off.

One of the main air pollutants commonly associated with using gas stoves is nitrogen dioxide, or NO2, which is a byproduct of fuel combustion. Nitrogen dioxide exposures in homes have been associated with more severe asthma and increased use of rescue inhalers in children. This gas can also affect asthmatic adults, and it contributes to both the development and exacerbation of chronic obstructive pulmonary disease.

Nitrogen dioxide in homes comes both from outdoor air that infiltrates indoors and from indoor sources. Road traffic is the most significant outdoor source; unsurprisingly, levels are higher close to major roadways. Gas stoves often are the most substantial indoor source, with a greater contribution from large burners that run longer.

The gas industry’s position is that gas stoves are a minor source of indoor air pollutants. This is true in some homes, especially with respect to exposures averaged over months or years.

But there are many homes in which gas stoves contribute more to indoor nitrogen dioxide levels than pollution from outdoor sources does, especially for short-term “peak” exposures during cooking time. For example, a study in Southern California showed that around half of homes exceeded a health standard based on the highest hour of nitrogen dioxide concentrations, almost entirely because of indoor emissions.

In Some Cases, Worse Than Cars

How can one gas stove contribute more to your exposure than an entire highway full of vehicles? The answer is that outdoor pollution disperses over a large area, while indoor pollution concentrates in a small space.

How much indoor pollution you get from a gas stove is affected by the structure of your home, which means that indoor environmental exposures to NO2 are higher for some people than for others. People who live in larger homes, have working range hoods that vent to the outdoors and have well-ventilated homes in general will be less exposed than those in smaller homes with poorer ventilation.

But even larger homes can be affected by gas stove usage, especially since the air in the kitchen does not immediately mix with cleaner air elsewhere in the home. Using a range hood when cooking, or other ventilation strategies such as opening kitchen windows, can bring down concentrations dramatically.

Nitrogen dioxide is not the only pollutant of concern from gas stoves. A 2022 study estimated that U.S. gas stoves not in use emit methane – a colorless, odorless gas that is the main component of natural gas – at a level that traps as much heat in the atmosphere as about 400,000 cars.

Some of these leaks can go undetected. Although gas distributors add an odorant to natural gas to ensure that people will smell leaks before there is an explosion risk, the smell may not be strong enough for residents to notice small leaks.

Leaks a Major Problem

Those who have lost their sense of smell – whether from COVID-19 or other causes – may not smell even large leaks. One recent study found that 5 percent of homes had leaks that owners had not detected that were large enough to require repair.

This same study showed that leaking natural gas contained multiple hazardous air pollutants, including benzene, a cancer-causing agent. While measured concentrations of benzene did not reach health thresholds of concern, the presence of these hazardous air pollutants could be problematic in homes with substantial leaks and poor ventilation.

So, if you live in a home with a gas stove, what should you do and when should you worry? First, do what you can to improve ventilation, such as running a range hood that vents to the outdoors and opening kitchen windows while cooking.

If you live in a smaller home or one with a smaller closed kitchen, and if someone in your home has a respiratory disease, exposures may still be concerning even with good ventilation. Swapping out a gas stove for a  magnetic induction cooktop, which cooks much faster than conventional stoves without igniting a flame or heating an electric coil, would eliminate this exposure while also providing climate benefits. The recently signed Inflation Reduction Act of 2022 offers rebates for the purchase of high-efficiency electric appliances such as stoves.

Dozens of U.S. cities have adopted or are considering regulations that bar natural gas hookups in new-construction homes after specified dates to speed a transition away from fossil fuels. At the same time, at least 20 states have adopted laws or regulations that prohibit bans on natural gas.

Moving away from gas stoves is especially important if you are investing in home energy efficiency measures. Some weatherization steps can reduce air leakage to the outdoors, which in turn can increase indoor air pollution concentrations if residents don’t also improve kitchen ventilation.

In my view, the opportunity to have cleaner air inside your home may be a strong motivator to make the switch.

Jonathan Levy is a professor and chair of the Department of Environmental Health at Boston University. His column is being reprinted under a Creative Commons license from The Conversation, a nonprofit news site affiliated with The Associated Press.

Is Your Gas Stove Bad for Your Health?

by Banker & Tradesman time to read: 4 min
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