Cooks love their gadgets, from countertop slow cookers to instant-read thermometers. Now there is growing interest in magnetic induction cooktops – surfaces that cook much faster than conventional stoves, without lighting a flame or heating an electric coil.
Some of that attention is overdue: induction has long been popular in Europe and Asia, and it’s more energy efficient than standard stovetops. But recent studies have also raised concerns about indoor air emissions from gas stoves.
Inasmuch as environmental health researcher who works on housing and indoor air, I participated in studies that measurement of air pollution in homes and builds models to predict how interior sources contribute to air pollution in different types of homes. Here’s a perspective on how gas stoves can contribute to indoor air pollution and whether you should consider moving away from gas.
One of the major air pollutants commonly associated with the use of gas stoves is nitrogen dioxide, or NO2, which is a byproduct of fuel combustion. Exposure to nitrogen dioxide in homes has been associated with more severe asthma and increased use of rescue inhalers in children. This gas can also affect adults with asthma, and it contributes to both development and exacerbation of chronic obstructive pulmonary disease.
Nitrogen dioxide in homes comes from both outdoor air that seeps indoors and from indoor sources. Road traffic is the most important external source; unsurprisingly, the levels are higher close to major highways. Gas stoves are often the most important internal sourcewith a greater contribution from big burners that last longer.
The gas industry position is that gas stoves are a minor source of indoor air pollutants. This is true in some homes, especially with 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, especially for short-term “peak” exposures while cooking. For example, a study in Southern California showed that about half of homes exceeded a health standard based on the highest hour of nitrogen dioxide concentrations, almost entirely due to indoor emissions.
How can a gas stove contribute more to your exposure than an entire freeway full of vehicles? The answer is that outdoor pollution disperses over a large area, while indoor pollution concentrates in a small space.
The amount of indoor pollution you get from a gas stove is affected by the structure of your home, meaning indoor environmental exposures to NO2 are higher for some people than for others. People who live in large homes, who have functional range hoods that vent to the outside, and who have well-ventilated homes in general will be at less risk than those in smaller homes with poorer ventilation.
But even large homes can be affected by using a gas stove, especially since the air in the kitchen doesn’t immediately mix with cleaner air elsewhere in the house. Using a range hood when cooking or other ventilation strategies such as opening kitchen windows can significantly reduce concentrations.
Methane and Hazardous Air Pollutants
Nitrogen dioxide is not the only pollutant of concern from gas stoves. Some pollution with potential impacts on human health and the Earth’s climate occurs when stoves aren’t even working.
A 2022 study estimated that unused US gas stoves 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 may go unnoticed. Although gas distributors add an odorant to natural gas to ensure that people will smell leaks before there is a risk of an explosion, the odor may not be strong enough for residents to notice small leaks.
Some people also have a much stronger sense of smell than others. In particular, those who have lost their sense of smell – whether due to COVID-19 or other causes – may not smell even large leaks. A recent study revealed that 5% of houses had leaks that the owners had not detected that were large enough to require repairs.
This same study showed that a natural gas leak contained several hazardous air pollutants, including benzene, a carcinogen. Although measured concentrations of benzene have not reached levels of health concern, the presence of these hazardous air pollutants could be problematic in homes with large leaks and poor ventilation.
Reasons to change: health and climate
So if you live in a house with a gas stove, what should you do and when should you be worried? First, do what you can to improve ventilation, such as running a range hood that exhausts to the outdoors and opening kitchen windows while cooking. This will help, but it won’t eliminate exposures, especially for household members who are in the kitchen while cooking.
If you live in a smaller home or with a smaller enclosed kitchen, and if someone in your home has a respiratory condition like asthma or chronic obstructive pulmonary disease, exposures can still be a concern even with a good ventilation. Replacing a gas stove with a magnetic induction stove would eliminate this exposure while providing climate benefits.
There are several incentive programs to support gas stove switches, given their importance in slowing climate change. For example, the recently signed Inflation Reduction Act of 2022which includes many provisions to combat climate change, offers discounts for the purchase of high-efficiency electrical appliances such as stoves.
Dozens of U.S. cities have passed or are considering regulations that block natural gas connections in new homes after specific dates to accelerate the transition from fossil fuels. At the same time, at least 20 states have passed laws or regulations that ban natural gas bans.
Ditching gas stoves is especially important if you’re investing in home energy efficiency measures, whether you’re doing it to take advantage of incentives, reduce energy costs, or reduce your carbon footprint. Certain weatherization measures can reduce air leakage to the outside, which can in turn increase indoor air pollution concentrations if residents do not do so as well. improve kitchen ventilation.
In my opinion, even if you’re not determined to reduce your carbon footprint – or if you’re just looking for ways to cook pasta faster – the opportunity for cleaner air inside your home can be a strong motivation to make the change.