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A new study from Stanford University examined the presence of nitrogen dioxide in American homes, a pollutant found in gas stove emissions. Exposure to NO2 was found to be significantly worse in smaller homes because concentrations of the pollutant build up faster in more confined spaces. The modeling study showed that people living in residences smaller than 800 square feet were exposed to four times more nitrogen dioxide long-term than people in residences greater than 3,000 square feet. 

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Yannai Kashtan, a Ph.D. candidate at Stanford University and lead author on the study, said how much people used their stove, or how much gas they burned in total, was the most important factor determining NO2 exposure.

The team chose to focus on nitrogen dioxide, Kashtan said because igniting the flame on a gas stove causes the formation of nitrogen dioxide consistently, unlike other pollutants found in gas stove emissions such as benzene or carbon monoxide. 

Researchers determined NO2 exposure levels by collecting emissions samples from 100 homes in major U.S. cities including New York, Los Angeles, and Washington D.C. The team looked at variables like stove use frequency and intensity, range hood use and window ventilation, local climate, and occupant behavior to calculate exposure. They found short-term nitrogen dioxide exposure from typical gas stove use frequently exceeded benchmarks set by both the World Health Organization and the U.S. Environmental Protection Agency.  

According to the study, Black and Latino households were exposed to 20% more nitrogen dioxide, and Indigenous people were exposed to 60% more than the national average.

Kashtan said this likely comes from “historical and present-date discrimination affecting which demographic groups tend to live in larger versus smaller houses.”

Public health concerns

Using indoor air quality modeling and epidemiological risk parameters, the Stanford team estimated long-term nitrogen dioxide exposure from gas and propane stoves is responsible for approximately 50,000 current cases of pediatric asthma. They also found gas stoves may contribute to up to 19,000 adult deaths annually, with a societal cost of $250 billion.

Tom Phillips, researcher on indoor pollution and advisor on health-based building standards, agreed with the main findings of the Stanford study but was also concerned with ventilation rates and the complex mixture of particles and toxic pollutants from gas stoves and cooking itself. Phillips is associated with the southwestern Pennsylvania organization Reducing Outdoor Contaminants in Indoor Spaces, which has guidelines and tips for reducing indoor pollution. 

“Pittsburgh, because of its economic downturns, might have more maintenance problems in the appliances and ventilation systems,” he said. “[Pittsburgh] may have a lot of homes that don’t even have range hoods or they’re older range hoods that are noisy and people don’t use them.”

Phillips said using a range hood is one of the best ways to mitigate the negative effects of gas stove emissions in terms of cost and convenience. 

He said exposure varies from person to person, particularly those who cook often, or young children who may spend time in the kitchen with their caretakers. Based on previous studies, Phillips said women and unemployed people may be more impacted.

“Those kinds of human activity and socioeconomic differences,” he said, “are important when you not only characterize the risk, but when you decide how to best reduce it.”

Debate on restricting gas stoves

Kashtan said reducing risk could include updating codes for new construction, implementing policies that allow low-income groups and renters to switch out gas stoves for electric, and increasing subsidies for homeowners to do the same. 

“Without any hesitation, I can say we should be moving away from gas stoves. Burning gas is bad for your health,” he said. “I certainly am in favor of policies that make it easy and appealing for people to do the right thing for their health.”

Some, including Republicans in Congress, have pushed back against legislation attempting to reduce the use of gas stoves or ban them.

In a statement from the Pennsylvania Independent Oil and Gas Association, Dan Weaver,  President and Executive Director, said “Natural gas remains a preferred energy source for a number of uses throughout the U.S. … Limiting those choices by preventing new natural gas infrastructure or banning its use in some applications will result in higher energy costs for consumers without significant known and verified health benefits.”

The Hands Off Our Home Appliances Act would make it difficult for the Department of Energy to implement new energy efficiency standards for home appliances, including limiting gas stoves. Proponents of the bill said it aims to preserve the affordability and availability of household appliances.