Quantifying the U.S. Health Impacts of Gas Stoves

“I did not expect to see pollutant concentrations that exceed health standards in bedrooms an hour after using the gas stove and remain there for hours after the stove was turned off,” said Rob Jackson, a professor at the Doerr School of Sustainability at Stanford, lead author of the study. May 3 study in Scientific advances. Pollution caused by gas and propane stoves is not just a problem for cooks or people in the kitchen, she said. “It’s a problem for the whole family.”

Among other negative health effects, breathing high levels of nitrogen dioxide or NO₂It can intensify asthma attacks over time and has been linked to poorer lung development in children and premature death.

Although most of the exposure to NO₂ is caused by cars and trucks burning fossil fuels, researchers estimate that the mix of pollutants from gas and propane stoves in general may be responsible for up to 200,000 current cases of childhood asthma. A quarter of these can be attributed to nitrogen dioxide alone, according to the paper’s authors, who include scientists from the Central California Asthma Collaborative, PSE Healthy Energy, and the Harvard TH Chan School of Public Health.

“We found that the amount of gas you burn on your stove is by far the most important factor affecting your exposure. And then after that, do you have an effective range hood and do you use it?” said the study’s lead author, Yannai Kashtan, a doctoral student in Earth system sciences.

Little space for additional exhibition

Beyond cases of asthma, prolonged exposure to NO₂ in American homes with gas stoves is high enough to cause thousands of deaths each year, possibly up to 19,000 or 40% of the number of deaths related annually to secondhand smoke. This estimate is based on researchers’ new measurements and calculations of how much nitrogen dioxide people breathe at home from gas stoves and the best available data on deaths from long-term exposure to abroad NO₂which is regulated by the US Environmental Protection Agency.

The death toll estimate is approximate in part because it does not take into account the harmful effects of repeated exposure to extremely high levels of nitrogen dioxide over short periods of time, as occurs in homes with gas stoves. It also builds on previous studies on the health impacts of nitrogen dioxide found outdoors, where additional pollutants from vehicles and power plants are present.

Researchers used sensors to measure NO concentrations₂ in more than 100 homes of various sizes, designs and ventilation methods, before, during and after stove use. They incorporated these measurements and other data into a model powered by National Institutes of Standards and Technology (NIST) software known as CONTAM to simulate airflow, contaminant transport, and occupant exposure room by room in buildings. . This allowed them to estimate national averages and short-term exposures under a variety of realistic conditions and behaviors, and compare model results with measurements from their homes.

The results show that nationwide, typical use of a gas or propane stove increases exposure to nitrogen dioxide by about 4 parts per billion, on average over a year.. This represents three-quarters of the level of nitrogen dioxide exposure that the World Health Organization recognizes as unsafe in outdoor air. “That excludes all outside sources combined, so it’s much more likely that the limit will be exceeded,” Kashtan said.

Understand how gas stoves affect health

The study is the latest in a series from Jackson’s group at Stanford looking at indoor air pollution caused by gas stoves. Previous studies have documented the rate at which gas stoves emit other pollutants, including the greenhouse gas methane and the carcinogen benzene. But to understand the implications of stove emissions for human health, researchers needed to discover how many pollutants spread through a home, accumulate, and eventually dissipate. “We’re moving from measuring how much pollution comes from stoves to how much pollution people are actually breathing,” said Jackson, the Michelle and Kevin Douglas Provostial Professor of Earth System Sciences.

With any fuel source, particulate contamination can increase when cooking food in a hot pan. However, new research confirms that foods emit little or no nitrogen dioxide while cooking, and electric stoves do not produce NO.₂. “It’s the fuel, not the food,” Jackson said. “Electric stoves do not emit nitrogen dioxide or benzene. If you own a gas or propane stove, you should reduce exposure to contaminants through ventilation.”

House size matters

Even in larger homes, nitrogen dioxide concentrations routinely rose to unhealthy levels during and after cooking, even if a range hood was on and venting the air outdoors. But people living in homes smaller than 800 square feet (about the size of a small two-bedroom apartment) are exposed to twice as much nitrogen dioxide over the course of a year compared to the national average, and four times as much compared to those who live in the largest homes, over 3,000 square feet.

Because home size makes such a difference, there are also differences in exposure across racial, ethnic, and income groups. Compared to the national average, researchers found long-term NO₂ Exposure is 60% higher among American Indian and Alaska Native households, and 20% higher among Black, Hispanic, or Latino households. This exposure to indoor air pollution from gas stoves compounds the fact that exposure to outdoor sources of nitrogen dioxide pollution, such as vehicle exhaust, also tends to be higher among people in poorer communities. , often minority.

“People in poorer communities don’t always have the luxury of replacing their appliances, or maybe they rent them and can’t replace them because they don’t own them,” Jackson said. “People who live in smaller homes also breathe in more pollution from the same stove use.”

This research was supported by HT, LLC.