Cooking, stove use among potential household health hazards for women

Key takeaways:

• Women as well as children are impacted by pollutants caused by cooking stoves.
• Experts recommend not using a gas stove or one that requires combustibles to cook.
• Proper ventilation can lower these risks.

The respiratory and health impacts of cooking — a ubiquitous household chore often assumed by women — may be underappreciated, with fumes from gas and propane stoves a leading source of asthma, data show.

In this second installment of a two-part series on household hazards, Healio’s Women in Allergy explores potential risks women may face associated with cooking exposures. The first part of the series focused on the effects cleaning products may have on women’s health.

According to a Cookpad/Gallup survey of global home-cooking trends, women cooked more than twice as many meals as men based on 2022 data. Globally, the gender gap in cooking frequency is 4.7 meals per week, although it varies greatly by location. The widest gender gaps are seen in Ethiopia, Egypt and Nepal and the narrowest in Spain, the U.K. and France. In the U.S., women cook on average about two more meals per week than men. The only country where men cook more than women is Italy.

Even while assessing factors that predict the frequency of cooking, gender — only then followed by location — was found to be the most significant predictor of cooking. Regardless of employment status, marital status or age, a significant gender gap persisted. However, the gender gap shrinks when it comes to education. Women with 4 years of education beyond high school see fewer disparities, according to the report.

Cooking hazards

As common as cooking indoors may be, the fact that it may expose those at home to harmful pollutants may not be well acknowledged.

A study published earlier this year in Science Advances, conducted by Kashtan and colleagues, showed that exposure to nitrogen dioxide (NO₂) from gas and propane cooking stoves may be responsible for thousands of cases of asthma across the U.S.

The researchers estimated that average homes across the U.S. experience a median increase of long-term NO₂ exposure due to stove use at 4 (95% CI, 2.4-6.1) ppb by volume, or 75% of the WHO’s recommended guideline for exposure. Those who used their stoves at home approximately 110 days per year — landing them in the 95th percentile of those who use stoves — experienced exposures surpassing WHO’s recommended 200 µg/m³ for 1 hour of indoor exposure.

With women generally cooking twice as often as men, this can lead to a substantial overexposure to NO₂ and other pollutants.
“Women are both exposed to cleaning products, which can have negative impacts on your immune system and your respiratory health and then they're also being exposed to the cooking fumes from gas stoves,” Mary Margaret Johnson, MD, PhD, principal research scientist at Harvard T.H. Chan School of Public Health, told Healio. “That's compounding the health impacts.”

According to Kashtan and colleagues, gas stoves may be linked to 19,000 deaths among U.S. adults each year. They also estimated that long-term NO₂ exposure is responsible for 50,000 current cases of pediatric asthma, and that the total number of current pediatric asthma cases likely linked gas and propane stoves may reach 200,000 — a number they say corresponds to about $1 billion in societal costs each year.

“It's another example of a disparity that needs to be addressed because not only are the women potentially impacted, but also their offspring,” Johnson said.

Pollution caused by fumes from cooking can also cause irritation and inflammation as well as DNA damage in people with asthma, according to a study by Laursen and colleagues. Participants reported increased symptoms after being exposed to emissions from cooking, such as eye irritation, nose irritation, headache and nausea, with women reporting more severe symptoms than men.

Another major factor of illness is the type of fuel used in cookstoves, especially in developing countries where solid fuels such as wood, crop wastes and charcoal are used. The WHO estimates that household air pollution contributed to approximately 3.2 million deaths per year in 2020, including 237,000 children aged younger than 5 years. They also note that women and children take on the greatest household air pollution burdens as they are typically responsible for cooking and collecting stove fuels. The WHO data also reflect a global disparity in this issue, as they estimate only 14% of people from urban areas use polluting fuels, compared with 49% of those residing in rural areas.

“There's a whole issue in lower income countries of cooking stoves,” Johnson said. “That’s a situation in which women are being exposed to a lot more respiratory pollution than men. They don’t use clean cooking fuel, and so the health outcomes are even worse.”

Guidelines, recommendations

To minimize the health risks of cooking, Johnson said it’s best not to use a gas stove at all or one that uses combustibles.

“If you have a choice, don’t have a gas stove,” she said. “Use an electric stove or a stovetop. However, if you do have a gas stove, you might pick up an air monitor so you can monitor the air quality.”

Efforts are also underway to provide fuel conservation education for those living in lower-income countries that have less access to clean energy resources.

For instance, in a study by Williams and colleagues, conducted in Peru, participants were taught fuel conservation strategies to promote clean cooking, such as by using pressure cookers and heating water in the sun. The results showed that participants’ average daily energy consumption decreased as their conservation efforts increased.

Having a ventilation system also helps, according to Johnson. For instance, data from Kashtan and colleagues showed that using a venting hood or even opening windows while cooking can reduce pollutant exposure.

Cooking for shorter periods of time is also beneficial, Johnson said.

“Whatever you can do to reduce the amount of time that you’re spending at the stove would be helpful,” Johnson said.

References:

• Kashtan Y, et al. Sci Adv. 2024;doi:10.1126/sciadv.adm8680.
• A global analysis of cooking around the world. https://www.gallup.com/analytics/512897/global-cooking-research.aspx. Published 2023. Accessed Aug. 9, 2024.
• Household air pollution. https://www.who.int/news-room/fact-sheets/detail/household-air-pollution-and-health. Published Dec. 15, 2023. Accessed Aug. 9, 2024.
• Laursen KR, et al. Part Fibre Toxicol. 2023;doi:10.1186/s12989-023-00537-7.
• Williams KN, et al. Environ Int. 2023;doi:10.1016/j.envint.2023.108223.

For more information:

Mary Margaret Johnson, MD, PhD, can be reached at mjohnson@hsph.harvard.edu.