What cooking does to the air in your kitchen

For years I framed air pollution as something outside.

Traffic, smog, the haze on a bad day.

I rarely mentioned the room where many of us make the most pollution ourselves.

The kitchen.

Cooking changes the air you breathe, sometimes by a lot.

The good news is that the research on how to manage that is clearer and more practical than the headlines suggest.

In this article, you’ll see what cooking adds to indoor air, what the evidence does and doesn’t show about the health effects, and the simple steps the studies say reduce exposure.

That should help you sort the part worth acting on from the part worth ignoring.

Cooking releases very small particles into the air. In a US apartment study, researchers measured ultrafine particle counts in the kitchen and living room peaking at 150,000 to 500,000 particles per cubic centimetre within about ten minutes of cooking ending [1].

The food itself produces these particles, whatever you cook on. Frying and high heat make more of them.

Gas adds something on top. A 2024 Stanford analysis measured emissions and concentrations in more than 100 homes and estimated that gas and propane stoves raise a person’s long-term nitrogen dioxide exposure by about 4.0 parts per billion on average, around 75% of the World Health Organization’s exposure guideline [2].

During use, short bursts of gas cooking often pushed kitchen nitrogen dioxide above both WHO and US Environmental Protection Agency benchmarks [2].

Nitrogen dioxide is a gas that irritates the airways. So two things happen while you cook. The food makes fine particles on any stove, and gas combustion adds nitrogen dioxide as well.

Smaller spaces concentrate it more. The same Stanford work found people in homes under about 75 square metres breathed roughly four times more long-term nitrogen dioxide from stoves than people in homes over about 280 square metres [2]. A small flat with a gas hob and no extractor fan sits near the worst case.

The clearest signal is in children’s airways. One analysis estimated that about 12.7% of current childhood asthma in the United States is statistically attributable to gas stove use, drawing on a pooled odds ratio of 1.34 from earlier studies [3]. The Stanford modelling separately linked long-term nitrogen dioxide from stoves to roughly 50,000 cases of childhood asthma [2].

Those are estimates built on observational data, which means they show associations and can’t prove cause and effect. Other researchers have argued the 12.7% figure overstates the link, because that kind of calculation rests on strong assumptions.

So cooking fumes and gas combustion are a real and measurable source of indoor air pollution, the childhood asthma association is genuine but contested in size, and the adult evidence is thinner.

None of that calls for alarm. It points to ventilation.

If you find pieces like this useful, you can get them free in your inbox each week.

The reassuring part is that the measures studied are cheap and simple.

In that same apartment study, opening the kitchen windows during and after cooking cut average indoor ultrafine particle levels by about 70%.

Running a kitchen range hood cut them by about 35%, and adding a portable air cleaner in the kitchen lowered them further [1].

Ventilation does most of the work.

The measures the research describes are ordinary ones. Running the extractor fan or range hood while cooking, including for low-heat meals that don’t visibly smoke. Opening a window where there is one. Using the back burners, which on many stoves sit closer to the hood and vent better. None of it costs much.

For anyone replacing a stove anyway, induction avoids combustion fumes, because the heat comes from the pan rather than a flame. That’s a long-term option, not something to rush.

The basics work here too. Ventilating while you cook is the single habit that addresses most of what the research raises.

Wishing you the best of health,

Adrian

This newsletter is free. If someone you know would find this useful, send it their way.

Share

Medical disclaimer

This article is general health information for adults, not personalised medical advice. It is not a substitute for consultation with your own doctor. The research described here is observational, which means it shows associations but cannot prove cause and effect. Individual results vary. If you have a medical condition, are pregnant, take medication, or are considering changes to your treatment or lifestyle, talk to your own doctor first.

1. Xiang J, Hao J, Austin E, Shirai J, Seto E. Characterization of cooking-related ultrafine particles in a US residence and impacts of various intervention strategies. Science of the Total Environment. 2021;798:149236. DOI: 10.1016/j.scitotenv.2021.149236. PMID: 34340070. https://doi.org/10.1016/j.scitotenv.2021.149236

2. Kashtan Y, Nicholson M, Finnegan CJ, et al. Nitrogen dioxide exposure, health outcomes, and associated demographic disparities due to gas and propane combustion by U.S. stoves. Science Advances. 2024;10(18):eadm8680. DOI: 10.1126/sciadv.adm8680. PMID: 38701214. https://doi.org/10.1126/sciadv.adm8680

3. Gruenwald T, Seals BA, Knibbs LD, Hosgood HD. Population attributable fraction of gas stoves and childhood asthma in the United States. International Journal of Environmental Research and Public Health. 2022;20(1):75. DOI: 10.3390/ijerph20010075. PMID: 36612391. https://doi.org/10.3390/ijerph20010075