Turn on the range hood while stir-frying and deep-frying, from the moment you light the stove until the cooking is done

Cost: For households already equipped with a range hood, the extra expense is just a bit more on the electricity bill. For those without one, buying and installing a unit costs several hundred to over a thousand dollars. The real challenge is remembering to turn it on every time you cook — don’t turn it off just because it makes noise.
In plain terms: Non-smoking Chinese women who rarely or never use a range hood while cooking face roughly twice the risk of developing lung cancer compared to those who use one regularly. Living in a kitchen with poor ventilation also raises this risk by about 50%, with the effect being most pronounced among households that burn coal.
Benefit: Ten case-control studies involving non-smoking Chinese women were pooled for analysis. In these studies, researchers compared lung cancer patients with healthy individuals, asking about past cooking habits. Overall, exposure to cooking fumes was linked to a 1.74-fold increase in lung cancer risk (95% CI 1.57–1.94). Four of these studies specifically looked at women who used no range hood while cooking; their risk was 2.11 times higher (95% CI 1.54–2.89). One Taiwanese study compared 1,302 non-smoking women with lung cancer to 1,302 healthy women, focusing on those with at least ten years of cooking experience. Women who used their range hood for more than two-thirds of those years had roughly half the risk of developing lung cancer compared to those who used it for less than a third of the time (OR 0.49, 95% CI 0.32–0.76). A Shanghai-based prospective study followed 71,000 non-smoking women from 1996 to 2009, identifying 429 cases of lung cancer. Women who reported living in a poorly ventilated kitchen had a 49% higher risk of lung cancer (HR 1.49, 95% CI 1.15–1.95). Those who had burned coal in such kitchens for over 20 years faced a 2.03-fold increase in risk (HR 2.03, 95% CI 1.35–3.05). No significant difference in risk was found between women who did and did not burn coal at all (HR 1.03, 95% CI 0.84–1.26), nor between those using different types of cooking oil.
Evidence grade: B
Sources:Xue Y, Jiang Y, Jin S, Li Y (2016). Association between cooking oil fume exposure and lung cancer among Chinese nonsmoking women: a meta-analysis. OncoTargets and Therapy, 9, 2987-2992. https://doi.org/10.2147/OTT.S100949；Chen TY, Fang YH, Chen HL, 等 (2020). Impact of cooking oil fume exposure and fume extractor use on lung cancer risk in non-smoking Han Chinese women. Scientific Reports, 10, 6774. https://doi.org/10.1038/s41598-020-63656-7；Kim C, Gao YT, Xiang YB, 等 (2015). Home kitchen ventilation, cooking fuels, and lung cancer risk in a prospective cohort of never smoking women in Shanghai, China. International Journal of Cancer, 136(3), 632-638. https://doi.org/10.1002/ijc.29020
Notes: There is some debate regarding these findings: the evidence supporting regular range hood use comes largely from case-control studies. Since participants recall past habits after being diagnosed with lung cancer, they may underreport how often they used their range hoods, potentially inflating the observed risk figures. The Shanghai study showed the greatest risk increase among households burning coal in poorly ventilated kitchens; it did not provide separate risk estimates for households using only gas. For this reason, the overall evidence grade is set at B, while the benefit is considered substantial based on the roughly twofold difference in risk. Women who regularly do the cooking at home are the primary beneficiaries of this measure; see section 29 of this chapter for more information on avoiding coal and wood for cooking and heating.