Using a gas hob for cooking has been found to significantly increase indoor air pollution, potentially exposing individuals to serious health risks such as cancer, Parkinson’s disease, and heart disease, according to a recent investigation by consumer group Which?. The study, which involved volunteers from various households, revealed that cooking with gas hobs can generate higher levels of harmful pollutants than those typically found on some of the UK’s busiest roads.
In November 2024, Which? distributed air quality monitors to five volunteers—four using gas hobs and one with an induction hob—to measure the impact of everyday cooking on indoor air quality. The investigation focused on two of the most dangerous pollutants: nitrogen dioxide (NO2) and fine particulate matter (PM2.5). The volunteers, asked to conduct various cooking activities, were also instructed to use extractor hoods and keep windows and doors shut, except for one scenario where the kitchen was fully ventilated.
The results showed alarming levels of NO2, which more than doubled during certain cooking scenarios, especially when using multiple gas rings or engaging in “slow cooking” with one burner. The levels of NO2 persisted for hours after cooking, exposing those in open-plan homes to prolonged periods of high pollution. These findings suggest that even with ventilation, people may still face elevated concentrations of harmful air pollutants that exceed World Health Organization (WHO) guidelines.
NO2, a by-product of burning natural gas, is known to contribute to the development of asthma in children and can worsen respiratory conditions in both children and adults. PM2.5, tiny particles capable of penetrating deep into the lungs and bloodstream, have been linked to a range of serious health issues, including respiratory diseases, lung cancer, and increased risks of heart disease and Parkinson’s disease.
During the study, the average levels of NO2 recorded by the volunteer using an induction hob were consistent with background pollution, mainly from outdoor sources. In contrast, those using gas hobs experienced PM2.5 levels significantly above the WHO’s recommended limits. Some participants even recorded PM2.5 peaks exceeding 600 micrograms per cubic meter—more than 40 times the WHO’s 24-hour mean guidance of 15 micrograms per cubic meter.
The experiment revealed that indoor pollution from cooking could spread rapidly throughout the home. In some cases, NO2 and PM2.5 levels remained elevated for hours in adjacent rooms, suggesting that air quality issues may affect the entire household, even in separate areas of the home.
Experts have pointed out the risks of indoor air pollution, particularly for those who spend extended periods in close proximity to gas hobs, including in open-plan living spaces. While opening windows and using extractor fans can help reduce the buildup of pollutants, experts recommend considering the switch to induction cooking, especially if a hob needs to be replaced.
Emily Seymour, energy and sustainability editor at Which?, commented on the findings: “It’s shocking to think that something as routine as cooking dinner could be releasing harmful pollutants into our own homes. Our research shows that air pollution can spread quickly and linger long after cooking, potentially contributing to long-term health risks.”
Which? also conducted a public survey on air pollution, revealing that only 25% of people with gas hobs expressed concern about the potential health impacts, while 36% of respondents were worried about outdoor pollution entering through open windows.
The full extent of the impact of indoor pollutants on human health remains unclear, but experts agree that further research is needed to understand the long-term consequences of exposure to elevated levels of air pollution inside the home.
The Deltapoll survey conducted by Which? surveyed 2,002 UK adults between November 29 and December 2, 2024.
For anyone concerned about the risks, experts advise improving ventilation when cooking, considering the use of induction hobs, and taking steps to reduce exposure to harmful pollutants in the home.
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