Nearly one in 10 homes tested in the UK, Italy and the Netherlands showed benzene levels from gas cooker leaks that surpass safety limits, according to researchers. The cancer-causing chemical in natural gas poses risks akin to secondhand smoke indoors. The findings highlight potential indoor air pollution from slow leaks.
Researchers led by Drew Michanowicz at PSE Healthy Energy in Oakland, California, analyzed gas samples from cookers in 72 homes across the UK, the Netherlands and Italy. They found benzene concentrations in the gas were markedly higher than in the US: nine times higher in Italy, 37 times in the UK and 66 times in the Netherlands. Benzene, a known carcinogen linked to leukemia, immune suppression, anemia and excessive bleeding, was the primary concern among volatile organic compounds like toluene, ethylbenzene, xylene and hexane detected in the natural gas supply, including from North Sea sources and the Netherlands. In 35 homes, the team sealed kitchens to measure leak rates and estimated benzene exposure. Nine percent of these homes exceeded UK and European Union safety limits for the chemical, though researchers noted there may be no safe level and other sources could elevate totals further. “It’s akin to living with a smoker,” Michanowicz said. “Secondhand smoke creates a similar level of benzene indoors.” “This is just the benzene from the leaks,” he added. “We know there’re other sources of benzene, so actual benzene levels could be even higher.” Nicola Carslaw at the University of York, who was not involved, said natural gas leaks from cookers could be a significant benzene source depending on home behaviors and ventilation. Paul Monks at the University of Leicester called for moving away from gas stoves, citing evidence of indoor pollution risks and decarbonization benefits. European homes showed lower average leak rates than prior US measurements, but Michanowicz suggested broader testing could reveal higher averages. Most leaks were undetectable by smell, as human noses vary widely. Researchers recommended better ventilation, such as heat recovery systems, alongside induction hobs for safety and efficiency. The study appears in Environmental Research Letters (DOI: 10.1088/1748-9326/ae499f).
