Gas stoves in California homes are leaking cancer-causing benzene, researchers found in a new study published Thursday, though they say more research is needed to understand how many homes have leaks.
In the study, published in Environmental Science and Technology, researchers also estimated that over 4 tons of benzene per year are being leaked into the atmosphere from outdoor pipes that deliver the gas to buildings around California. And those emissions are unaccounted for by the state.
Eric Lebel is a co-author of the study and a senior scientist at PSE Healthy Energy, the nonprofit energy research and policy institute that conducted the research. He says that even low-level gas leaks can generate concentrations of benzene seven times California’s recommended exposure limits, and that these leaks can also affect outdoor air quality.
“We estimate that leaks from gas appliances and the pipes that feed them in cities can emit the same amount of benzene each year in the state of California as 60,000 passenger cars,” said Lebel.
The researchers collected samples of gas from 159 homes in different regions of California and measured to see which types of gases were being emitted into homes when stoves were off. They found at least 12 hazardous air pollutants in all the samples they tested, including benzene, toluene, ethylbenzene and xylene (together known as BTEX), all of which can have adverse health effects in humans with chronic exposure or acute exposure in larger amounts.
Of most concern to the researchers was benzene, a known carcinogen that can lead to leukemia and other cancers and blood disorders, according to the National Cancer Institute.
The finding could have major implications for indoor and outdoor air quality in California, which has the second highest level of residential natural gas use in the United States.
“What our science shows is that people in California are exposed to potentially hazardous levels of benzene from the gas that is piped into their homes,” said Drew Michanowicz, study co-author and senior scientist at PSE Healthy Energy. “We hope that policymakers will consider this data when they are making policy to ensure current and future policies are health-protective in light of this new research.”
Homes in the greater Los Angeles, North San Fernando Valley and Santa Clarita Valley areas had the highest benzene in gas levels. Leaks from stoves in these regions could emit enough benzene to significantly exceed the limit determined to be safe by the California Office of Environmental Health Hazards Assessment.
