Domestic sources of natural gas used for cooking and heating in the United States may contain small amounts of toxic chemicals, some of which have been linked to cancer, according to a new study.
The new research, published in the journal Environmental Science and Technology, examined natural gas sources in 69 homes in the Greater Boston area between December 2019 and May 2021. Research led by the Harvard TH Chan School of Public Health found that it contains varying levels of 296 unique chemical compounds, 21 of which are identified as hazardous air pollutants at the federal level.
This chemical mixture may be spreading through your home even when you are not using the gas in any way.
“This study shows that gas appliances such as stoves and ovens can be a source of hazardous chemicals in our homes, even when we’re not using them. These chemicals are also likely to be found in leaky gas distribution systems in cities and in the supply chain,” said Jonathan Buonocore, Research Scientist at Harvard Chan C-CHANGE. .
One of the most worrisome chemicals found in household natural gas was benzene. Detected in 95 percent of samples taken, this chemical is found in tobacco smoke and car exhaust fumes, which are linked to an increased risk of developing leukemia and other blood diseases. Two other finds are xylene and toluene, toxic chemicals that can affect many organs from the gastrointestinal tract and lungs to the kidneys and heart.
The concentration of other chemicals is relatively small compared to methane, the main component of natural gas, but the levels are high enough to be of concern, the researchers say. They also noted how levels of harmful chemicals vary by region and time of year, with levels being highest during the colder winter months.
“When we talk about natural gas, we’re just talking about methane,” Drew Michanowicz, lead author and visiting scientist at the Harvard TH Chan School of Public Health, said at a press conference. “As pizza sauce is mostly tomato, natural gas is mostly methane. There are other trace substances in pizza sauce. You need salt, thyme, pepper.”
Another worrying finding in consumer-grade natural gas was the concentration of harmless but pungent odorants added to detect a leak in the event of a leak. In some samples, the researchers say they found enough odorants to be hard to smell in a small leak.
Drawing on the findings of the study, the scientists propose a series of policy changes, such as forcing gas pipeline companies to measure and report more detailed information on the composition of natural gas. Another proposal is to have government officials measure leaked, unburned natural gas in the ambient air to better understand the risk to the public.
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