When you flick on your kitchen gas stove, you’re not just receiving a delivery of pure methane fresh from the bowels of Earth. According to a new study, the domestic gas supply used for cooking and heating in the US may also be laced with small amounts of toxic chemicals, some of which are linked to cancer.
New research, published in the journal Environmental Science & Technology, looked at the natural gas supply in 69 homes across the Greater Boston area between December 2019 through May 2021. The research, led by Harvard T.H. Chan School of Public Health, found it contained varying levels of 296 unique chemical compounds, 21 of which are federally designated as hazardous air pollutants.
This cocktail of chemicals could be making its way into your home even when you're not using any appliances.
“This study shows that gas appliances like stoves and ovens can be a source of hazardous chemicals in our homes even when we’re not using them. These same chemicals are also likely to be present in leaking gas distribution systems in cities and up the supply chain,” Jonathan Buonocore, a Research Scientist at Harvard Chan C-CHANGE, said in a statement.
One of the most worrying chemicals found in domestic gas was benzene. Detected in 95 percent of the samples, this chemical is found in tobacco smoke and car exhaust fumes that’s been linked to an increased risk of developing leukemia and other blood disorders.
Two other concerning finds were xylene and toluene, toxic chemicals that can impact many organs, from the gastrointestinal system and lungs to kidneys and heart.
The concentration of the other chemicals was relatively small compared to the prime ingredient of the natural gas – methane – but the researchers suggest the levels are high enough to raise concern. They also noted how levels of the harmful chemicals tend to vary by area and time of the year, with levels being highest in the colder winter months.
“When we talk about natural gas, we just talk about methane,” Drew Michanowicz, lead author and visiting scientist at the Harvard T.H. Chan School of Public Health, said in a press conference.
“Natural gas is mostly methane like pizza sauce is mostly tomatoes,” Michanowicz explained. “There’s other trace ingredients in pizza sauce. You need salt, oregano, pepper.”
Another worrying find was the concentration of odorants in consumer-grade natural gas, the harmless but pungent-smelling gas that’s added to natural gas to give it a giveaway smell in case of a leak. In some of the samples, the researchers say they found levels of odorants that would be hard to smell in a small leak.
Given their findings, the scientists on the project are suggesting a number 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 getting state authorities to measure leaked, unburned natural gas in ambient air to better understand the risk to the public.