A new study led by Boston University physiological ecologist Nathan Phillips reports a new level of pollution inside homes heated by natural gas. The gas contains pollutants including benzene, a known carcinogen, raising concerns that residents are breathing in small quantities of toxins around the clock.
According to reporting in The Boston Globe (June 11, 2026):
The study arrives amid a debate over the future of natural gas in Massachusetts, where policy makers are weighing the state’s climate goals against concerns about rising energy costs. Though regulators previously laid out a framework to transition away from natural gas, Governor Maura Healey has signaled an openness to bringing more of it into the state. Natural gas remains the dominant heating source for Massachusetts homes.
The researchers measured the concentration of methane, the primary component of natural gas, in the air of nearly 200 homes across Massachusetts and Rhode Island. Methane, which is considered safe to breathe at low concentrations, can be tested more cheaply and easily than the pollutants in the gas.
They found that more than 90 percent of residences that used gas had elevated levels of methane — even in newer builds — indicating the presence of leaks. The concentrations were so small that it can be difficult for homeowners to smell the gas.
A 2022 paper led by a researcher at the Harvard T.H. Chan School of Public Health and coauthored by Phillips found that unburned gas delivered to homes throughout the Greater Boston area contained a slew of hazardous air pollutants, including benzene, which the World Health Organization considers to be a carcinogen for which no safe level of exposure can be recommended…
When natural gas is burned, it releases pollutants such as formaldehyde, a known carcinogen, and nitrogen dioxide, a gas that can worsen respiratory issues. These appliances have been linked to premature deaths and pediatric asthma. Gas-powered furnaces and water heaters, which also combust fuel, are required to be vented outdoors.”