Gas Piped Into Homes Contains Benzene and Other Risky Chemicals, Study Finds

The natural gas delivered to homes contains low concentrations of several chemicals linked to cancer, a new study found. Researchers also found inconsistent levels of odorants — substances that give natural gas its characteristic “rotten egg” smell — which could increase the risk of small leaks going undetected.

The study, which was published in the journal Environmental Science & Technology, adds to a growing body of research that links the delivery and use of natural gas to detrimental consequences for public health and the climate.

Most prior research has documented the pollutants present where oil and gas extraction takes place, but there are “fewer studies as you work your way down the supply chain,” said Drew Michanowicz, the lead author of the study, looking at “where we actually use it, in our homes.”

Over 16 months, researchers led by the Harvard T.H. Chan School of Public Health collected 234 samples of unburned natural gas from 69 homes in the Boston metropolitan area that received natural gas from three suppliers. They found 21 “air toxics” — an Environmental Protection Agency classification of hazardous pollutants known or suspected to cause cancer, birth defects or adverse environmental effects — including benzene, which was detected in 95 percent of the samples.

Short-term exposure to high levels of benzene in particular could lead to drowsiness, dizziness, headaches and irritation of the eyes and skin, according to the Centers for Disease Control and Prevention. Longer-term exposure can increase the risk of blood disorders and certain cancers like leukemia.