A recent study by researchers with The Endocrine Disruption Exchange (TEDX ) claims to have detected hazardous air pollutants (HAPs) known as non-methane hydrocarbons in the air near hydraulic fracturing sites in Colorado. Theo Colborn, et al., “An Exploratory Study of Air Quality near Natural Gas Operations,” Human and Ecological Risk Assessment, November 2012.

The researchers took weekly air samples at a site within one mile of 130 gas wells in Garfield County, Colorado. They detected more than 50 chemicals between July 2010 and October 2011, including 44 with reported health effects. All of the chemicals detected were at levels below the limits the federal government recommends to protect workers from dangerous chemicals, but the researchers argue that the risks of exposure may be different for people— including pregnant women, children and the elderly—who live near gas wells and are exposed 24 hours a day, seven days a week.

The highest chemical concentrations were apparently detected after new wells were drilled, and the concentrations did not increase after the wells were fractured. The study suggests that more research is needed on air pollution resulting from oil and gas drilling.