InsideClimateNews.org -- For years, the controversy over natural gas drilling has focused on the water and air quality problems linked to hydraulic fracturing, the process where chemicals are blasted deep underground to release tightly bound natural gas deposits.
But a new study reports that a set of chemicals called non-methane hydrocarbons, or NMHCs, is found in the air near drilling sites even when fracking isn't in progress.
According to a peer-reviewed study in the journal Human and Ecological Risk Assessment, more than 50 NMHCs were found near gas wells in rural Colorado, including 35 that affect the brain and nervous system. Some were detected at levels high enough to potentially harm children who are exposed to them before birth.
The authors say the source of the chemicals is likely a mix of the raw gas that is vented from the wells and emissions from industrial equipment used during the gas production process.
The paper cites two other recent studies on NMHCs near gas drilling sites in Colorado. But the new study was conducted over a longer period of time and tested for more chemicals than those studies did.
"To our knowledge, no study of this kind has been published to date," the authors wrote.
The researchers took weekly air samples at a site that's within one mile of 130 gas wells in Garfield County, Colo., with little other industry aside from natural gas production. They detected more than 50 chemicals between July 2010 and October 2011, including 44 with reported health effects. The highest concentrations were measured after new wells were drilled, but the concentrations did not increase after the wells were fracked.