ENDOCRINE DISRUPTING ACTIVITY OF NATURAL GAS DRILLING CHEMICALS AND IN SURFACE AND GROUND WATER IN A DRILLING DENSE AREA

The rapid rise in natural gas drilling operations has the potential to contaminate surface and groundwater with the more than 750 chemicals used in drilling and hydraulic fracturing processes. Many of these chemicals are known to be toxicants, carcinogens, and/or endocrine disruptors that have the potential to cause harm to humans and the environment.

Objective: Measure the estrogen receptor (ER) and androgen receptor (AR) agonist and antagonist activity of chemicals used in natural gas drilling and in surface and ground water in a drilling-dense region of Colorado from sites with known spills or other contamination from natural gas drilling operations.

Methods: 35 unique water samples were collected from five spill sites, two reference sites and the Colorado River in Garfield County, CO and subjected to solid phase extraction. Estrogen receptor (ER) and androgen receptor (AR) agonist and antagonist activity was measured in reconstituted samples using reporter gene assays in human cells.

Results: Water samples collected from reference sites in areas away from natural gas drilling exhibited the lowest levels of ER and AR activity, sites with known, documented natural gas drilling contamination exhibited significantly higher levels, and the Colorado River, the drainage basin for this region, exhibited a combination of the activity observed across sites. Twenty-four chemicals used in natural gas drilling operations were tested. Many of these exhibited significant anti-androgenic and anti-androgenic activity.

Implications: These results suggest spills associated with natural gas drilling may be contributing to endocrine disrupting activity in surface and ground water both at the site of contamination and in the Colorado River, the drainage basin for this area.