Endocrine-Disrupting Chemicals and Oil and Natural Gas Operations: Potential Environmental Contamination and Recommendations to Assess Complex Environmental Mixtures

Christopher D. Kassotis, Donald E. Tillitt, Chung-Ho Lin, Jane A. McElroy, Susan C. Nagel

Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. While these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the approximately 1,000 chemicals used throughout the process, including many known or suspected endocrine-disrupting chemicals. We discuss the need for an endocrine component to health assessments for drilling-dense regions in the context of hormonal and anti-hormonal activities for chemicals used. We discuss the literature on 1) surface and ground water contamination by oil and gas extraction operations, and 2) potential human exposure, particularly in context of the total hormonal and anti-hormonal activities present in surface and ground water from natural and anthropogenic sources, with initial analytical results and critical knowledge gaps discussed. In light of the potential for environmental release of oil and gas chemicals that can disrupt hormone receptor systems, we recommend methods for assessing complex hormonally active environmental mixtures. We describe a need for an endocrine-centric component for overall health assessments and provide supporting information that using this may help explain reported adverse health trends as well as help develop recommendations for environmental impact assessments and monitoring programs.