TOWARD A ROBUST RISK ASSESSMENT PARADIGM FOR THE ENVIRONMENTAL IMPACTS OF SHALE GAS DEVELOPMENT

Horizontal drilling and hydraulic fracturing have significantly enhanced US domestic energy production since 2005. Nonetheless, environmental concerns such as compromised drinking-water and air quality near shale gas development zones have led to significant public and political debate. Much attention is focused on the fate of anthropogenic contamination (e.g., hydraulic fracturing fluids) without considering how natural fluids may impact health. This oversight results from a dearth of transdisciplinary research groups capable of fully appreciating the geological, occupational, and industrial complexities that determine exposure to anthropogenic and other harmful natural fluids. Thus, future efforts to evaluate the environmental impacts of shale gas development must reduce uncertainties in the source of contaminants (e.g., natural vs. anthropogenic sources for methane in groundwater), improve the toxicological assessment of complex natural geofluids (e.g., metal- and gas-rich brackish waters), and create robust long-term epidemiological studies, amongst others. Risk is a function of exposure and hazard (dose-response relationship), while each of the aforementioned factors is a critical component of the risk assessment paradigm. Here, we will develop and review the critical expertise (e.g., geoscientists, hydrogeologists, medical geologists, toxicologists, occupational medical clinicians, and epidemiologists) necessary for an accurate assessment of human and ecological risks stemming from shale gas development.