Requirements for Human Health Risk Assessments of Barnett Shale Gas Production and the Successful Challenge of a Plaintiff Expert

摘要

Overview. Several cases have resulted in Daubert challenge rulings that have affectedthe requirements for conducting site investigations and health assessments in litigioussituations that entail damage claims. This presentation will provide a summary of three“risk” assessments for plaintiffs, the flaws in the studies, and why the plaintiff expert’sopinions were barred from use in a recent plaintiff damage claim. Suggested guidelinesare provided tha, if followed, will in general allow experts to withstand Daubert challengesand complete credible human health risk assessments.Background/Objectives. Numerous law suits have been filed against the productioncompanies developing and producing natural gas using hydraulic fracturing from theBarnett Shale of central Texas. The author was retained by counsel to review some of theclaims and the health studies that were conducted to address public health concerns andtestified in a recent Daubert hearing. The specific objective of this work was to reviewthe “risk” assessments of plaintiff experts, the State of Texas and others and assesswhether they were scientifically founded.Approach/Activities. Recognized guidelines and procedures for conducting exposureassessments and human health risk assessments were referenced in developing criteriaand guidelines for Barnett Shale studies. These were used to review and critique the workof various agencies and experts. This paper presents a summary of the key elements andrequirements for sound human health risk assessments for the Barnett Shale and the basisfor a Daubert challenge of plaintiff expert opinions.Results/Lessons Learned. The various studies of the Barnett Shale document that gasproduction from the area has had an insignificant impact on the area in comparison toother sources of exposure. Shortcomings in regional studies are noted. The basic principlesfor human health risk assessments were not followed by some plaintiff experts,leading to a successful Daubert challenge that barred the opinions of a plaintiff expert ina recent case. Suggested guidelines are presented for defensible human health assessments.New disclosure regulatory requirements will result in future data to be assessedand the opportunity to apply the lessons learned.