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 affected the requirements for conducting site investigations and health assessments in litigious situations 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’s opinions were barred from use in a recent plaintiff damage claim. Suggested guidelines are provided tha, if followed, will in general allow experts to withstand Daubert challenges and complete credible human health risk assessments. Background/Objectives. Numerous law suits have been filed against the production companies developing and producing natural gas using hydraulic fracturing from the Barnett Shale of central Texas. The author was retained by counsel to review some of the claims and the health studies that were conducted to address public health concerns and testified in a recent Daubert hearing. The specific objective of this work was to review the “risk” assessments of plaintiff experts, the State of Texas and others and assess whether they were scientifically founded. Approach/Activities. Recognized guidelines and procedures for conducting exposure assessments and human health risk assessments were referenced in developing criteria and guidelines for Barnett Shale studies. These were used to review and critique the work of various agencies and experts. This paper presents a summary of the key elements and requirements for sound human health risk assessments for the Barnett Shale and the basis for a Daubert challenge of plaintiff expert opinions. Results/Lessons Learned. The various studies of the Barnett Shale document that gas production from the area has had an insignificant impact on the area in comparison to other sources of exposure. Shortcomings in regional studies are noted. The basic principles for 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 in a recent case. Suggested guidelines are presented for defensible human health assessments. New disclosure regulatory requirements will result in future data to be assessed and the opportunity to apply the lessons learned.