Legal admissibility versus technical acceptability of expert judgments in risk assessment: An update

Many environmental and/or waste management regulations world require that risk assessment be performed to demonstrate compliance with those regulations. Given the litigious mentality prevalent in the United States, the divergence of ideas as to what is good environmental policy, and the controversial opinions generated by environmental issues, it is expected that most proposed solutions to environmental problems (and the decisions at their foundation) will face challenges and painstaking legal scrutiny. The merit of. any such challenge is usually weighed via a legal or quasi-legal proceeding In previous papers and presentations the authors have discussed, (1) using risk assessment to identify, formulate, defend and implement expert-legal opinions within the context of several specific examples illustrative of environmental problems or issues; (2) using risk assessment to support legal pronouncements made within the context of environmental management decision-making governed by specific statutory or regulatory schemes; and (3) how risk assessments must be performed so that the legal decisions or the expert opinions being supported become defensible within the. context of the specific statutory or regulatory legal scheme. In this paper the authors revisit the topics set forth above in light of recent pronouncements by various appellate courts which have modified the applicable legal standards. The authors will also compare the ever more divergent standards for legal admissibility and scientific acceptability of expert judgments in light of the most recent published legal precedents in which risk assessment has been at the core of an expert's opinion.