Types of Data Used in Risk Assessment

Another important policy issue for risk assessment is the type of data that can be used in risk assessment. The context in which the risk assessment is used will often dictate what types of data may be used. In the regulatory context, agencies such as the U.S. EPA tend to make determinations based on the weight of evidence that considers aU available evidence, including human epidemiological and clinical data (when available), animal studies, and cellular and molecular assays (EPA 2005a). While the U.S. EPA states a preference for human data, it recognizes that 

Cancer risk assessments are also sometimes used in toxic tort and product liability litigation. In this context, courts express a much stronger preference for risk assessments based on human data and are more skeptical of animal studies. For example, the U.S. Supreme Court rejected the reliance of plaintiffs experts on animal studies showing that polychlorinated biphenyls (PCBs) can cause cancer, holding that the studies were so dissimilar to the human exposure and toxicity at issue in that case as to be without any value (GE 1997). This difference in the evidentiary approach of courts and agencies flows from the different institutional objectives (Allen 1996)  

Regulatory [agencies]. .. make prophylactic rules governing human exposure. This methodology results from the preventive perspective that the agencies adopt in order to reduce public exposure to harmful substances. The agencies threshold of proof is reasonably lower than that appropriate in tort law, which traditionally make[s] more particularized inquiries into cause and effect and requires a plaintiff to prove that it is more likely than not that another individual has caused him or her harm.  

In toxic tort and product liability litigation, the admissibility of new risk assessment methods and data must be approved by the trial judge before being presented to the jury. The U.S. Supreme Court announced a new standard for the admission of scientific data in 1993 in its Daubert decision (Daubert 1993). Under this new standard, federal judges must serve as a gatekeeper to ensure that scientific evidence is reliable and relevant, which includes an assessment of whether the evidence (i) has been empirically tested, (ii) has a known rate of error, (iii) has been peer-reviewed and published, and (iv) is generally accepted within the relevant scientific field. Many state courts have adopted a similar standard, although some still apply the earlier standard on admissibility (Frye 1923), which is whether the evidence is 

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