Joan E. Bertin

Health Risks Associated with Prenatal Metal Exposure

A symposium entitled Health Risks Associated with Prenatal Metal Exposure was held at the 33rd Annual Meeting of the Society of Toxicology (SOT) in Dallas, Texas. The symposium was cosponsored by the Metals and Reproductive and Developmental Specialty Sections of SOT and was designed to elaborate the health risks associated with in utero exposure to metals commonly found in the workplace and/or ambient environment on the mother and developing offspring. Epidemiological and toxicological evidence that demonstrates the health effects and underlying mechanisms associated with exposure to arsenic (As), lead (Pb), and methyl mercury (MeHg) were discussed, as well as the legal ramifications and personal implications associated with prenatal metal exposure. The following is a summary of each of the individual presentations.

Science, Law, and the Search for Truth in the Courtroom: Lessons from Daubert v. Merrell Dow

0 n June 28, 1993, the United States Supreme Court ruled on the admissibility of expert scientific opinion and evidence in federal court cases.’ The importance of the case can be measured by the interest it stimulated.z The scientific community turned out in particular force to register its views.3 At the heart of the controversy was a debate over the nature of scientific knowledge and its relation to law. More than any other Supreme Court case in recent memory, the amici seemed to view the Duubert case both as posing a potential challenge to basic scientific premises and as an opportunity to reclaim a lost prerogative to determine how science is applied in courts. The case raised questions about the kind of expert testimony that can be admitted in federal court cases, an issue that affects large numbers of cases that typically rely on expert opinions. Some obvious examples involve toxic torts, environmental remediation, and medical malpractice; less obvious examples include cases involving statistical analysis of employment patterns to discern discrimination, libel actions focusing on the truth of an assertion about the toxicity of a product, patent cases, and so forth. In these and other cases, courts must struggle with standards governing the admissibility and sufficiency of increasingly sophisticated scientific evidence. Animating the briefs filed by many mainstream scientific groups was the desire to use the case to address many of the perceived failings of the tort system: unpredictable verdicts, runaway juries, expensive discovery, and battles of the experts. Litigation over birth defects allegedly caused by the anti-nausea drug Bendectin, of which the Dulrbert case is one, fuels the charge that unwarranted claims forced a safe and useful product off the market.4 Even from this perspective,‘ however, the tortured history of the Bendectin litigation reflects the dilemma often posed by modern technology-that useful products may carry unknown risks, and that there is a need for compensation even in the absence of fault. With few exceptions, the scientific and medical umici assumed that the correct “answer” would emerge if judges and juries applied “good” scientific methods to the problem at hand. This assumption obscured the fundamental nature of the problem for courts confronting competing scientific claims: that science does not always provide dispositive answers to scientific questions, that adherence to valid scientific methodology can lead reputable experts in divergent directions, and that “truth” often cannot be ascertained with certainty? These issues appear in stark relief in cases, like Duubert, that involve reproductive and developmental injuries because of the need to prove causation, which can be elusive in such cases. To recover damages for a personal injury allegedly caused by the acts of another under either a negligence or a product (strict) liability theory, the plaintiff must prove that the defendant’s acts caused the injury. If someone fails to stop at a stop sign, hits another car, and injures its occupants, the negligent act is clearly the cause of the injuries. Many tort claims are characterized by this more or less direct cause-andeffect chain of events. Considerably greater difficulties arise when the cause-and-effect relationship is more difficult to discern, when the injury appears long after the alleged cause, or when the injury could have been produced by other causes.’ As the Daubert case revealed, the legal system is at a great disadvantage when resolution of disputes depends on the answers to scientific questions that themselves are the subject of dispute among scientists. This is not because judges and juries are not competent to sort out