Right-wing bloggers and lobbyists have wasted no time attacking OSHA chief nominee Dr. David Michaels as a promoter of “junk science” who will lower the bar of scientific evidence needed to support OSHA standards-setting. Dr. Michaels explained his position in a written response to a written question submitted by Senator Johnny Isackson, R-Georgia.

You have written about Daubert v. Merell Dow Pharmaceuticals Inc., a 1993 Supreme Court case in which the Court ruled that judges could hold hearings without juries to determine whether expert testimony is relevant. Presumably, the Court’s intent was to preclude the possibility that a trial could be corrupted by hired experts who could sway a jury without proven scientific evidence. You have written that judges “have routinely misinterpreted and broadened the reach of Daubert” and concluded that “polluters and manufacturers of dangerous products are successfully using Daubert to keep juries from hearing scientific evidence or any other evidence against them.”

Please state your current views on Daubert and provide the (Senate Health, Education and Labor) Committee with examples of cases where judges “misinterpreted” the decision. Where do you draw the line between sound science and junk science?

I believe that the scientific evidence used in litigation should be, as the Daubert decision holds, “relevant and reliable.”

Daubert does not merely allow but actually requires judges to be gatekeepers, to determine relevance and reliability of scientific evidence. However, there is not convincing evidence that judges are more capable than juries in evaluating complex scientific evidence, and I am uncomfortable in the shift of decision-making power to judges from juries, since the right to trial by jury is one of the foundations of our legal system.

As I have written, there is evidence that Daubert has played a useful role in helping keep inaccurate or invalid science from being used in litigation. However, my concern with Daubert is that it forces judges, many of whom have no scientific background, to rule on issues beyond their expertise, and that this will result in the inconsistent application of justice. In this regard, I agree with the dissent of former Chief Justice Rehnquist who voiced concern about judges taking on the role of “amateur scientists.” In his partial dissent, Justice Rehnquist wrote: “Questions arise simply from reading this part of the Court’s opinion, and countless more questions will surely arise when hundreds of district judges try to apply its teaching to particular offers of expert testimony.”

One powerful example of this problem was identified by Dr. Jerome Kassirer, former editor of the New England Journal of Medicine, and Dr. Joe S. Cecil of the Federal Judicial Center, in an article published in the Journal of the American Medical Association. Kassirer and Cecil examined a group of similar cases involving Parlodel, a drug used to stop postpartum lactation. When women in several jurisdictions sued the manufacturer, claiming Parlodel was responsible for their strokes, seizures, or other adverse health effects, the same scientific evidence was considered by judges in these varying jurisdictions. In some cases judges refused to allow jurors to consider the opinion of scientific and medical experts who would have testified that Parlodel could cause these conditions. In other cases, judges allowed jurors to consider this same testimony. In one case, the judge decided to enlist the help of a panel of independent scientific experts. He arranged for the court to hire three prominent scientists from different disciplines and asked them to assess whether the plaintiff’s medical experts used scientifically reliable methodologies to form their opinions about causality, and to judge whether the techniques could be applied to the facts of the case. The three scientists did not come to the same conclusion.

In this example, I do not know which judges misinterpreted the scientific evidence, but they all cannot have been correct since they reached different conclusions concerning the same evidence.

The final component of this question illustrates the problem that Daubert attempts to address. I cannot provide a blanket statement that defines the line between “sound science” and “junk science.” I can provide specific examples of what I consider poorly done studies, or theories that are not supported by adequate scientific evidence, but studies that I respect may be dismissed by other scientists. As illustrated by the Parlodel example above, scientists often disagree: theories disputed in the past may be accepted today and dismissed in the future as research provides new evidence on the theory’s validity. If scientists have a difficult time agreeing on the meaning of certain scientific evidence, how can we expect judges, who often have little or no scientific training, to be the arbiters in disputes among scientists?