(CN) - An expert should have been allowed to testify that benzene exposure may have caused a former refrigeration technician to contract a rare type of leukemia, the 1st Circuit ruled.
Brian Milward claimed his work in the early 1970s with products containing benzene manufactured by Acuity Specialty Products Group and other defendants caused him to develop acute promyelocytic leukemia.
At trial in the District of Massachusetts, a federal judge ruled Dr. Martyn Smith's testimony that benzene can cause the disease was inadmissible. U.S. District Judge George O'Toole threw out the testimony partly because he found that there were other reasons Milward may have suffered from the disease.
But the 1st Circuit in Boston reversed the lower court's decision on Tuesday, ruling that it was up to the jury to decide if Smith's opinion supported Milward's negligence claims.
"Dr. Smith's opinion was based on an analysis in which he employed the 'same level of intellectual rigor' that he employs in his academic work," Judge Sandra Lynch wrote for the three-judge panel. "In excluding Dr. Smith's testimony, the District Court ... exceeded the scope of its discretion."
Lynch said there was no "sufficient basis" for ruling that Smith's opinion was inadmissible.
"The court's analysis repeatedly challenged the factual underpinnings of Dr. Smith's opinion, and took sides on questions that are currently the focus of extensive scientific research and debate - and on which reasonable scientists can clearly disagree," the ruling states. "In this, the court overstepped the authorized bounds of its role as gatekeeper."
The defendants' expert challenged published articles Smith used to support his testimony. But Lynch found it was not up to the court to decide if those studies were flawed.
"Where, as here, both experts' opinions are supported by evidence and sound scientific reasoning, the question of who is right is a question for the jury," Lynch said.
The judge noted that the case did not present a "situation in which the available epidemiological studies found that there is no causal link, or even one in which no cases of acute promyelocytic leukemia were found among benzene-exposed workers."
The judge added that those studies were inconclusive "because the rarity of acute promyelocytic leukemia makes it nearly impossible to perform a large enough study."
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