Nancy Little sued The Budd Company in a Kansas federal court, alleging that Budd manufactured and sold railroad cars that caused her father’s mesothelioma. Little’s father worked for a railroad. For many years, he was exposed to pipe insulation that contained asbestos.

The Budd Company moved to exclude the testimony of two expert witnesses. Dr. Arnold Brody was offered as an expert in general causation. Dr. Barry Castleman was offered as an expert in industry knowledge of the risks of asbestos. Budd made no challenge to the testimony of the pathologist Little planned to call to prove specific causation.

The court denied the motion to exclude Dr. Brody’s testimony. The court generally allowed Dr. Castleman’s testimony about industry awareness but did not allow him to testify about the specific knowledge that Budd may or may not have had about the health risks associated with asbestos.

Dr. Brody’s Expert Opinion

Dr. Brody is a professor of pathology who has focused his research on how asbestos causes lung disease. Dr. Brody’s report examined tests of animals that inhaled asbestos and demonstrated that asbestos fibers inhaled by humans and by animals come to rest in the same part of the body. Dr. Brody also demonstrated that the cells affected by asbestos fibers are the same in both animals and humans.

Dr. Brody’s expert report explains how asbestos fibers cause mesothelioma. The report explains that repeated exposures to asbestos increase the likelihood of developing mesothelioma, and that each exposure above background level contributes to the development of the disease. Exposure to asbestos is the only known cause of mesothelioma.

Dr. Brody explained that no exposure can be excluded as a cause of mesothelioma. The consensus of scientific opinion is that no exposure above background levels is too low to induce mesothelioma.

Relevance of Dr. Brody’s Opinion

Budd did not challenge Dr. Brody’s qualifications to render an expert opinion. It instead contended that his opinion was irrelevant and unreliable. Budd’s relevance objection was based in part on the fact that Dr. Brody did not assess the impact of asbestos inhalation on Little’s father. However, since Dr. Brody was offered as an expert in general causation — that is, whether asbestos inhalation is capable of causing mesothelioma — his unfamiliarity with Little’s father did not affect the relevance of his opinion.

Budd also claimed that Dr. Brody’s opinions were not relevant because they were based on animal testing rather than human testing. Since Dr. Brody explained that animals and humans share the same cells that are affected by asbestos, and since researchers cannot ethically induce mesothelioma in human test subjects, animal testing was a reliable substitute for human testing. Budd’s objections went to the weight of Dr. Brody’s testimony rather than its admissibility.

Reliability of Dr. Brody’s Opinion

Budd claimed that Dr. Brody would testify that every inhalation of asbestos fibers above background exposure could cause mesothelioma. Budd argued that there is no known threshold of exposure that causes mesothelioma, rendering Dr. Brody’s opinion unreliable.

The court rejected Budd’s argument because it mischaracterized Dr. Brody’s opinion. Dr. Brody’s report explained that there is a dose-response relationship between asbestos and mesothelioma. The more asbestos a person inhales, the more likely it is that the person will acquire mesothelioma.

Once a person acquires mesothelioma, however, it is not possible to exclude any exposure as a causative factor, because each exposure contributes to the disease. No exposure above background levels is “too low” to contribute to the disease, so every exposure must be viewed as adding to the total dose of asbestos that caused a patient’s mesothelioma.

The court differentiated Dr. Brody’s testimony about general causation from testimony that a specific exposure to asbestos was a substantial cause of a specific individual’s mesothelioma. Since Dr. Brody’s testimony explained the disease process and did not address specific causation, and since his testimony was based on widely-accepted scientific research, the testimony was reliable and therefore admissible.

Little planned to call a pathologist to provide an expert opinion regarding specific causation. Budd complained that Dr. Brody’s testimony was therefore cumulative and unnecessary. Given that toxic tort defendants have spent years convincing courts that plaintiffs must prove both general and specific causation, it seems disingenuous to argue that it is cumulative to call separate experts to prove those separate facts. The court denied the motion to exclude Dr. Brody’s testimony.

Dr. Castleman’s Expert Opinion

Dr. Castleman has a Doctor of Science degree in Health Policy. He has conducted comprehensive research into asbestos as a public health problem. His report reveals that the railroad industry knew by the 1930s that asbestos was a lethal material and knew by the 1940s that inhaling asbestos could cause lung cancer.

Budd asserted a “state of the art” affirmative defense. It intended to prove that its railroad cars were as safe as they could have been at the time of their manufacture. Little proposed to call Dr. Castleman as a rebuttal witness to refute that defense.

Challenges to Dr. Castleman’s Testimony

The court rejected Budd’s argument that Dr. Castleman’s testimony would confuse the jury and waste time. Budd placed the state of the art in issue by raising the affirmative defense. Little was entitled to introduce evidence to counter that defense.

Budd argued that Dr. Castleman is not a medical doctor and is thus unqualified to interpret the literature upon which his opinion is based. However, Dr. Castleman did not propose to offer diagnostic or causation testimony. As an expert in public health, he was well qualified to explain “the historical development of knowledge regarding the health hazards of asbestos.” The court recognized that an expert does not necessarily need a medical degree to understand medical literature.

The court agreed with Budd that Dr. Castleman had no specific knowledge about what Budd actually knew about the health risks of asbestos when it built the railroad cars. The court cited cases suggesting that Dr. Castleman should not be allowed to testify about what Budd “should have known,” but since Dr. Castleman was allowed to testify about publicly available knowledge, his testimony would certainly allow the jury to infer that Budd should have known about the dangers of asbestos, even if Dr. Castleman cannot articulate that inference himself.

Finally, Budd argued that Dr. Castleman cannot establish that the medical articles upon which he relied were reliable. Dr. Castleman did not propose to vouch for the reliability of the studies. Published studies are nevertheless relevant to the state of knowledge about disease processes. Since medical studies are the type of data that experts in public health routinely rely upon in discussing the progress of medical knowledge, Dr. Castleman was entitled to use them as the basis for his expert opinion.