Defendants Successful on Motion to Strike Plaintiff’s Expert’s Specific Causation Opinion 

United States District Court for the Northern District of California, July 11, 2022

Plaintiff, Frank Shelton, filed an asbestos-related lawsuit alleging his exposure to asbestos from various defendants’ products while he served in the Navy from approximately the mid-1960s to the early 1970s caused him to contract mesothelioma. During his service, plaintiff worked as a machinist mate while stationed aboard the USS Constellation, USS Repose, and USS Haleakala, where he regularly and routinely performed maintenance and repairs to various equipment in the machinery spaces to which he was assigned.   

Defendants filed a motion to strike the specific-causation opinions of plaintiff’s causation expert, Dr. Edwin Holstein. Defendants argued Dr. Holstein’s specific-causation opinions should be excluded because they were conclusory and not based on any sound scientific method, and, therefore, are irrelevant and unreliable.   

Federal Rule of Evidence 702 permits opinion testimony by an expert as long as the witness is qualified and, based upon that qualification, the witness’s opinion is relevant and reliable. An expert witness may be qualified by “knowledge, skill, experience, training, or education” as to the subject matter of the opinion. Fed. R. Evid. 702. The proponent of expert testimony has the burden of proving admissibility in accordance with Rule 702. Fed. R. Evid. 702, Advisory Committee Notes (2000 amendments). For scientific opinions, they must be based on scientifically valid principles. Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 589 (1993).   

In his report for this case, Dr. Holstein opined “because asbestos dust is so strongly associated with mesothelioma, proof of significant exposure to asbestos dust is proof of specific causation.” He also opined that “the total dose of asbestos that the patient breathes [] is the cause of the disease.” He explained “[m]esothelioma and []asbestos exhibit a dose-response relationship such that the more someone is exposed to asbestos, the greater their risk for the development of the[] cancer[]” and that “significant exposure to asbestos-containing dust from the use of products has been shown to contribute to cause [] mesothelioma.” Dr. Holstein further stated “there is no scientific evidence that a particular exposure or set of exposures, whether defined by time of exposure, brand of product, fiber type or any other characteristic, can be excluded from a causative role in the development of mesothelioma” and that “all significant exposures contribute to the causation” of mesothelioma.  

Lindstrom v. A-C Product Liability Trust, 424 F.3d 488 (6th Cir. 2005), is the seminal case for establishing proof of causation under maritime law. In Lindstrom, the Sixth Circuit held that to establish causation, a plaintiff must show, “for each defendant, that (1) he was exposed to defendant’s product, and (2) the product was a substantial factor in causing the injury.” 424 F.3d at 492. Evidence of exposure for a substantial period can provide a basis for the inference that the product was a substantial factor in causing plaintiff’s injury. Id. However, a mere showing that defendant’s product was present at plaintiff’s workplace is insufficient to establish causation. Id.  

Here, the court found Dr. Holstein’s “qualitative assessment” of the plaintiff’s exposure to be too generic. While Dr. Holstein stated he considered the “frequency, duration, and proximity” of the asbestos-containing products relative to the plaintiff’s work history, that statement was not based upon any identification or evaluation of the plaintiff’s exposure, frequency, or the regularity of the work performed on or around each of the defendants’ products. Dr. Holstein did not employ any method — much less one scientific or reliable — for determining whether plaintiff’s exposure to any of the defendants’ products was significant, and thus, could be a substantial factor in causing his mesothelioma.  

Since Dr. Holstein’s opinions lacked sufficient foundation upon which he could opine that the plaintiff’s actual interactions with the defendants’ products, including proximity and duration, were a possible substantial cause of the plaintiff’s mesothelioma, the court granted defendants’ motion to strike the specific-causation opinions of the plaintiff’s expert.  

Read the full decision here