The Sixth Circuit last week upheld the dismissal of a plaintiff''s claim that benzene exposure caused her cancer. Pluck v. BP Oil Pipeline Co., No. 09-4572 (6th Cir., 5/12/11). The central issue was the exclusion of plaintiff's causation expert's opinion based on a "differential diagnosis" that failed to reliably rule in benzene exposure as a potential cause of plaintiff's cancer, and to rule out some other potential exposures.

This case arose from benzene contamination allegedly caused by gas-pipeline releases allegedly resulting in the seepage of gasoline into the surrounding soil and groundwater. Benzene, a component of gasoline, is a known carcinogen in sufficient doses under certain exposure circumstances, and is also ubiquitous in the ambient air and is a component or constituent of vehicle exhaust and cigarette smoke, said the court. Plaintiffs purchased a home in the area, and used well water to drink, wash, shower, and irrigate their yard and garden. In October, 1996, plaintiffs say they noticed a gasoline odor in their home and water, and benzene was first detected in the well on their property in the amount of 3.6 parts per billion (“ppb”). They began drinking bottled water in lieu of tap water, although they claim to have resumed drinking tap water upon the drilling of a new, deeper well. Between 1997 and May 2002, the new well tested negative for benzene twenty-two times.