“This is a pretty thin claim, in terms of a causal relationship between 4-methyl-imidazole and this form of cancer,” Judge Chen said.
“I have no idea whether the exposure level causes significant risks … and I don’t see any studies that have to do with humans.”
A U.S. District Court judge has dismissed with prejudice, a medical monitoring class action lawsuit that alleged consuming Diet Pepsi and Pepsi One soda products increases the risk of bronchioloalveolar cancer.
The named plaintiffs in the lawsuit relied on a report published by the National Toxicology Program (NTP) that concluded exposure to 4-methylimidazole (4-MEI) demonstrates an increased risk of cancer in mice. The same NTP report was also used as the basis for the California Office of Environmental Health Hazard Assessment’s (OEHHA) 2011 listing of 4-MEI as a Proposition 65 carcinogen.
However, in its analysis of NTP’s report, the Court determined the study implies that carcinogenic effects observed in mice may be species specific, since there was no similar increase in cancer in test rats.
The Court took note of NTP’s conclusion that the amounts of 4-MEI ingested from soft drinks may not be significant, finding that without significant exposure from Pepsi’s soft drink products, the plaintiffs could no establish a credible risk of cancer from typical soft drink consumption.
The Court was also unwilling to apply the findings of the NTP report to human exposure, noting the study recognized that “various species absorb, distribute, metabolize, and excrete” the substance differently. More importantly, the Court declined to conclude that humans would be exposed to 4-MEI at the same level as the test mice in the NTP study—the equivalent of approximately 300 cans of soda per day.
U.S. District Court Judge Edward Chen said that in medical-monitoring cases, the controlling case appears to be a California appeals court’s ruling in Potter v. Firestone Tire & Rubber Co., 6 Cal.4th 965, which found that to obtain medical monitoring, plaintiffs have to show that a chemical is significantly likely to cause serious
disease. They also must rely on the testimony of medical experts, he said.
“Here, there’s not much dispute that lung cancer is serious, but the other factors are problematic,” Judge Chen said. For example, consumers’ exposure to the chemical at issue, 4-methylimidazole, varies from person to person, and the toxicity level of the chemical isn’t clear with respect to bronchioloalveolar cancer, he said.
Judge Chen noted that he was unaware of any studies showing a significant risk of cancer in humans from exposure to 4-MEI.
Judge Chen wrote in his dismissal that it is “difficult to meet the constitutional standing requirement of pleading an ‘injury in fact’ that is ‘not conjectural or hypothetical’ when the only ‘injury’ is the alleged need for monitoring for a future disease.”
The lawsuit had been severed from a related case filed in the U.S. District Court in Southern California because it included personal injury claims and sought medical monitoring for consumers of Pepsi soda products. The Southern California case alleges that PepsiCo misled consumers when it failed to provide a Proposition 65 warning to consumers that its soda products contain 4-MEI.