Mortality study of a PFOA-exposed cohort in the mid-Ohio Valley

The C8 Science Panel previously conducted studies of perfluorooctanoic acid (PFOA) exposure in Ohio Valley residents, finding probable links with kidney and testicular cancers, raised cholesterol, ulcerative colitis, thyroid disease, and pre-eclampsia. Findings were largely based on a cohort of 32,254 persons with high PFOA exposure followed through 2011 for disease incidence. We have now followed this cohort through 2021 for mortality.

Deaths were ascertained via the National Death Index (NDI). We extended cumulative PFOA serum estimates from 2011 until 2021. We used internal comparisons via Cox regression models to analyze cause-specific mortality for 22 causes of death in relation to natural log transformed cumulative PFOA exposure (continuous and in quartiles) with a variety of lags, controlling for confounders. We also considered multiple cause of death.

There were 5709 deaths in the cohort through 2021. We found a positive significant trend (p < 0.05) in underlying cause of death analyses between the log cumulative serum level and brain cancer [HR 1.25 (1.05, 1.50)] and a suggestive but non-statistically significant association with bladder cancer [HR 1.17 (0.98, 1.39). . In stratified analysis, pancreatic cancer showed a positive significant trend among older participants (>72 years) [HR 1.23 (1.05, 1.43)]. No other causes showed marked positive trends, except for stroke among workers (13 % of total cohort).

PFOA exposure was significantly associated with mortality from brain cancer, and pancreatic cancer among older subjects. Pancreatic cancer has been associated with PFOA in animal studies, with equivocal evidence in other cohort studies. There was some suggestion of an increase of bladder cancer Caution is warranted due to multiple comparisons.