Bladder cancer in perfluorooctanesulfonyl fluoride manufacturing workers.

PURPOSE

To determine whether bladder cancer is associated with exposure to perfluorooctane sulfonate (PFOS) in an occupational cohort.

METHODS

Incidence of bladder cancer was ascertained by postal questionnaire to all living current and former employees of the facility (N = 1895) and death certificates for deceased workers (N = 188). Exposure to PFOS was estimated with work history records and weighted with biological monitoring data. Standardized incidence ratios (SIRs) were estimated using U.S. population-based rates as a reference. Bladder cancer risk within the cohort was evaluated using Poisson regression by cumulative PFOS exposure.

RESULTS

Questionnaires were returned by 1,400 of the 1895 cohort members presumed alive. Eleven cases of primary bladder cancer were identified from the surveys (n = 6) and death certificates (n = 5). The SIRs were 1.28 (95% confidence interval [CI] = 0.64-2.29) for the entire cohort and 1.74 (95% CI = 0.64-3.79) for those ever working in a high exposed job. Compared with employees in the lowest cumulative exposure category, the relative risk of bladder cancer was 0.83 (95% CI = 0.15-4.65), 1.92 (95% CI = 0.30-12.06), and 1.52 (95% CI = 0.21-10.99).

CONCLUSIONS

The results offer little support for an association between bladder cancer and PFOS exposure, but the limited size of the population prohibits a conclusive exposure response analysis.