Cohort Mortality Study of Workers Exposed to Perfluorooctanoic Acid

Abstract

Perfluorooctanoic acid (PFOA) is persistent in the human body; the general population has serum levels of approximately 4 ng/mL. It causes tumors of the liver, pancreas, and testicles in rodents. The authors studied the mortality of 5,791 workers exposed to PFOA at a DuPont chemical plant in West Virginia, using a newly developed job exposure matrix based on serum data for 1,308 workers from 1979-2004. The estimated average serum PFOA level was 350 ng/mL. The authors used 2 referent groups: other DuPont workers in the region and the US population. In comparison with other DuPont workers, cause-specific mortality was elevated for mesothelioma (standardized mortality ratio (SMR) = 2.85, 95% confidence interval (CI): 1.05, 6.20), diabetes mellitus (SMR = 1.90, 95% CI: 1.35, 2.61), and chronic renal disease (SMR = 3.11, 95% CI: 1.66, 5.32). Significant positive exposure-response trends occurred for both malignant and nonmalignant renal disease (12 and 13 deaths, respectively). PFOA is concentrated in the kidneys of rodents, and there are prior findings of elevated kidney cancer in this cohort. Multiple-cause mortality analyses tended to support the results of underlying-cause analyses. No exposure-response trend was seen for diabetes or heart disease mortality. In conclusion, the authors found evidence of positive exposure-response trends for malignant and nonmalignant renal disease. These results were limited by small numbers and restriction to mortality data, which are of limited relevance for several nonfatal outcomes of a priori interest.

Per- and polyfluorinated substances (PFASs): Environmental challenges

“…serum PFOA concentration 350 ng/mL; general population ~4 ng/nL) reported an increase of malignant and non-malignant renal diseases, but on limited numbers, and no exposure/response trend for diabetes or ischemic heart disease [278]. The most recent evaluation of mortality and cancer incidence in APFO production workers found no association between APFO exposure and risk of prostate and kidney cancer, diabetes and stroke [279].…”

Mortality and cancer incidence in ammonium perfluorooctanoate production workers

“…A cohort mortality study of the DuPont Washington Works (Parkersburg, West Virginia, USA) polytetrafluoroethylene (PTFE) plant, where APFO was used as a processing aid, reported chronic renal disease and kidney cancer associated with increasing occupational exposure to PFOA 12. Tetrafluoroethylene (TFE) exposure was highly correlated with PFOA exposure, and TFE is a kidney carcinogen in rats 13.…”

Extensive literature search and provision of summaries of studies related to the oral toxicity of perfluoroalkylated substances (PFASs), their precursors and potential replacements in experimental animals and humans. Area 1: Data on toxicokinetics (absorption, distribution, metabolism, excretion) in in vitro studies, experimental animals and humans. Area 2: Data on toxicity in experimental animals. Area 3: Data on observations in humans

“…65-4.96). No trend was observed for any other autoimmune disease (Steenland and Woskie 2012). Dong et al (2013) reported a significant difference in serum levels of PFOA between children with (n = 231) (mean = 1.5 ± 1.3 ng/mL) or without (n = 225) (mean = 1.0 ± 1.1 ng/mL) asthma, and a significant dose-response relationship (AOR in quartile 4 [> 2.2 ng/mL] was 4.05, 95 % CI = 2.21-7.42).…”

“…Data for PFNA, PFHxS and PFOS were also presented in the study (see Sections 8.3,16.3 and 18.3,respectively) (Power et al, 2013). Steenland and Woskie (2012) reported that cause-specific mortality in an occupationally exposed cohort of 1 308 workers, was significantly increased for mesothelioma (when compared with the US population). The overall SMR was 2.85 (95 % CI = 1.…”