title: A cohort incidence study of workers exposed to perfluorooctanoic acid (PFOA).
abstract: OBJECTIVE
  Determine if perfluorooctanoic acid (PFOA) is associated with an incident disease in an occupational cohort.
  
  
  METHODS
  We interviewed 3713 workers or their next of kin in 2008-2011, and sought medical records for self-reported disease. These workers were a subset of a previously studied cohort of 32,254 community residents and workers. We estimated historical PFOA serum levels via a job-exposure matrix based on over 2000 serum measurements. Non-occupational exposure from drinking water was also estimated. Lifetime serum cumulative dose (combining occupational and non-occupational exposure) was our exposure metric. We studied 17 disease outcomes with more than 20 validated cases.
  
  
  RESULTS
  The median measured serum level was 113 ng/mL in 2005 (n=1881), compared with 4 ng/mL in the US. Ulcerative colitis (10-year lag) showed a significant trend (p≤0.05) with increasing dose (quartile rate ratios (RRs)=1.00, 3.00, 3.26, 6.57, n=28, p for trend=0.05), similar to earlier findings in the community study. Rheumatoid arthritis (no lag) showed a positive trend in a categorical trend test (RRs=1.00, 2.11, 4.08, 4.45, n=23, p for trend=0.04). Positive non-significant trends were also observed for prostate cancer, non-hepatitis liver disease and male hypothyroidism, which have been implicated in other studies. A significant negative trend was found for bladder cancer and asthma with medication. No marked trends were seen for high cholesterol, which had been seen in the community study.
  
  
  CONCLUSIONS
  Ulcerative colitis and rheumatoid arthritis were positively linked to PFOA exposure among workers. Data were limited by small numbers, under-representation of hard-to-trace decedents and few low-exposed referents.
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Steenland
authors.affiliation: Department of Biostatistics, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Liping
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA.
authors.forename: Andrea
authors.initials: A
authors.lastname: Winquist
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000139:chemically induced*; D002210:Caprylates / Q000009:adverse effects* / Q000097:blood; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000139:chemically induced*; D005466:Fluorocarbons / Q000009:adverse effects* / Q000097:blood; D006801:Humans; D006937:Hypercholesterolemia / Q000209:etiology; D007037:Hypothyroidism / Q000139:chemically induced; D015994:Incidence; D008107:Liver Diseases / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D011471:Prostatic Neoplasms / Q000139:chemically induced; D014874:Water Pollutants, Chemical / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D002210:Caprylates; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; C023036:perfluorooctanoic acid