Ulcerative Colitis and Perfluorooctanoic Acid (PFOA) in a Highly Exposed Population of Community Residents and Workers in the Mid-Ohio Valley

BACKGROUND Little is known about environmental determinants of autoimmune diseases. OBJECTIVES We studied autoimmune diseases in relation to level of exposure to perfluorooctanoic acid (PFOA), which was introduced in the late 1940s and is now ubiquitous in the serum of residents of industrialized countries. METHODS In 2008-2011 we interviewed 32,254 U.S. adults with high serum PFOA serum levels (median, 28 ng/mL) associated with drinking contaminated water near a chemical plant. Disease history was assessed retrospectively from 1952 or birth (if later than 1952) until interview. Self-reported history of autoimmune disease was validated via medical records. Cumulative exposure to PFOA was derived from estimates of annual mean serum PFOA levels during follow-up, which were based on plant emissions, residential and work history, and a fate-transport model. Cox regression models were used to estimate associations between quartiles of cumulative PFOA serum levels and the incidence of autoimmune diseases with ≥ 50 validated cases, including ulcerative colitis (n = 151), Crohn's disease (n = 96), rheumatoid arthritis (n = 346), insulin-dependent diabetes (presumed to be type 1) (n = 160), lupus (n = 75), and multiple sclerosis (n = 98). RESULTS The incidence of ulcerative colitis was significantly increased in association with PFOA exposure, with adjusted rate ratios by quartile of exposure of 1.00 (referent), 1.76 (95% CI: 1.04, 2.99), 2.63 (95% CI: 1.56, 4.43), and 2.86 (95% CI: 1.65, 4.96) (ptrend < 0.0001). A prospective analysis of ulcerative colitis diagnosed after the baseline 2005-2006 survey (n = 29 cases) suggested a positive but non-monotonic trend (ptrend = 0.21). DISCUSSION To our knowledge, this is the first study of associations between this common environmental exposure and autoimmune diseases in humans. We found evidence that PFOA is associated with ulcerative colitis.