Serum PCB concentrations in residents of Calcasieu and Lafayette Parishes, Louisiana with comparison to the U.S. population

•The percentiles of serum total PCB concentrations were similar in both Parishes.•The adjusted GM of total serum PCBs was higher in residents in Lafayette than in Calcasieu Parish.•Serum total PCB levels in residents of both parishes increased linearly with age.•The PCB congener profiles were similar in residents of both parishes.

In 2002, a cross-sectional study designed to compare the serum dioxin toxic equivalent concentrations (TEQ) of a population-based sample of Calcasieu Parish, Louisiana residents, to Lafayette Parish was conducted. The mono-ortho polychlorinated biphenyls (PCBs) were measured in order to calculate the TEQ. We compared the sum of lipid adjusted serum concentrations of 27 PCB congeners (total PCBs) in residents of these two parishes and also by their demographic characteristics.The geometric means (GM) [standard errors (SE)] of the concentrations (ng g−1 lipids) of total PCBs in participants from Calcasieu Parish and Lafayette Parish were 154 (11.8) and 168.6 (20.8) (T-test p = 0.54), respectively. Various percentiles of the distribution of serum total PCB concentrations were similar in the two parishes. After adjusting by age and race in the ANCOVA regression model, the adjusted GM for the lipid adjusted total PCBs was statistically higher in the residents in Lafayette than in Calcasieu Parish regardless of age or race (P = 0.007). The adjusted GM of lipid adjusted total PCBs for African Americans was significantly higher than for Whites (p < 0.001). Serum total PCB levels in residents of both parishes increased linearly with age (P < 0.001). The congener profiles were similar in residents of both parishes. We also compared the GMs of a sum of 8 PCBs in Calcasieu and Lafayette Parish residents to those from a representative sample of the U.S. general population in 2001-2002 and they were not significantly different between parishes or between the parish data and the U.S. general population.