Linear Predictors of Serum Concentrations of Polychlorinated Biphenyls (PCBs) in the Anniston Community Health Survey

Abstract

Polychlorinated biphenyls were produced in Anniston, Alabama, from 1932 to 1971. As part of the Anniston Community Health Survey, 765 residents who lived in close proximity to the former PCB production facility were interviewed and provided blood samples for analysis in 2005-2007. In this study, we examine demographic, behavioral, dietary, and occupational characteristics of Anniston survey participants as predictors of serum PCB concentrations. Most participants were female (70%), 54% White and 45% African-American, with a mean age of 55 years. Serum PCB concentrations varied widely between participants (range for sum of 35 PCBs: 0.11-170.4 ng/g wet weight; medians 5.76 ng/g wet weight among African-Americans and 2.24 ng/g wet weight among White participants). Factors associated with serum PCBs were examined using linear regression models. Statistically significant positive associations were observed between serum PCB concentrations and age, race, residential variables, current smoking, and local fish consumption, as was a negative association with education level. A small age by sex interaction was noted, indicating a steeper increase in PCB levels with age for women than for men. Other significant interaction terms indicated that the associations between PCB levels and having ever eaten locally raised livestock and local clay were much stronger among African-Americans than among White participants. Age and race were the most influential predictors of serum PCB levels. Regression results for most individual PCB congeners mirrored findings from analyses of SPCBs. However, an inverse association with current smoking was seen for PCBs 28 and 66, and positive associations were observed with female sex and BMI for less-chlorinated PCBs while inverse associations were seen for more highly chlorinated PCBs. Demographic variables and past consumption of locally produced foods were found to be the most important predictors of PCB concentrations for these Anniston residents.