Inhalation and Dietary PCB Exposures in Urban and Rural Cohorts of U.S. School Children and their Mothers

Abstract

PDS 62: Chemicals and metals: exposure and biomarkers, Johan Friso Foyer, Floor 1, August 28, 2019, 10:30 AM - 12:00 PM Background: Polychlorinated biphenyls (PCBs) are persistent man-made compounds that are carcinogenic, neurotoxic, immunotoxic, and act as endocrine disrupters. The AESOP Study is a rural and urban, community-based, prospective cohort study that assesses airborne and dietary exposures to all 209 PCBs and 72 OH-PCB metabolites in adolescent school children and their mothers. Methods: Exposures and risk factors were assessed through demographic, health, dietary (DHQ2), occupational and activity questionnaires and measurements of blood, urine, DNA, air, and food. We repeatedly evaluated indoor and outdoor air concentrations of PCBs from participants’ homes and from two rural and four urban schools over multiple seasons and years. The urban schools were located near a PCB-contaminated shipping canal off Lake Michigan. Air, blood and food samples were analyzed for PCBs using GC/MS-MS. Whole blood and surficial soil samples were analyzed for toxic metals using ICP-MS. Results: Concentrations of PCBs inside schools were 1−2 orders of magnitude higher than outdoors and were generally higher than in homes. Congener air profiles differed between schools and indicated the PCB sources as both legacy Aroclors and non-Aroclors from building materials. PCBs and OH-PCBs in the serum of the children showed enrichment of lower-chlorinated congeners compared to their mothers. Breast feeding was found to significantly decrease PCBs in mothers and increase PCBs in children who were breast fed. Modeling dietary intake and inhalation exposures (apportioning airborne exposures by time and location from activity logs) revealed that some children’s PCB inhalation exposure exceeded their exposure through diet, especially for the lower-chlorinated and more volatile PCBs. The AESOP study also showed that inhalation at school dominates children’s PCB inhalation exposures. Conclusions: To enhance children’s environmental health, air concentrations of PCBs in U.S. schools should be assessed in order to identify high-exposure locations and prioritize schools for replacement or repurposing.