Effects of occupational exposure to polychlorinated biphenyls on urinary metabolites of neurotransmitters: A cross-sectional and longitudinal perspective.

Polychlorinated biphenyls (PCBs) are chemicals that were used for industrial purposes and are known to induce various adverse health effects. They are also known to be neurotoxic and numerous targets within the central nervous system have been identified in previous studies. Specifically, the neurotransmitters dopamine (DA) and norepinephrine (NE) are influenced by PCBs as indicated in studies involving animals. However, limited evidence has been published documenting PCB induced changes in the neurotransmitter system in humans. In the present study, the authors examined the association between a higher PCB body burden following occupational exposure and possible changes in human neurotransmitter metabolites. Within a medical surveillance programme called HELPcB (Health Effects in High-Level Exposure to PCB) that monitors adverse health effects of occupational PCB exposure, urine samples were obtained (nT1=166; nT2=177 and nT3=141). The urinary concentrations of the metabolites homovanillic acid (HVA; for DA) and vanillylmandelic acid (VMA; for NE) were analysed. Blood samples were obtained by vena puncture in order to determine the internal exposure to PCBs with human biomonitoring. A cross-sectional analysis indicated a significant negative effect of PCB exposure on HVA and VMA. Longitudinally, an initially higher exposure to higher chlorinated PCBs was followed by constant reduced HVA level over three consecutive years. Exploratory analyses show different long-term effects for different PCBs according to their chlorination degree. A higher exposure with lower chlorinated PCBs leads to an increase of VMA and HVA. Conversely, a higher exposure to all PCBs results in a reduction of HVA. The authors concluded that these findings advances evidence obtained from past research, and identifies one potential pathomechanism in the central dopaminergic system of humans.

Authors: Putschögl FM, Gaum PM, Schettgen T, Kraus T, Gube M, Lang J. ;Full Source: International Journal of Hygiene and Environmental Health. 2015 Jul;218(5):452-60. doi: 10.1016/j.ijheh.2015.03.009. Epub 2015 Apr 1. ;