title: Effects of occupational exposure to polychlorinated biphenyls on urinary metabolites of neurotransmitters: A cross-sectional and longitudinal perspective.
abstract: BACKGROUND
  Polychlorinated biphenyls (PCBs) are chemicals which 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.
  
  
  OBJECTIVE
  In the present study, we examined the association between a higher PCB body burden following occupational exposure and possible changes in human neurotransmitter metabolites.
  
  
  METHODS
  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 (n(T1) = 166; n(T2) = 177 and n(T3) = 141). The urinary concentrations of the metabolites homovanillic acid (HVA; for DA) and vanillylmandelic acid (VMA; for NE) were analyzed. Blood samples were obtained by vena puncture in order to determine the internal exposure to PCBs with human biomonitoring.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  This study, to our knowledge, is the first to document changes in neurotransmitter metabolites after occupational PCB exposure in humans. This finding advances evidence obtained from past research, and identifies one potential pathomechanism in the central dopaminergic system of humans.
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany. Electronic address: franziska.putschoegl@rwth-aachen.de.
authors: Franziska Maria
authors: FM
authors: Putschögl
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany.
authors: Petra Maria
authors: PM
authors: Gaum
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany.
authors: Thomas
authors: T
authors: Schettgen
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany.
authors: Thomas
authors: T
authors: Kraus
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany.
authors: Monika
authors: M
authors: Gube
authors: Institute of Occupational Medicine, RWTH Aachen University, Germany.
authors: Jessica
authors: J
authors: Lang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004298:Dopamine / Q000652:urine*; D004784:Environmental Monitoring; D005260:Female; D006719:Homovanillic Acid / Q000652:urine*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018377:Neurotransmitter Agents / Q000652:urine*; D009638:Norepinephrine / Q000652:urine; D016273:Occupational Exposure / Q000009:adverse effects*; D011078:Polychlorinated Biphenyls / Q000009:adverse effects*; D014642:Vanilmandelic Acid / Q000652:urine*; D055815:Young Adult
chemical_list: D018377:Neurotransmitter Agents; D014642:Vanilmandelic Acid; D011078:Polychlorinated Biphenyls; D004298:Dopamine; D009638:Norepinephrine; D006719:Homovanillic Acid
keywords: Homovanillic acid (HVA); Neurotransmitters; Occupational exposure; Polychlorinated biphenyls (PCBs); Vanillylmandelic acid (VMA)