Monitoring chlorinated persistent organic pollutants in adolescents in Flanders (Belgium): Concentrations, trends and dose-effect relationships (FLEHS II)

Background: In 2007, the second cycle of the Flemish human biomonitoring survey started, with a main focus on 14-15 year-old adolescents. Objectives: The main objectives were generating reference values for exposure markers, determining the pollution pressure in industrial hotspots and establishing dose-effect relationships between exposure to pollutants and hormone levels, sexual development, asthma and allergy, genotoxic and hematological markers. Methods: Geometric means with 95% confidence intervals (CI) were calculated for a reference population of 200 14-15 year-old adolescents. Stepwise multiple regression analyses with correction for confounders and covariates were performed to establish dose-effect relationships. Results: Geometric mean concentrations (with 95% Cl) of 49.6 (45.7, 53.8), 70.8 (63.6, 78.8) and 8.34 (7.76, 8.97) ng g(-1) lipid for the sum of PCB 138, 153 and 180, p,p'-DDE and HCB were respectively 23%, 26% and 60% lower than those obtained five years earlier. Geometric mean concentrations of 108 (101, 114) and 32.1 (30.1, 34.2) pg CALUX-BEQ g(-1) lipid were observed for the PCDD/Fs and dioxin-like PCBs, respectively. Multiple dose-effect relationships were observed between POPs and several effect markers, including positive (boys) and negative (girls) associations with data on sexual development and positive associations with asthma, animal allergy and free thyroxine (boys and girls). Conclusions: Our findings suggest that chlorinated POP concentrations are decreasing over time and that even relatively low concentrations are associated with biological effects. (C) 2014 Elsevier Ltd. All rights reserved.