OUTCOME OF EARLY DEVELOPMENTAL PCB-EXPOSURE IN 42-MONTHS-OLD CHILDREN

Abstract

Background and Rationale Polychlorinated biphenyls (PCBs) a stable environmental con-taminant mixtures consisting of up to 209 congeners differing from each other by the number and position of chlorine atoms on the two basic benzene rings. Four marker congeners (IUPAC no 118, 138, 153, 180) are typically measured to quantify PCB-levels in biological and environmental material. PCBs are lipophilic, resistant to biodegradation, and cross the placenta thus exposing the foetus prenatally and, through nursing, postnatally the suckling baby, as well. PCBs are neurotoxic, particularly in a developmental context, but there is still controversy as to whether there is risk for adverse neurodevelopmental outcome at current environmental PCB-levels. In order to clarify this issue and in order to increase the statistical power for the detection of subtle effects an European coordinated cohort study was initiated covering rural, marine and urban environments in Denmark (Faroe Islands), the Netherlands (Groningen, Rotterdam) and Germany (Düsseldorf). Individual study reports have been pub-lished (Patandin et al., 1999; Steuerwald et al., 2000; Walkowiak et al., 2001), but results from the combined data set at 42 months of age have not yet been presented. Methods Healthy mother-infant pairs were recruited from local hospitals in Rotter-dam/Groningen (N = 418), the Faroe Islands (N = 182) and Düsseldorf (N = 171). 3 or 4 marker congeners were measured in maternal and/or cordblood, and in mother's milk taken at two weeks. At 42 months of age physical (height, weight, head circumference), neurological (Neurological Optimality according to Touwen), and mental development (Kaufman Achievement Battery for Children = K-ABC; Dutch and German Cohort only) were measured following a uniform protocol, and analysed for associations with neonatal PCB-exposure by means of multiple linear regression modelling. Results As for physical development no significant associations were found with neonatal PCB-exposure, but with postnatal PCBs in 42 months serum (t = −1.45; p < 0.1 for head cir-cumference, t = −2.46; p < 0.01 for height and t = −4.17, p < 0.001 for weight). No significant nor borderline associations were found for neurological development. As for mental devel-opment significant negative associations were found for K-ABC simultaneous processing (t = −2.24; p < 0.01) for PCBs in cordblood and borderline ones for postnatal intake, as well (t = −1.78; p < 0.10), but not for the sequential or composite scales. Conclusions As for physical development these data are primarily compatible with an inter-pretation in terms of growth-related PCB-dilution, although a negative impact of postnatal PCB-intake on growth cannot be fully excluded. As for mental development the findings are generally in line with previous reports emphasising the importance of prenatal PCB-exposure for neurodevelopmental adversity. Supported within EU Programmes (Contracts: EV5V-CT920 702, EVN4-CT96-0209).