Polychlorinated biphenyls (PCBs) are still the most abundant pollutants in wildlife and humans. Hydroxylated PCB metabolites (OH-PCBs) are known to be formed in humans and wildlife. Studies in animals show that these metabolites cause endocrine-related toxicity. The health effects in humans have not yet been evaluated, especially the effect on the fetus and newborn. The aim of this study is to measure the levels of PCBs and OH-PCBs in maternal and cord blood samples in a population with background levels of PCBs. We analyzed 51 maternal and corresponding cord blood samples in the northern part of the Netherlands. The PCB concentrations in maternal plasma ranged from 2 to 293 ng/g lipid, and OH-PCB concentrations from nondetectable (ND) to 0.62 ng/g fresh weight. In cord plasma, PCB concentrations were 1–277 ng/g lipid, and OH-PCB concentrations, ND to 0.47 ng/g fresh weight. The cord versus maternal blood calculated ratio was 1.28 ± 0.56 for PCBs and 2.11 ± 1.33 for OH-PCBs, expressed per gram of lipid. When expressed per gram fresh weight, the ratios are 0.32 ± 0.15 and 0.53 ± 0.23 for PCBs and OH-PCBs, respectively. A significant correlation between the respective maternal and cord levels for both PCBs and OH-PCBs was found. Our results indicate that OH-PCBs and PCBs are transferred across the placenta to the fetus in concentrations resulting in levels of approximately 50 and 30%, respectively, of those in maternal plasma. More research in humans is needed to evaluate potential negative effects of these endocrine disruptors on the fetus.

No abstract

Polychlorinated biphenyls (PCBs) are environmental chemicals which are potentially toxic to the developing brain. Their hydroxylated metabolites (OH-PCBs) are suggested to be even more toxic. Knowledge about the health effects of prenatal OH-PCB exposure is limited. We aimed to determine whether prenatal background exposure to PCBs and OH-PCBs is associated with neurological functioning in 3-month-old boys and girls. In a Dutch observational cohort study, we measured 10 PCBs and 6 OH-PCBs in maternal blood samples of 98 pregnant women. We assessed their infants neurologically with Touwen examination at 3 months and calculated an Optimality Score (OS, range 0-53, low-high optimality). We calculated correlation coefficients between compound levels and OS. Subsequently, we tested whether levels were associated with specific clusters and whether levels differed between infants with "normal" (dysfunction on ≤1 cluster) and "non-optimal" development (dysfunction on ≥2 clusters). The mean OS was 48 (range 44-52). Higher exposure to PCB-146 correlated significantly with higher OS (r = 0.209; p = 0.039). In boys, higher exposure to 4-OH-PCB-107 correlated with lower OS (r = -0.305; p = 0.030). Higher exposure to 9 PCBs and the sum of all PCBs was associated with better visuomotor and/or better sensorimotor function. Infants classified as "non-optimal" (n = 36) had significantly lower prenatal exposure to 6 PCBs and the sum of all PCBs (p < 0.05) compared with infants classified as "normal" (n = 62). In conclusion, higher prenatal exposure to Dutch background PCB levels is associated with better neurological functioning in 3-month-old infants. Prenatal exposure to 4-OH-PCB-107 is associated with less optimal neurological functioning in boys.