Fetal Exposure to PCBs and Their Hydroxylated Metabolites in a Dutch Cohort

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

Polychlorinated and hydroxypolychlorinated biphenyls:influence on child neurological and endocrine development

PCB’s zijn chemische stoffen die tot in de jaren zeventig op grote schaal werden toegepast in onder meer plastics, brandwerende en warmtegeleidende materialen. Veertig jaar geleden werd het gebruik ervan verboden, omdat de stoffen giftig zijn. Maar nog altijd zijn PCS’s en hun afbraakstoffen (OH-PCB’s) terug te vinden in onze voedselketen, en aantoonbaar in ons bloed. Met name voor de ontwikkeling van baby’s is dit schadelijk, zo laat onderzoek van UMCG-promovendus Shalini Soechitram zien. De promovenda heeft de hoeveelheid PCB’s en OH-PCB’s gemeten en de effecten van deze stoffen onderzocht bij pasgeborenen tot de leeftijd van 18 maanden. Ze stelt vast dat de hoeveelheid PCB’s in het bloed van pasgeborenen de afgelopen jaren is gedaald, maar dat deze concentraties nog steeds schadelijk kunnen zijn. Soechitram laat zien dat PCB’s de werking van de schildklier van Nederlandse baby’s nog altijd beïnvloeden. Dit heeft mogelijk zijn weerslag op cognitieve en neurologische ontwikkeling. Ook stelt ze vast dat PCBs en OH-PCBs van invloed zijn op de motorische optimaliteit van pasgeborenen. Op het testikelvolume bij 3 en 18 maanden lijken de stoffen geen invloed te hebben. Het blijft dan ook van het grootste belang voor onze gezondheid om de toepassing van PCB’s en andere chemische stoffen te bestrijden, aldus Soechitram.

Prenatal exposure to organohalogen compounds and children's mental and motor development at 18 and 30 months of age

BACKGROUND: Organohalogen compounds (OHCs), i.e. polychlorinated biphenyls (PCBs, are wide-spread environmental pollutants known to be neurotoxic for the developing brain. The hydroxylated metabolites of PCBs, OH-PCBs, might be even more toxic due to their structure and interference with thyroid hormone metabolism. We found that prenatal exposure to OH-PCBs was associated with thyroid hormone metabolism at toddler age. Little, however, is known about the neurotoxicity of OH-PCBs in humans. OBJECTIVES: To determine whether prenatal background exposure to OHCs has an effect on mental and motor development in children at the age of 18 and 30 months. METHODS: One hundred and eighty-one healthy mother-infant pairs were included in this observational study performed in the Netherlands. We measured maternal pregnancy levels of PCB-153 and three OH-PCBs. In one part of the cohort we measured another nine PCBs and three OH-PCBs and in the other part we measured five brominated diphenyl ethers (BDEs), dichloro-diphenyldichloroethylene (p,p'-DDE), pentachlorophenol (PCP), and hexabromocyclododecane (HBCDD). We used the mental development index (MDI) and the motor development index (PDI) of the Bayley Scales of Infant Development II (BSID-II) to assess children's mental and motor development (mean = 100; delayed score <85). RESULTS: Higher prenatal PCB-153 levels were associated with a delayed MDI score at 18 months. None of the other compounds were associated with a delayed score, but several associations were found between OHC levels and BSID-II scores. The sum of all six OH-PCBs and three individual OH-PCBs, 4-OH-PCB-107, 3-OH-PCB-153, and 4'-OH-PCB-172, correlated positively with MDI at 30 months. The compound 3'-OH-PCB-138 showed a similar trend. A higher 4-OH-PCB-187 was associated with a lower MDI at 18 months. We found a similar trend for higher BDE-99. Higher BDE levels were associated with higher PDI at 18 months. The levels of p,p'-DDE-, PCP, and HBCDD were not associated with BSID-II scores at 18 months. CONCLUSIONS: Higher prenatal levels of PCB-153 were associated with a delayed MDI score at 18 months. None of the other compounds were associated with a delayed score, but several associations were found between OHC levels and BSID-II scores. Prenatal OH-PCBs were positively associated with mental development at 30 months, whereas one OH-PCB was negatively associated at 18 months. BDE levels were positively associated with psychomotor development. Prenatal p,p'-DDE, PCP, and HBCDD levels were not associated with neurodevelopment at 18 months