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

A retrospective study of PBDEs and PCBs in human milk from the Faroe Islands

BACKGROUND: Persistent organic pollutants (POPs) in wildlife and humans remain a cause of global concern, both in regard to traditional POPs, such as the polychlorinated biphenyls (PCBs), and emerging POPs, such as the polybrominated diphenyl ethers (PBDEs). To determine the time related concentrations, we analyzed human milk for these substances at three time points between 1987 and 1999. Polychlorobiphenylols (OH-PCBs), the dominating class of PCB metabolites, some of which are known to be strongly retained in human blood, were also included in the assessment. METHODS: We obtained milk from the Faroe Islands, where the population is exposed to POPs from their traditional diet (which may include pilot whale blubber). In addition to three pools, nine individual samples from the last time point were also analyzed. After cleanup, partitioning of neutral and acidic compounds, and separation of chemical classes, the analyses were carried out by gas chromatography and/or gas chromatography/mass spectrometry. RESULTS: Compared to other European populations, the human milk had high PCB concentrations, with pool concentrations of 2300 ng/g fat 1987, 1600 ng/g fat in 1994, and 1800 ng/g fat in 1999 (based on the sum of eleven major PCB congeners). The nine individual samples showed great variation in PCB concentrations. The OH-PCBs were present in trace amounts only, at levels of approximately 1% of the PCB concentrations. The PBDE concentrations showed a clear increase over time, and their concentrations in human milk from 1999 are among the highest reported so far from Europe, with results of individual samples ranging from 4.7 to 13 ng/g fat CONCLUSION: Although remote from pollution sources, the Faroe Islands show high concentrations of POPs in human milk, particularly PCBs, but also PBDEs. The PBDEs show increasing concentrations over time. The OH-PCB metabolites are poorly transferred to human milk, which likely is related to their acidic character

Environmental influences on reproductive health: the importance of chemical exposures

Chemical exposures during pregnancy can have a profound and life-long impact on human health. Due to the omnipresence of chemicals in our daily life, there is continuous contact with chemicals in food, water, air and consumer products. Consequently, human biomonitoring studies show that pregnant women around the globe are exposed to a variety of chemicals. In this review, we provide a summary of current data on maternal and fetal exposure as well as health consequences from these exposures. We review several chemical classes including polychlorinated biphenyls (PCBs), perfluoroalkyl substances (PFAS), polybrominated diphenyl ethers (PBDEs), phenols, phthalates, pesticides, and metals. Additionally, we discuss environmental disparities and vulnerable populations, and future research directions. We conclude by providing some recommendations for prevention of chemical exposure and its adverse reproductive health consequences

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.

Comparison of dioxin and PCB concentrations in human breast milk samples from Hong Kong and the Netherlands

The adverse effects of dioxins and polychlorinated biphenyls (PCBs) on human health are of increasing concern. These lipophilic compounds are concentrated through the food chain and are present in human milk. This study compares PCB levels in human milk samples from Hong Kong and Dutch mothers. Ten breast milk samples from Hong Kong and 10 from the Netherlands were collected during home visits between 2 and 6 weeks postpartum. Total toxic equivalence (TEQ) of dioxin and PCBs were determined using the DR-CALUX® bioassay. The total dioxin and PCB levels in breast milk samples for Hong Kong ranged from 3.1 to 29.9 pg TEQ

Polychlorinated biphenyl exposure and deiodinase activity in young infants

Background: Several studies have shown effects of polychlorinated biphenyls (PCBs) on serum thyroid hormone levels in pregnant woman and their infants, while other studies did not find such effects. How PCBs might affect thyroid hormone metabolism, is still unclear. Potential mechanisms are direct influence on the thyroid gland, binding to thyroid binding proteins, increased excretion or metabolism of thyroid hormones by deiodinases or sulfatases. It is also not well known whether the effect on thyroid hormone levels is caused by PCBs themselves, or by their hydroxylated metabolites (OH-PCBs). Objective: To determine the effects of perinatal exposure to PCBs and OH-PCBs on thyroid hormone levels in cord blood and in serum of newborn infants. Methods: In a Dutch cohort of 100 mother-infant pairs, exposed to background PCB levels, correlations were assessed between 10 PCBs and 6 OH-PCBs in maternal blood during pregnancy and serum thyroxine (T4), T4 sulfate (T4S), triiodothyronine (T3), reverse T3 (rT3), thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) levels in cord blood and in serum of three- and 18-month-old infants. We corrected for age of the mother, gestational age, gender and type of feeding. Results: After correction, prenatal levels of three of 10 measured PCBs showed a positive correlation with cord serum T3, and four PCBs showed a negative correlation with cord serum rT3. After correction, two PCBs and the sum of the 10 measured PCBs were positively correlated with the cord serum T3/rT3 ratio, an indicator of deiodinase 3 activity. No correlations were found between PCBs and T4, TSH and TBG in cord blood. 4-OH PCB-107 was correlated with T4 at 3 months and T4, T4S and T3 at 18 months. Conclusion: Our results suggest that PCBs have a negative effect on deiodinase type 3 activity, as reflected by a positive correlation with the T3/rT3 ratio. We identified a potential mechanism by which PCBs may affect thyroid hormone metabolism during human development. 2016 Elsevier B.V. All rights reserved

Prenatal Exposure to Polychlorinated Biphenyls and Their Hydroxylated Metabolites is Associated with Neurological Functioning in 3-Month-Old Infants

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 = 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