| 1. |
- Björvang, Richelle D., et al.
(författare)
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Mixtures of persistent organic pollutants are found in vital organs of late gestation human fetuses
- 2021
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- Persistent organic pollutants (POPs) are industrial chemicals with long half-lives. Early life exposure to POPs has been associated with adverse effects. Fetal exposure is typically estimated based on concentrations in maternal serum or placenta and little is known on the actual fetal exposure. We measured the concentrations of nine organochlorine pesticides (OCPs), ten polychlorinated biphenyl (PCB) congeners, and polybrominated diphenyl ether (PBDE) congeners by gas chromatography – tandem mass spectrometry in maternal serum, placenta, and fetal tissues (adipose tissue, liver, heart, lung and brain) in 20 pregnancies that ended in stillbirth (gestational weeks 36–41). The data were combined with our earlier data on perfluoroalkyl substances (PFASs) in the same cohort (Mamsen et al. 2019). HCB, p,p’-DDE, PCB 138 and PCB 153 were quantified in all samples of maternal serum, placenta and fetal tissues. All 22 POPs were detected in all fetal adipose tissue samples, even in cases where they could not be detected in maternal serum or placenta. Tissue:serum ratios were significantly higher in later gestations, male fetuses, and pregnancies with normal placental function. OCPs showed the highest tissue:serum ratios and PFAS the lowest. The highest chemical burden was found in adipose tissue and lowest in the brain. Overall, all studied human fetuses were intrinsically exposed to mixtures of POPs. Tissue:serum ratios were significantly modified by gestational age, fetal sex and placental function. Importantly, more chemicals were detected in fetal tissues compared to maternal serum and placenta, implying that these proxy samples may provide a misleading picture of actual fetal exposures.
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| 2. |
- Björvang, Richelle D., et al.
(författare)
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Persistent organic pollutants and the size of ovarian reserve in reproductive-aged women
- 2021
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- Industrial chemicals such as persistent organic pollutants (POPs) have been associated with reduced fertility in women, including longer time-to-pregnancy (TTP), higher odds for infertility, and earlier reproductive senescence. Fertility is highly dependent on the ovarian reserve, which is composed of a prenatally determined stock of non-growing follicles. The quantity and quality of the follicles decline with age, thereby eventually leading to menopause. In the clinical setting, assessing ovarian reserve directly through the histological analysis of follicular density in ovaries is not practical. Therefore, surrogate markers of ovarian reserve, such as serum anti-Müllerian hormone (AMH) are typically used. Here, we studied associations between chemical exposure and ovarian reserve in a cohort of pregnant women undergoing elective caesarean section (n = 145) in Stockholm, Sweden. Full data (histological, clinical, serum) were available for 50 women. We estimated the size of the reserve both directly by determining the density of follicles in ovarian cortical tissue samples, and indirectly by measuring AMH in associated serum samples. Concentrations of 9 organochlorine pesticides (OCPs), 10 polychlorinated biphenyls (PCBs), 3 polybrominated diphenylethers (PBDEs) and 9 perfluoroalkyl substances (PFAS) were determined in serum, and clinical data were retrieved from electronic medical records. Healthy follicle densities (median 0, range 0–193 follicles/mm3) and AMH levels (median 2.33 ng/mL, range 0.1–14.8 ng/mL) varied substantially. AMH correlated with the density of growing follicles. Twenty-three chemicals detected in more than half of the samples were included in the analyses. None of the chemicals, alone or as a mixture, correlated with AMH, growing or atretic follicles. However, HCB, transnonachlor, PCBs 74 and 99 were associated with decreased non-growing follicle densities. HCB and transnonachlor were also negatively associated with healthy follicle density. Further, mixture of lipophilic POPs (PBDE 99, p,p’-DDE, and PCB 187) was associated with lower non-growing follicle densities. In addition, exposure to HCB, p,p’-DDE, and mixture of OCPs were significantly associated with higher odds of infertility. The results suggest that exposure to chemicals may reduce the size of ovarian reserve in humans, and strongly encourage to study mechanisms behind POP-associated infertility in women in more detail.
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