Transfer of mercury and phenol derivatives across the placenta of Baltic grey seals (Halichoerus grypus grypus)

• Published in: Environmental pollution (1987) Vol. 231; no. Pt 1; pp. 1005 - 1012
• Main Authors: Nehring, Iga, Grajewska, Agnieszka, Falkowska, Lucyna, Staniszewska, Marta, Pawliczka, Iwona, Saniewska, Dominika
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2017
• Subjects: Animals; Baltic States; Benzhydryl Compounds; Endocrine Disruptors; Environmental Monitoring; Female; Grey seal; Maternal transfer; Mercury - metabolism; Organic mercury; Phenol - metabolism; Phenol derivatives; Phenols; Placenta; Placenta - metabolism; Pregnancy; Seals, Earless - metabolism; Selenium; Water Pollutants, Chemical - metabolism; Organic mercury; Phenol derivatives; Placenta; Selenium; Maternal transfer; Grey seal
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2017.08.094

The placenta is an intermediary organ between the female and the developing foetus. Some chemical substances, including the most harmful ones, exhibit the ability to accumulate in or penetrate through the placenta. The aim of the study was to determine the role of the placenta of the Baltic grey seal (Halichoerus grypus grypus) in the transfer of endocrine disrupting compounds (EDCs) - (bisphenol A, 4-tert- octylphenol, 4- nonylphenol), as well as total and organic mercury. 30 placentas were collected from grey seals pupping under human care at the Hel Marine Station in the years 2007–2016. The assays were conducted using the technique of high-preformance liquid chromatography (phenol derivatives) and atomic absorption spectrometry (mercury and selenium). A measurable level of EDCs was indicated in the placentas of grey seals. It was established that the inorganic Hg form was accumulated in the placenta, and that its concentrations were an order of magnitude higher than the concentrations of the organic form, which penetrated to the foetus. Similar observations were made for phenol derivatives - bisphenol A, 4-tert- octylphenol and 4-nonylphenol. For this compound group the placenta was a barrier, but the properties of phenol derivatives suggest the possibility of their penetration through this organ. [Display omitted] •The grey seal's placenta may limit the transfer of BPA, OP, NP and HgIN to the foetus.•The placenta does not constitute a barrier for HgORG.•Demethylation may occur in the placenta.•Se:Hg molar ratios indicate excess Se in relation to Hg in the placentas.•Proteins and fats do not affect the accumulation of mercury and phenol derivatives in the placenta. On the basis of the obtained results it was determined that the placenta may limit the transfer of inorganic mercury and phenol derivatives and is probably transparent for organic mercury.