Transplacental transfer of phenyltins from a pregnant Dall’s porpoise (Phocoenoides dalli) to her fetus

The maternal to fetal transfer of monophenyltin (MPT), diphenyltin (DPT), and triphenyltin (TPT) was investigated for the first time in a cetacean species, a mother–fetus pair of Dall’s porpoises (Phocoenoides dalli) collected off the Sanriku coast, Japan. The mother individual was contaminated by phenyltin compounds, and the muscle, blubber, and liver accounted for 90% of the total phenyltin burden. A two-generation phenyltin contamination via transplacental transfer was demonstrated. This study revealed that the transfer rate was 0.29% for total phenyltins to a fetus of about 6-month-old. Unlike in the mother, the fetal liver could not be considered the target organ for all the phenyltins studied. In a ca. 100 kg-weight mother Dall’s porpoise and its fetus of 2.21 kg-weight, approximately 153 μg (TPT, 139 μg; DPT, 9.4 μg; MPT, 4.2 μg) and 0.44 μg of total phenyltins (TPT, 0.38 μg; DPT, 0.03 μg; MPT, 0.03 μg) were found, respectively. The body burden of TPT consisted of 91% and 86% of the total phenyltin burdens in the maternal and fetal bodies, respectively.