A research group led by Associate Professor Katsura Nomiyama of the Center for Coastal Environmental Sciences, Ehime University, has conducted polychlorinated biphenyls and theirs that adversely affect cranial nerve development from the brains of fetal animals in the early, middle and late stages of pregnancy in wild Japanese monkeys. The metabolite was detected for the first time in the world.
In recent years, the effect of hydroxide PCB (OH-PCB), which is a metabolite of polychlorinated biphenyl (PCB) (Note), on neurodevelopment has been suspected. It has been pointed out.Elucidation of the internal behavior of OH-PCB in the fetal and early childhood and risk assessment are required, but there are few cases of analysis of OH-PCB related to the fetal.There have been reports of human umbilical cord blood in primates, but no reports of OH-PCB studies in fetal tissue.
This time, we analyzed PCB and OH-PCB in wild Japanese macaques in the brain, liver, and placenta of the fetus in the early, middle, and late stages of pregnancy.As a result, OH-PCB was detected in all brain, liver and placenta samples.It was shown that the placenta-mediated transfer between mother and child in Japanese macaques, as well as the transfer and retention in the brain from the very early stage of development (embryo stage).In particular, the amount of pollutants transferred was significantly increased during the early fetal development stage (embryonic stage to middle fetal stage).The concentration level in the brain is higher than the concentration that suppresses the development of brain nerve cells reported in previous studies, and there is concern about the influence of OH-PCB transferred to the brain on nerve development.
These results raise concerns about the potential risk of OH-PCB to sensitive and well-developed early-stage embryos. Similar to human fetuses, whose PCB contamination levels are presumed to be higher than in Japanese macaques. It is considered that the possibility of migration and accumulation of PCBs is extremely high, and it is required to evaluate the effects on the cranial nerve system.
Note: Polychlorinated biphenyls have been widely used industrially, but are currently banned due to their harmfulness.There are concerns about the expansion of environmental risks due to processing delays and unauthorized disposal.
