Maternal transfer and body distribution of legacy and emerging persistent organic pollutants (POPs) in finless porpoises (Neophocaena asiaeorientalis) collected from Korean coastal waters

Abstract

Marine mammals accumulate high levels of persistent organic pollutants (POPs) as top-predator in marine food web. Representative POPs, polychlorinated biphenyls (PCBs), organichlorine pesticide (OCPs), and polybrominated diphenyl ethers (PBDEs) are of global concern because of their long-range transportability, biomagnifications potential, and toxicity. Based on strong evidences on toxicity and environmental persistence of PBDEs, emerging flame retardants have been introduced as alternative or replacement. These are novel brominated flame retardants (NBFRs) and dechlorane plus (DP), which are of global concern due to the pseudo-POPs characteristics. To date, limited information is available on the occurrence and body distribution of legacy and emerging BFRs in marine mammals. Moreover, understanding on maternal transfer process of theses contaminants in scarce. In our study, we collected four mother-fetus paired samples of finless porpoises (Neophocasena asiaeorientalis) from western coastal water of Korea, to investigate the occurrence, body distribution, and maternal transfer of PCBs, OCPs, PBDEs, NBFRs, and DP in different organ tissues (Blubber, kidney, stomach, muscle, melon, liver, ovary, stomach content, heart, mammary gland, lung, intestine, pancreas, mesenteric lymphnods, uterus, cord, fetal sac and brain) of marine mammals. Average concentration of PCBs, OCPs, PBDEs, NBFRs, and DP in mother’s blubber tissues were 17.0, 407, 27.3, 2.73 and 0.10 ng/g wet weight, respectively. Average concentration of PCBs, OCPs, PBDEs, and NBFRs in fetus’s blubber tissues were 5.53, 136, 5.70, 0.73 ng/g wet weight respectively. DP was not detected in blubber tissues of fetus, implying a limited maternal transfer. In all organs, OCPs showed the highest concentration (wet weight based) followed by PCBs and PBDEs. The other tissues of the fetuses were underdeveloped, and POPs seemed to be transferred preferentially to the blubber as the final stored organ for POPs in the fetus.