Organotins Remain a Serious Threat to the Indo-Pacific Humpback Dolphins in the Pearl River Estuary

Abstract

Marine mammals often accumulate high levels of environmental contaminants, even those that are globally regulated regarding usage, raising concerns about their health status. Here, we conducted the first investigation of tissue distribution, spatiotemporal trends, and potential risks of six organotin compounds (OTs) in Indo-Pacific humpback dolphins (n = 101) from the northern South China Sea during 2003–2021. We detected the highest level of hepatic triphenyltin in these humpback dolphins compared with the results reported in cetaceans globally, and the liver accumulated the highest OT concentrations than other analyzed tissues. Despite the downward trend of butyltins in humpback dolphins after the global ban on the use of OTs as antifouling paints, levels of phenyltins have continued to increase over the past 20 years, suggesting that the other applications of phenyltins in South China remain prevalent. In vitro and in vivo analyses revealed that tissue-relevant doses of OTs could induce agonistic effects on the dolphin peroxisome proliferator-activated receptor γ as a master regulator of lipid homeostasis and altered the dolphin fatty acid profiles. Our results highlight the lipid-disrupting effects of current OT exposure in humpback dolphins and emphasize the need for further efforts to eliminate OT contamination in South China.

Estimation of Per- and Polyfluorinated Alkyl Substance Induction Equivalency Factors for Humpback Dolphins by Transactivation Potencies of Peroxisome Proliferator-Activated Receptors

“…, Baikal seal and human beings) have revealed that co-exposure of PFAS with other hazardous contaminants ( e.g. , TBT, PBDE 47, TBBPA, and TCBPA) exhibits additional effects on PPAR at concentrations relevant for humpback dolphins. ,, Actually, the populations of PRE humpback dolphin accumulated mixtures of PFAS congeners and other environmental PPAR ligands, such as alternative halogenated flame retardants, organotins, and PCBs. ,, Thus, the potential health risks of high-level PFOS and other PFAS congeners in PRE dolphins are of concern.…”

“…pBIND-dolphin/human-PPARs all contain a yeast Gal4 DNA-binding domain, which can activate the GAL4-UAS-dependent LRG. The detailed procedures for LRG assay were carried out as previously described with some modifications. − Briefly, HEK 293T cells were plated at a density of 4 × 10 4 cells per well in 96-well plates in phenol-red free Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum. After cells attached to the wells overnight, the medium was replaced with opti-MEM I reduced serum medium (Invitrogen), and the cells were cotransfected with the fusion expression vector pBIND-dolphin/human-PPARs and the luciferase reporter vector pGL4.35­[luc2P/9XGAL4UAS/Hygro] at a mass ratio of 1:2 using the ViaFect Transfection Reagent (Promega).…”

“…42,48,49 Actually, the populations of PRE humpback dolphin accumulated mixtures of PFAS congeners and other environmental PPAR ligands, such as alternative halogenated flame retardants, organotins, and PCBs. 14,38,50 Thus, the potential health risks of high-level PFOS and other PFAS congeners in PRE dolphins are of concern.…”

Transgenerational Effects and Mechanisms of Tributyltin Exposure on Neurodevelopment in the Male Offspring of Rats

“…Tributyltin, a component of marine antifouling paint, can be enriched in the human body through the food chain, posing a threat to human health. , Tributyltin pollution is an important problem in some coastal areas. − Butyltin in seafood from the Polish Baltic Sea coast is as high as 1132 ng Sn/g dw . In humans, median levels of total tin and organotin compounds detected in urine samples of pregnant women and adults in Iowa, USA, were 0.20 ng/mL and 0.57 ng/mL, respectively .…”