Sah Ruchika, Talukdar Gautam, Khanduri Megha, Chaudhary Pooja, Badola Ruchi, Hussain Syed Ainul
Wildlife Institute of India, Chandrabani, Dehradun, 248001, India.
Heliyon. 2024 Jul 23;10(15):e35130. doi: 10.1016/j.heliyon.2024.e35130. eCollection 2024 Aug 15.
Dietary exposure risks of 39 multi-class Endocrine Disrupting Chemicals (EDCs) to the threatened Gangetic dolphins () were investigated in a conservation-priority segment of the Ganga River. Elevated EDCs bioaccumulation was observed across prey fish species, with di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) significantly contributing to the EDC burden. The concentrations of persistent organochlorines in prey revealed a shift from dioxin-like polychlorinated biphenyls (PCBs) to non-dioxin-like PCBs. The prevalence of regulated p,p' DDT (Dichlorodiphenyltrichloroethane) and γ-HCH (Lindane) residues suggests regional non-compliance with regulatory standards. The concentration of some EDCs is dependent on the habitat, foraging behavior, trophic level and fish growth. The potential drivers of EDCs contamination in catchment includes agriculture, vehicular emissions, poor solid waste management, textile industry, and high tourist influx. Risk quotients (RQs) based on toxicity reference value were generally below 1, while the RQ derived from the reference dose highlighted a high risk to Gangetic dolphins from DEHP, DDT, DnBP, arsenic, PCBs, mercury, and cadmium, emphasizing the need for their prioritization within monitoring programs. The study also proposes a monitoring framework to provide guidance on monitoring and assessment of chemical contamination in Gangetic dolphin and habitats.
在恒河的一个具有保护优先级的河段，对39种多类别内分泌干扰化学物质（EDCs）对濒危恒河豚（）的膳食暴露风险进行了调查。在被捕食的鱼类物种中均观察到了EDCs的生物累积量升高，其中邻苯二甲酸二（2-乙基己基）酯（DEHP）和邻苯二甲酸二正丁酯（DnBP）对EDC负担有显著贡献。被捕食物种中持久性有机氯的浓度显示出从二噁英类多氯联苯（PCBs）向非二噁英类PCBs的转变。受管制的p,p'滴滴涕（二氯二苯三氯乙烷）和γ-六氯环己烷（林丹）残留的普遍存在表明该地区未遵守监管标准。一些EDCs的浓度取决于栖息地、觅食行为、营养级和鱼类生长。流域内EDCs污染的潜在驱动因素包括农业、车辆排放、固体废弃物管理不善、纺织业和大量游客涌入。基于毒性参考值的风险商数（RQs）通常低于1，而从参考剂量得出的RQ突出显示DEHP、滴滴涕、DnBP、砷、PCBs、汞和镉对恒河豚构成高风险，强调需要在监测计划中对它们进行优先排序。该研究还提出了一个监测框架，为恒河豚及其栖息地化学污染的监测和评估提供指导。
