Department of Civil Engineering, SRM Institute of Science and Technology, Kancheepuram district, Tamil Nadu 603203, India; SRM Research Institute, SRM Institute of Science and Technology, Kancheepuram district, Tamil Nadu 603203, India.
Retired from Agricultural Research Service, Edward T. Schafer Agricultural Research Center, Biosciences Research Laboratory, 1616 Albrecht Blvd., Fargo, ND, 58102, United States.
Water Res. 2021 Feb 15;190:116668. doi: 10.1016/j.watres.2020.116668. Epub 2020 Nov 23.
The transboundary River Ganga serves as a conduit for meltwater from the Himalayas and is a major freshwater source for two thirds of Indian population before emptying into the Sundarban Delta, the largest estuary in the Bay of Bengal. Endocrine disrupting compounds (EDCs) such as phthalic acid esters (PAEs) and bisphenol A (BPA) used as organic plastic additives can pollute the aquatic environment receiving plastic litter. Hence, we have investigated these EDCs in water samples from Ganga and Sundarban wetland of India. Since these compounds exhibit estrogenic potential, we have further measured steroids and evaluated the estrogenic activity (estradiol equivalents, BioE2Eqs) using an in-vitro bioassay (E-Screen). Further BioE2Eqs were compared with the sum of predicted estradiol equivalents based on the chemical concentrations of PAEs and BPA by E-Screen (ChemE2Eq) and YES factors (ChemYES). Caffeine was measured as a marker for anthropogenic wastewater discharge. Results showed that the highest BioE2Eq (below the lowest observable effect of E2 on fish) was associated with sites having sewer outfalls in the middle stretch of the river, and concomitantly coinciding with the elevated concentrations of caffeine. Neither ChemE2Eq nor ChemYES correlated with measured BioE2Eqs. River concentrations of BPA (0.04-4.46 µg/L) and ∑plasticizers (0.43-7.63 µg/L) were higher than BPA (0.21-2.82 µg/L) and ∑plasticizers (0.85-2 µg/L) in the Sundarban wetland. The only steroids detected were androgens, found at four sites in Ganga (0.007 µg/L± 0.003, mean ± S.D.). The highest estimated ecotoxicological risk to aquatic insect and fish stemmed from BPA. A secondary effect, and a potential impact on human health could be reflected via fish consumption from the productive fisheries region along the lower stretch of River Ganga. Identification of areas of elevated estrogenicity, plasticizer and steroid concentrations in River Ganga can be used to design and implement interventions for the remediation of such emerging contaminants.
跨界河流恒河是来自喜马拉雅山的融水的通道，也是印度三分之二人口的主要淡水来源，然后流入孟加拉湾最大的河口——孙德尔本斯三角洲。作为有机塑料添加剂使用的邻苯二甲酸酯（PAEs）和双酚 A（BPA）等内分泌干扰化合物（EDCs）会污染接收塑料垃圾的水生环境。因此，我们调查了印度恒河和孙德尔本斯湿地的水样中的这些 EDCs。由于这些化合物具有雌激素潜力，我们进一步测量了类固醇，并使用体外生物测定法（E-Screen）评估了雌激素活性（雌二醇当量，BioE2Eqs）。进一步的 BioE2Eqs 与通过 E-Screen（ChemE2Eq）和 YES 因子（ChemYES）基于 PAEs 和 BPA 的化学浓度预测的雌二醇当量总和进行了比较。咖啡因被测量为人为废水排放的标志物。结果表明，最高的 BioE2Eq（低于鱼类雌二醇的最低可见效应）与河流中游有污水排放口的地点有关，同时与咖啡因浓度升高相吻合。ChemE2Eq 和 ChemYES 均与实测的 BioE2Eqs 无关。河水中的 BPA（0.04-4.46μg/L）和∑塑化剂（0.43-7.63μg/L）的浓度高于孙德尔本斯湿地中的 BPA（0.21-2.82μg/L）和∑塑化剂（0.85-2μg/L）。仅在恒河的四个地点检测到了雄激素等类固醇，浓度为 0.007μg/L±0.003（平均值±标准差）。BPA 对水生昆虫和鱼类的生态毒性风险最高。通过从恒河下游的生产性渔业区捕捞鱼类，可能会产生次要影响，并对人类健康产生潜在影响。识别恒河地区雌激素、塑化剂和类固醇浓度升高的区域，可以用于设计和实施干预措施，以修复这些新兴污染物。
