重庆长江流域水体中8种典型环境雌激素污染特征

Estrogens in Surface Water of the Yangtze River in Chongqing Section

选择重庆市长江流域为研究区域,调查平水期和蓄水期水体中8种典型环境雌激素雌酮(E1)、雌二醇(E2)、雌三醇(E3)、己烯雌酚(DES)、炔雌醇(EE2)、4-壬基酚(4-NP)、4-辛基酚(4-t-OP)和双酚A(BPA)的浓度、组成和分布特征,并对其雌激素活性进行风险评价。结果表明,重庆市长江流域水体中除E2外,其余7种环境雌激素均有检出,总浓度范围为46.16~10985.79 ng·L^-1,主要污染物为4-NP和BPA。平水期4-t-OP、BPA浓度显著高于蓄水期,而4-NP则相反。空间分布上,各采样位点的环境雌激素污染状况相差较大,并未表现出明显的流向变化趋势或干支流差异。风险评估结果表明,平水期52%的位点及蓄水期22%的位点雌激素总活性高于1 ng·L^-1,提示具有高雌激素活性风险,其中,E1为平水期主要雌激素活性贡献物质,而4-NP为蓄水期主要雌激素活性贡献物质。

Concentrations,compositions,and distribution of eight estrogens(EEs),including estrone(E1),17β-estradiol(E2),estriol(E3),diethylstilbestrol(DES),17α-ethinylestradiol(EE2),4-nonylphenol(4-NP),4-tert-octylphenol(4-t-OP),and bisphenol A(BPA),were investigated in surface water of the Yangtze River in Chongqing Section,and the risk of estrogenic activity was also evaluated.The results showed that all EEs were detected in the water except for E2,with total concentrations ranging from 46.16 to 10985.79 ng·L-1,and the EEs dominated by 4-NP and BPA.The concentrations of 4-t-OP and BPA in dry season were significantly higher than those in wet season,while an opposite trend were observed for the concentrations of 4-NP.Spatial distributions showed that concentrations of EEs in water of the sampling sites varied greatly;however,there were no clear trend along the river or significant difference between the main stream and tributaries.Risk assessment for estrogenic activity showed that the total estradiol equivalency(EEQ)values were greater than one at 52%of the sampling sites in the dry season and at 22%of the sampling sites in wet season,indicating a high risk of the EEs.E1 and 4-NP were the main contributors of estrogenic activity in dry and wet seasons,respectively.