4种环境雌激素对淡水鱼卵黄蛋白原诱导的混合物效应研究

在个体水平上阐明环境雌激素类化合物对易受影响生物的联合毒性作用,探讨混合污染物联合作用和环境风险评价的研究方法.通过对鲫鱼血清卵黄蛋白原含量的相对变化和暴露浓度的非线性回归分析得出17α-乙炔基雌二醇(EE2)、17β-雌二醇(E2)、双酚A(BPA)、辛基苯酚(OP)及其等毒性混合物产生雌激素效应的剂量-反应关系,应用联合作用指数和相加作用模型研究4种环境雌激素的联合作用.各化合物非线性回归分析结果均以Weibull函数拟合效果最好,决定系数R2≥0.92;效应浓度值及其95%置信限通过自举抽样法得出,其中半效应浓度值EC50及其95%置信区间分别为0.0079(0.0068～0.0100)、0.0987(0.0900～0.1110)、63.50(56.58～70.62)和250.59(228.46～271.99)μg·L-1.4种环境雌激素混合物效应通过相加作用模型预测在全剂量范围内与实验结果相一致,呈现相似联合作用.相加作用模型是在各个浓度反应水平上展示化合物联合作用的性质,是切实可行的联合作用研究方法,而混合物效应通过联合作用指数评价存在许多不确定性.

Mixture Effects to Vitellogenin Induction by Four Environmental Estrogens in Freshwater Fish

Combined effects of estrogenic compounds to high risk life-form were demonstrated, and the study method on combined effects of environmental contaminant mixture and environmental risk assessment were also discussed. A nonlinear aggression was determined on the changes of plasma vitellogenin concentration in crucian carp via the environmental pollutant exposure concentration, and the concentration-response relationship was determined for the single chemical of estradiol, ethynylestradiol, bisphenol A, and octylphenol, and that of the mixed compounds at equipotent concentrations. The combined effects of the four xenoestrogens were tested using indices of mixture toxicity and the biomathematical models of concentration addition or independent action. Weibull function was indicated as the best-fit function (R2 > or = 0.92) with curve estimation, the 95% confidence limits of effect concentration was achieved using the bootstrap method, the media effective concentration (EC50) with 95% confidence interval was 0.007 9 (0.006 8-0.010 0), 0.098 7 (0.090 0-0.111 0), 63.50 (56.58-70.62) and 250.59 (228.46-271.99) Mg x L(-1) respectively. Results suggested that estrogenic chemicals acted together in an additive manner and the combined effects can be accurately predicted in whole range of exposure concentration by the concept of similar joint action or concentration addition.It is proved as a scientific and feasible method to apply the model of joint action whereas the outcome of indices with a great deal of indetermination.