五溴联苯醚(Penta-BDE)与重金属对水生无脊椎动物大型蚤Daphnia magna存活及其繁殖的联合毒性影响

主要研究了五溴联苯醚(Penta-BDE)与重金属镉(Cd)、铜(Cu)对水生甲壳类动物大型蚤Daphniamagna的48 h存活以及21 d繁殖的联合毒性影响。在15个混合处理组中,将3种化合物分别根据其半数致死质量浓度(将LC50作为一个毒性单位,One-TU)的0%,25%,50%,75%加以混合。与1-TU的结果相比较,结果分别分为质量浓度相加作用,大于质量浓度相加作用和小于质量浓度相加作用。根据大型蚤的存活率,质量浓度相加作用效应主要发生在75%w(Cd)+25%w(Pe-BDE),50%w(Cu)+50%w(Pe-BDE)以及75%w(Cu)+25%w(Pe-BDE)处理组中。大于质量浓度相加作用效应仅仅出现在25%w(Cd)+75%w(Cu)处理组中。基于大型蚤繁殖能力,质量浓度相加作用主要发生在75%w(Cd)+25%w(Pe-BDE),以及75%w(Cu)+25%w(Pe-BDE)处理组中。剩下的处理组均为小于质量浓度相加作用。出现该结果,也许是由五溴联苯醚与重金属的不同毒性机制造成。同时,实验结果也表明在联合毒性中,Cu和Cd的毒性作用大于Pe-BDE。

Joint Effect of Penta-BDE and Heavy Metals on Aquatic Invertebrate Daphnia magna Survival and Its Reproduction

The joint toxicity of Penta BDE (Pe BDE) and heavy metals including cadmium(Cd) and copper (Cu) on Daphnia magna was evaluated on the basis of determining the 48h survival and 21 day reproduction. Fifteen mixture treatments in which the chemicals were at 0, 25, 50, 75, and 100% of their individual median inhibition concentrations and made up to one toxic unit (TU) were applied. The response was classified as additive, greater than additive, or less than additive by comparing the measured TU with one. Based on the survival of Daphnia magna, additive responses occurred in the 75% Cd plus 25% Pe BDE, 50% Cu plus 50% Pe BDE and the 75% Cu plus 25% Pe BDE treatments. Greater than additive responses were only found in the 25% Cd plus 75% Cu treatment. For reproduction, additive responses occurred in the 75% Cd plus 25% Pe BDE，and 75% Cu plus 25% Pe BDE treatments. Less than additive interactions were found in other remaining mixtures. Cu and Cd played a greater role in toxicity than Pe BDE did. This may be attributed to the different toxicity mechanism between Pe BDE and metals.