氯酚类化合物对淡水发光菌Q67的联合毒性

Joint Toxicity of Chlorophenols to Freshwater Photobacterium Vibrio Qinghaiensis sp.-Q67

以淡水发光菌Q67——青海弧菌Q67(Vibrio qinghaiensissp.-Q67)为生物材料,分别研究了2-氯酚,2,4-二氯酚和2,3,4-三氯酚及其等剂量、等毒性单位配比混合物的发光抑制毒性,并采用相加指数法和相似性参数法评价了混合物的联合毒性效应.结果表明:3种氯酚对Q67菌的EC50值分别为99.57,25.19和3.42 mg/L,说明氯酚类化合物对发光菌的急性毒性随着氯原子数目的增加而增大,氯酚的二元和三元混合物的毒性作用明显高于化合物的单一毒性.2种评价指数均采用评价标准的95%置信区间,避免了由实验误差引起的不准确性.氯酚混合物对Q67菌的联合毒性效应主要表现为简单的相加作用,只有2-氯酚与2,3,4-三氯酚的组合为弱的协同作用.氯酚的等剂量和等毒性配比混合物毒性作用的评价结果相一致.

Using freshwater photobacterium Q67（ Vibrio qinghaiensis sp .-Q67） as indication organism, the single acute toxicity induced by 2- chlorophenoi, 2,4-dichlorophenol, 2,3,4-trichlorophenol, and the joint toxicity of binary and trinary mixtures in equiconcentration and equitoxicity ratios were determined, respectively. Additive Index and Similarity Parameter were used to evaluate the joint effects. The results showed that EC50 values of 3 individual chlorophenols to Q67 were 99.57, 25.19 and 3.42 mg/L respectively, which revealed that the acute toxicity of chlorophenols increased with the number of chlorine on the benzene ring. The mixture effects were significantly higher than the single toxicity of 3 individuals. The 95 % confidence intervals were used for 2 assessment indexes to reduce the inaccuracies due to experimental errors. Their evaluation results were almost identical. The joint action of cblorophenol mixtures were identified as being simple additive, except that 2-chlorophenol and 2,3,4-trichlorophenol group showed weak synergistic effect. The same assessment results were concluded in both equiconcentration and equitoxicity mixtures.