汞和农药氯氰菊酯对蛋白核小球藻的复合污染急性毒性

Combined Toxicity of Mercury and Cypermethrin to Chlorella pyrenoidosa

采用实验室培养方法,研究不同浓度的Hg^(2+)和不同浓度的农药氯氰菊酯单独及联合作用对蛋白核小球藻(Chlorella pyrenoidosa)的急性毒性效应。结果表明,Hg^(2+)和氯氰菊酯单独作用时,较低浓度的Hg^(2+)(小于5μg/L)和氯氰菊酯(小于2 mg/L)对小球藻无明显抑制作用,但随着浓度增大,抑制作用增强。且半效应浓度(EC50)值均随时间的延长而减小;二者联合作用时,随着时间延长,EC50与污染物质单独作用时的趋势相同,EC50-24 h为2.366 mg/L,EC50-96 h为1.711 mg/L,存在明显的时间-效应关系。并且根据水生毒理联合效应相加指数法得出,低浓度和高浓度组均表现拮抗作用,Hg^(2+)与氯氰菊酯的同时存在降低了两者对蛋白核小球藻的生长抑制作用。

Using the laboratorial culture method, the separate and combined effects of different concentrations of Hg2＋ and various concentrations of the pesticide of cypermethrin in the acute toxic effects on Chlorella pyrenoidosa were studied. The results showed that, when Hg2＋ combines alone with cypermethrin, the lower concentrations of Hg2＋ （less than 5μg/L） and cypermethrin （less than 2mg/L） had no significant inhibitory effect on chlorella, but as the concentration increases, the inhibition increased. And ECso values were decreased along with time lasting. Their combined effect, with time lasting, half effect concentration （ECso） and that of pollutants alone shares the same trend, EC50-24h was 2. 366 mg/L, ECs0-96h was 1. 711 mg/L, there is obviously time-effect relationship. According to the combined effects of aquatic toxicology and additive index method, the low concentration group and high concentration group both showed antagonistic effect, Hg2＋ and cypermethrin coexists, both of which reduce the growth of inhibition of Chlorella pyrenoidosa.