【摘要】 通过研究不同盐度条件下11种有机磷农药对扁藻的相对增长率（K）和叶绿素a含量的影响，得到S＝30（接近近岸海水盐度值）和S＝20时（接近河口区海水盐度值）的半数有效浓度，并比较其大小。盐度作为环境因子，影响到有机磷农药的毒性。研究发现，有的有机磷农药在低浓度时出现一定限度的促生长作用；容易进攻细胞膜的有机磷农药对扁藻的致毒性相对较强；此外，有机磷农药的毒性大小与其结构密切相关，含有苯环结构的有机磷农药毒性大于不含有苯环结构的有机磷农药的毒性。结构、组成相似条件下，脂溶性大，分子类型复杂的有机磷农药毒效大。其中辛硫磷除含有苯环结构外，尚含有氰基，具有特别高的毒性。更多还原

【Abstract】 Study on the effects of 11 organic phosphorus pesticides on the relative growth rate(K) and Chl-a (ug/L) of Platymonas spp., The observation and comparation of the EC50 in S =30 (nearing to the salt content in the coast) and S = 20 (nearing to the salt content in the estuary) were done. As a environmental factor, the salt content effects on the toxicity of the organicphosphorus pesticides. We also have found out effect of some organic phosphorus pesticides in lowlevels; the more active to the cell membrane, the more poisonous pesticide is. Moreover, the toxicity greatly relate with the structures; with the similiar composition and structure, the more offwater ability and the more complicated structure, the more poisonous the organic phosphorus pesticide is; the toxicity with phenol structures are more poisonous than those without phenol structures; and the phoxin is the most poisonous one with-CN group besides phenol structure.更多还原