Acta Chimica Sinica ›› 2019, Vol. 77 ›› Issue (10): 1008-1016.DOI: 10.6023/A19060197 Previous Articles     Next Articles



郑乔峰, 居珍, 刘树深*()   

  1. 同济大学环境科学与工程学院 长江水环境教育部重点实验室 上海污染控制与生态安全研究院 上海 200092
  • 投稿日期:2019-06-03 发布日期:2019-08-13
  • 通讯作者: 刘树深
  • 基金资助:

Combined Toxicity of Dichlorvos and Its Metabolites to Vibrio qinghaiensis sp.-Q67 and Caenorhabditis elegans

Zheng, Qiao-Feng, Ju, Zhen, Liu, Shu-Shen*()   

  1. College of Environmental Science and Engineering, Tongji University, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092
  • Received:2019-06-03 Published:2019-08-13
  • Contact: Liu, Shu-Shen
  • Supported by:
    Project supported by the National Natural Science Foundation of China(21437004);Project supported by the National Natural Science Foundation of China(21677113);the Fundamental Research Funds for the Central Universities(22120180246)

Pesticides and their metabolites often coexist in the real environment. The combined toxicity (synergism or antagonism) between pesticide and metabolites directly affects the environment risk assessment of pesticide. Dichlorvos (A) has three main metabolites, 2,2-dichloroethanol (B), 2,2-dichloroacetic acid (C) and dimethyl phosphate (D), in water and soil environment. Under different environmental conditions, metabolites with various concentration compositions form a variety of mixtures with dichlorvos. In this paper, five mixture rays with different mixture ratios were selected by optimal experimental design method. A typical aquatic (Vibrio qinghaiensis sp. -Q67) and a soil organisms (Caenorhabditis elegans) were selected as the tested organisms. The photoluminescence inhibitory toxicity (IT) of parent A and its metabolites B, C and D as well as their mixtures to Q67 and the lethal toxicity (LT) to C. elegans at different exposure time and concentration levels were determined by microplate toxicity analysis. The combination index with 95% observation-based confidence intervals was used to evaluate the change of combined toxicity of each mixture ray under different exposure times and the concentration levels. The results showed that the ITs of parent A and two metabolites C and D to Q67 do not change with the exposure time, but the IT of metabolite B at 12 h is significantly larger than that at 0.25 h. However, at two exposure times, the IT of parent A is greater than that of any of metabolites. The LTs of A and B, C and D to C. elegans do not change with the exposure time. The LTs of A, C and D to C. elegans are basically the same and significantly greater than that of B. The ITs of five mixture rays to Q67 at 12 h are significantly greater than those at 0.25 h at various concentration levels. The combined toxicities of the mixture rays to Q67 are concentration additive at low concentration levels and antagonistic at high concentration levels whether at 0.25 h or 12 h. For C. elegans, the LTs of five mixture rays at various concentration levels do not basically change with the exposure time. At two exposure times (12 h and 24 h), the combined toxicities of mixture rays are concentration additive except for the slight antagonism in the rays of R2 and R5.

Key words: pesticide, multicomponent mixture, uniform design ray, basic concentration composition, time-dependent toxicity