Water Research 2009-01-01

Comparison between the short-term and the long-term toxicity of six triazine herbicides on photobacteria Q67

Xiang-Wei Zhu, Shu-Shen Liu, Hui-Lin Ge, Yan Liu, Xiang-Wei Zhu, Shu-Shen Liu, Hui-Lin Ge, Yan Liu

Index: Water Res. 43(6) , 1731-9, (2009)

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Abstract

The bioluminescence inhibition of six triazine herbicides including desmetryne (DES), simetryn (SIM), velpar (VEL), prometon (PRO), metribuzin (MET), and aminotriazine (AMI) on Vibrio qinghaiensis sp.-Q67 (Q67) was determined to investigate the effects of exposure duration on the ecotoxicological relevance of triazine herbicides. Based on the short-term microplate toxicity analysis (MTA), a long-term MTA was established to assess the impact of exposure time on the toxicities of the herbicides. The results show that the long-term toxicities of DES and SIM are similar to their short-term toxicities, and the long-term toxicities of VEL, PRO, and MET are higher than their short-term toxicities, while AMI without short-term toxicity has a high long-term toxicity. In addition, a parabolic relationship was found between the pEC 50 (the negative logarithm of the EC 50, log 1/EC 50) and the logarithm of octanol–water partition coefficient (log K ow). To better understand their toxicity process, the time-dependent toxicities of the six herbicides on Q67 were determined over a period of 12 h during which measurements were taken every 30 min to generate an integral effect surface related to both concentration and duration.