论文部分内容阅读
Objective: To investigate the use of a biomarker for assessment of the effects on the tropical chironomid, Chironomus javanus (C. javanus), Kiffer of sediment contaminated with an insecticide (chlorpyrifos). Methods: A wide range of biological responses to the tropical chironomid exposed were measured, including survival, growth rate and Acetylcholinesterase (AChE) activity. Results: The measured median lethal concentration (96 h LC50) of chlorpyrifos to C. javanus was 0.056 (95％ CI 0.024–0.124) μg/kg. For sub-chronic levels of chlor-pyrifos between 0.001 and 0.25μg/kg administered for 10 days, the effects on the growth of C. javanus were reduced (larva size, head structure width and dry weight) at the significance level (P < 0.01) and the effects were concentration dependent. Following exposure to chlorpyrifos at the level of 0.001μg/kg for 48 and 96 h, the AChE activity in C. javanus was inhibited compared with control samples (P<0.05). Conclusions: This study demonstrated that C. javanus was sensitive when exposed to chlorpyrifos. This species could serve as a potential biomarker for assessing pesticide contamination at low environmental persistence and provides limited effects data on the sensitivity of tropical biota to contaminants for ecological risk assessment of organo-phosphate pesticides in the tropical aquatic ecosystem.