Li Huizhen, You Jing
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China; University of Chinese Academy of Sciences, Beijing, China.
Environ Toxicol Chem. 2015 Mar;34(3):640-8. doi: 10.1002/etc.2851. Epub 2015 Feb 2.
A tiered ecological risk assessment was applied to quantitatively refine the overall probabilistic risk of cypermethrin, a pyrethroid insecticide, to aquatic organisms. These results were then validated through the bioassays using field water from an urban stream, Chebei Creek in Guangzhou, South China. Seventeen water samples were collected along Chebei Creek for evaluation. In total, 71% of the field waters were acutely toxic to Hyallela azteca and 24% of the waters caused 100% mortality. Toxic unit evaluation suggested that cypermethrin was one of the main contributors to toxicity. The tiered ecological risk assessment approach (deterministic quotient method and probabilistic methods, including joint probability curve and Monte Carlo Simulation) suggested that cypermethrin posed significant threats to aquatic ecology in this stream. The overall probabilistic risk of cypermethrin to aquatic species in Chebei Creek reached 66% when acute-to-chronic ratios were set at 125. An exceedance probability of cypermethrin in Chebei Creek that affected H. azteca as modeled using the joint probability curve method was 88%, suggesting that most sites were at risk due to cypermethrin exposure. This value was similar to the results obtained from acute toxicity tests (71% of field water samples were acutely toxic to H. azteca), indicating the effectiveness of the tiered approach to assess risk of cypermethrin in urban waterways. To the authors' knowledge, the present study is the first to provide a focused probabilistic evaluation of ecological risk for cypermethrin in a complex urban waterway environment. Despite uncertainties existing in the ecological risk assessment procedure, this approach provides a comprehensive assessment of ecological risk of cypermethrin, and subsequently, a foundation for further risk diagnosis and management in urban waterways.
采用分层生态风险评估方法对拟除虫菊酯类杀虫剂氯氰菊酯对水生生物的总体概率风险进行定量细化。然后，利用中国南方广州城区一条溪流车陂涌的现场水样进行生物测定，对这些结果进行验证。沿车陂涌采集了17个水样进行评估。总体而言，71%的现场水样对阿氏摇蚊具有急性毒性，24%的水样导致100%的死亡率。毒性单位评估表明，氯氰菊酯是毒性的主要贡献者之一。分层生态风险评估方法（确定性商数法和概率方法，包括联合概率曲线和蒙特卡罗模拟）表明，氯氰菊酯对这条溪流的水生生态构成重大威胁。当急性-慢性比率设定为125时，氯氰菊酯对车陂涌水生物种的总体概率风险达到66%。使用联合概率曲线法模拟得出，车陂涌中影响阿氏摇蚊的氯氰菊酯超标概率为88%，这表明大多数地点因接触氯氰菊酯而面临风险。该值与急性毒性试验结果相似（71%的现场水样对阿氏摇蚊具有急性毒性），表明分层方法在评估城市水道中氯氰菊酯风险方面的有效性。据作者所知，本研究首次对复杂城市水道环境中氯氰菊酯的生态风险进行了重点概率评估。尽管生态风险评估程序存在不确定性，但该方法提供了对氯氰菊酯生态风险的全面评估，随后为城市水道的进一步风险诊断和管理奠定了基础。
