三唑酮在水环境中的环境行为、毒性效应及生态风险

三唑酮是目前应用最广泛的三唑类广谱杀菌剂之一,在我国的使用量有逐年增长的趋势。本研究综述了三唑酮在水环境中的环境行为、毒性效应及其对我国部分水体的生态风险。三唑酮使用后被土壤吸附和解吸,经雨水淋溶作用进入地表或地下水环境,在丰水期检出率与检出浓度较高,目前我国地表水中三唑酮最高检出浓度为12μg·L-1。三唑酮在环境中的半衰期为15~43.3 d,能够在水生生物体内累积代谢,在不同浓度下对不同类群、不同生命阶段的水生生物表现出不同的毒性效应,对应着多条有害结局路径,其中最重要的是通过抑制细胞色素P450酶活性干扰机体内激素水平,影响水生生物繁殖和生长发育,导致种群密度降低。在目前已知的暴露水平下,三唑酮对我国地表水具有潜在的生态风险,特别是丰水期稻田附近的地表水风险尤其需要关注。

Review of Environmental Behavior, Toxicity and Ecological Risk of Triadimefon in the Aquatic Environment

Triadimefon is a broad-spectrum, systemic fungicide, belonging to the triazole family. With adjustment of the national policy and agricultural planting structure, usage of triadimefon in China has been increasing annual-ly. In present review, the environmental behavior, ecotoxicity and ecological risk of triadimefon are discussed in Chinese surface waters. With the solubility of triadimefon, residues desorbed from soil can be transported by rain to surface or groundwater. Concentrations of triadimefon in surface water in China as great as 12 μg L-1 , and with higher detected rate and concentration in wet season. Triadimefon with half life of 15~43.3 days in environment, it would accumulate persistently in the water environment and cause adverse effect to aquatic organisms due to its consistency and adsorption. Long-term exposure of aquatic organisms to triadimefon has potential to disrupt devel-opment or reproduction and can cause malformations that adversely affect fitness and survival of juveniles although the mechanisms are unclear. The most important adverse outcome pathways (AOP) was that disrupting hormone level by inhibiting enzyme activity of cytochrome P450, and then impacting organisms reproduction, growth and development which reducing population density lastly. Potential deleterious effects and hazards or risks of exposure of aquatic organisms from current patterns of use of triadimefon in surface water if of concern, especially for waters near rice field in wet season.