单甲甲酸盐 (MSMA) 的环境命运-第二部分:模拟封存和转化
W Martin Williams1, J Mark Cheplick1, Stuart Z Cohen2
1Waterborne Environmental, Inc., Leesburg, Virginia, USA.
Integrated environmental assessment and management
|June 26, 2024
概括
使用单甲 (MSMA) 除草剂可能导致饮用水中低水平的无机 (iAs). 估计的度仍然低于监管关注,即使广泛应用,由于土壤封存过程.
科学领域:
- 环境化学环境化学
- 土壤科学 土壤科学
- 生态毒理学 生态毒理学
背景情况:
- 单甲 (MSMA) 是一种广泛使用的除草剂.
- 在水中,MSMA分解为和单甲基酸盐 (MMA).
- 在土壤中,MMA经历微生物转化,包括甲基化和脱甲基化,以及吸附到土壤矿物质中.
研究的目的:
- 为了估计MSMA使用导致的饮用水中的无机 (iAs) 度.
- 用美国环保署农药风险评估模型和场景来评估潜在风险.
主要方法:
- 在30年的模拟期内,对IA的建模饮用水度 (EDWCs).
- 每年在标签上使用的最大标签率上应用MSMA.
- 考虑的场景包括总合适的经过处理的土地和实际经过处理面积的高估计.
主要成果:
- 估计的饮用水度 (EDWC) iAs在所有合适的土地被处理时从<0.001到0.12μg/L不等.
- 在所有情景中,当考虑对待面积的高估计时,EDWCs低于0.06μg/L.
- 土壤封存迅速使MSMA代谢物固定,限制了它们的生物可用性.
结论:
- 应用MSMA不太可能导致饮用水受到iAs的严重污染.
- 土壤过程有效地限制了对MSMA代谢物的环境暴露.
- 估计的IA水平远低于监管关注的水平.
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