Background

Glyphosate is a broad-spectrum, non-selective systemic herbicide with a commonly assumed low potential for accumulation in biota. Nevertheless, glyphosate has been shown to bioaccumulate in the tissues of several organisms. To understand the bioconcentration dynamics of glyphosate in fish, brown trout (Salmo trutta forma fario) of different age were exposed to different concentrations of glyphosate, the formulation Roundup® LB Plus, and the major transformation product aminomethylphosphonic acid (AMPA) for two, three, or four weeks at different temperatures in the laboratory. Mortality rates were determined, and tissue samples were collected at the end of the experiment to ascertain concentrations of glyphosate and AMPA residues by liquid chromatography coupled to mass spectrometry (LC–MS/MS).

Results

Brown trout mortality during exposure to glyphosate or AMPA was considerably higher at 15 °C than at 7 °C. Also, a significant increase in glyphosate concentrations in samples containing muscle, head, backbone, and caudal fin tissue with increasing exposure concentrations and temperatures was observed. Six-month-old fish contained more glyphosate per kg wet weight after exposure than ten-month-old fish. The bioconcentration factors (BCFs) for glyphosate and AMPA were much higher at 15 °C than at 7 °C, but in both cases decreased with higher glyphosate concentrations. The BCF for glyphosate formulated in Roundup® was higher than the one for the parent compound. Approximately 30–42% of the organ-absorbed glyphosate and AMPA remained in the tissues even when the fish were kept in clean water lacking the test substances for three weeks after termination of exposure.

Conclusion

Our study demonstrated that there is an interaction between glyphosate and ambient temperature in terms of toxicity. Further it was shown that increasing concentrations of glyphosate and AMPA in the surrounding media lead to significantly increased concentrations of these substances in brown trout tissues, although neither bioconcentration nor bioaccumulation of glyphosate in animal tissues is expected due to the high water solubility of this chemical. As a consequence, the uptake of glyphosate by humans through the consumption of contaminated edible fish is very likely.

中文翻译：

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暴露在不同温度下的草甘膦和氨甲基膦酸 (AMPA) 引起的褐鳟幼鱼 (Salmo trutta f. fario) 的死亡率和残留

背景

草甘膦是一种广谱、非选择性内吸性除草剂，通常认为在生物群中积累的可能性较低。然而，草甘膦已被证明会在几种生物体的组织中生物蓄积。为了了解草甘膦在鱼类体内的生物富集动态，将不同年龄的褐鳟鱼（Salmo trutta forma fario）暴露于不同浓度的草甘膦、配方 Roundup® LB Plus 和主要转化产物氨甲基膦酸 (AMPA) 中，观察 2、3 小时。 ，或在实验室的不同温度下四个星期。确定死亡率，并在实验结束时收集组织样本，通过液相色谱-质谱联用 (LC-MS/MS) 确定草甘膦和 AMPA 残留物的浓度。

结果

暴露于草甘膦或 AMPA 期间，15 °C 下的褐鳟死亡率明显高于 7 °C 下的死亡率。此外，随着暴露浓度和温度的增加，含有肌肉、头部、脊椎和尾鳍组织的样品中的草甘膦浓度显着增加。接触后六个月大的鱼每公斤湿重中的草甘膦含量高于十个月大的鱼。草甘膦和 AMPA 的生物浓缩因子 (BCF) 在 15 °C 时比在 7 °C 时高得多，但在两种情况下都随着草甘膦浓度的升高而降低。 Roundup® 中配制的草甘膦的 BCF 高于母体化合物。即使在停止接触后将鱼放在缺乏测试物质的干净水中三周，大约 30-42% 的器官吸收的草甘膦和 AMPA 仍保留在组织中。

结论

我们的研究表明，草甘膦和环境温度之间在毒性方面存在相互作用。此外，研究还表明，周围介质中草甘膦和 AMPA 浓度的增加会导致褐鳟组织中这些物质的浓度显着增加，尽管由于这种化学物质的高水溶性，预计动物组织中的草甘膦不会发生生物富集或生物累积。因此，人类很可能通过食用受污染的食用鱼而摄入草甘膦。