Background

Imidacloprid is an active ingredient included in plant protection, biocidal and veterinary medicinal products (VMPs). VMPs containing Imidacloprid are formulated as spot-on products or collars and designed to protect pets, predominantly dogs and cats, from parasite infestation. Monitoring data collected under the Water Framework Directive between 2016 and 2018 showed detectable and varying levels of Imidacloprid in the UK surface water bodies. The aim of the work was to investigate the potential contribution of VMPs by developing a model for predicting the emissions from sewage treatment plants from the use of dog and cat spot-on and collar VMPs. Due to the absence of appropriate exposure models for VMPs, the model was built based on the principles of environmental exposure assessment for biocidal products.

Results

Three emission paths were considered to be the most likely routes for repeated emissions to waterways from the use of spot-on and collar VMPs, i.e., transfer to pet bedding followed by washing, washing/bathing of dogs, and walking dogs in the rain. The developed model was used to calculate the Imidacloprid concentrations in surface water after discharge from wastewater treatment plants. Realistic worst-case input parameters were deduced from sales and survey data and experimental studies. Modelled total concentrations in surface water for each pathway ranged from 0.84 to 4.8 ng/L. The calculated concentrations did not exceed the ecological thresholds for the most sensitive aquatic invertebrate organisms and were found to be much lower than the UK monitoring data for river water. For example, the calculated concentration from the bathing/washing of dogs was < 3% of the highest levels of Imidacloprid measured in surface waters.

Conclusion

In conclusion, a model has been successfully built and applied. The modelled data indicate that these VMPs make only a very small contribution to the levels of Imidacloprid observed in the UK water monitoring programme. Further, calculated concentrations do not exceed ecotoxicological threshold values indicating acceptable chronic safety to aquatic organisms.

中文翻译：

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兽药使用引起的污水处理厂排放中吡虫啉的水生暴露评估模型的开发

背景

吡虫啉是植物保护，杀菌和兽药（VMPs）中包含的活性成分。含有吡虫啉的VMP被配制为即用产品或项圈，旨在保护宠物（主要是狗和猫）免受寄生虫侵扰。根据2016年至2018年《水框架指令》收集的监测数据显示，英国地表水体中吡虫啉的含量可检测且变化不定。该工作的目的是通过开发模型来预测VMP的潜在贡献，该模型可通过使用狗和猫的斑点VMP和项圈VMP来预测污水处理厂的排放。由于缺乏适用于VMP的适当暴露模型，因此该模型是根据杀生物产品的环境暴露评估原则建立的。

结果

三种排放路径被认为是使用点状和颈圈式VMP反复排放到水道的最可能途径，即转移到宠物床上用品，然后洗狗，洗狗/洗澡以及在雨中walking狗。所开发的模型用于计算废水处理厂排放后地表水中吡虫啉的浓度。实际的最坏情况输入参数是根据销售和调查数据以及实验研究得出的。每个路径的地表水中模拟总浓度范围为0.84至4.8 ng / L。计算出的浓度未超过最敏感的水生无脊椎动物生物的生态阈值，并且发现其浓度远低于英国对河水的监测数据。例如，

结论

总之，已成功建立并应用了模型。建模数据表明，这些VMP对英国水监测计划中所观察到的吡虫啉水平仅贡献很小。此外，计算出的浓度不超过生态毒理学阈值，表明对水生生物可接受的长期安全性。