Abstract：
Neonicotinoid pollution has increased rapidly and globally in recent years, posing significant risks to agricultural areas. Quantifying use and emission, transport and fate of these contaminants, and risks is critical for proper management of neonicotinoids in river basin. This study elucidates use and emissions of neonicotinoid pesticides in a typical large-scale agriculture basin of China, the Pearl River Basin, as well as the resulting agricultural non-point source pollution and related ecological risks using market surveys, data analysis, and the Soil and Water Assessment Tool. Neonicotinoid use in the basin was estimated at 1361 t in 2019, of which 83.1 % was used in agriculture. After application, approximately 99.1 t neonicotinoids were transported to the Pearl River, accounting for 7.2 % of the total applied. Estimated aquatic concentrations of neonicotinoids showed three seasonal peaks. Several distinct groups of neonicotinoid chemicals can be observed in the Pearl River, as estimated by the model. An estimated 3.9 % of the neonicotinoids used were transported to the South China Sea. Based on the present risk assessment result, several neonicotinoids posed risks to aquatic organism. Therefore, the use of alternative products and/or reduced use is deemed necessary. This study provides novel insights into the fate and ecological risks of neonicotinoid insecticides in large-scale watersheds, and underscores the need for greater efficiency of use and extensive environmental monitoring.
摘要：
近年来，新烟碱污染在全球范围内迅速增加，对农业领域构成重大风险。量化使用和排放，这些污染物的运输和命运，风险对于正确管理流域的新烟碱至关重要。这项研究阐明了新烟碱类农药在中国典型的大规模农业流域的使用和排放，珠江流域,以及由此产生的农业面源污染和相关生态风险，数据分析,以及土壤和水评估工具。据估计，2019年该流域新烟碱的使用量为1361吨，其中83.1％用于农业。申请后,大约99.1吨新烟碱被输送到珠江，占申请总数的7.2%。新烟碱的估计水生浓度显示出三个季节性峰值。在珠江可以观察到几种不同的新烟碱化学物质，根据模型估计。估计有3.9％的新烟碱被运送到南中国海。根据目前的风险评估结果，几种新烟碱对水生生物构成风险。因此,使用替代产品和/或减少使用被认为是必要的。这项研究为大型流域新烟碱类杀虫剂的命运和生态风险提供了新的见解，并强调需要提高使用效率和广泛的环境监测。
