Lotz Tom, Chen Wenjun, Su Shoubao
School of Computer Engineering, Jinling Institute of Technology, Hongjing Avenue 99, Nanjing 211169, China.
Jiangsu Key Laboratory of Data Science & Smart Software, Jinling Institute of Technology, Hongjing Avenue 99, Nanjing 211169, China.
Toxics. 2024 Oct 19;12(10):761. doi: 10.3390/toxics12100761.
Microplastic (MP) pollution in agricultural ecosystems is an emerging environmental concern, with limited knowledge of its transport and accumulation in rural waterbodies. This study investigates the distribution and sources of MP in drainage ditches influenced by pond connectivity, land use, and soil properties within a small catchment in Nanjing, East China. Sediment was collected from ditches in 18 sites across forest, agricultural, horticultural, and urban areas. Using laser-directed infrared spectroscopy (LDIR), 922 MP particles were identified. Six materials were dominant: fluororubber (FR), polyethylene terephthalate (PET), polyurethane (PU), acrylonitrile (ACR), chlorinated polyethylene (CPE), and polyethylene (PE). MP concentrations varied by land use and pond connectivity, with ditches above ponds exhibiting higher counts (1700 particles/kg) than those below (1050 particles/kg), indicating that ponds act as MP sinks. The analysis revealed site-specific MP sources, with FR linked to road runoff and PET associated with agricultural practices. Correlations between MP shape and soil properties showed that more compact and filled shapes were more commonly associated with coarser soils. PE particle size was negatively correlated with organic matter. This study highlights the need for targeted strategies to reduce MP pollution in rural landscapes, such as reducing plastic use, ditch maintenance, and improved road runoff management.
农业生态系统中的微塑料（MP）污染是一个新出现的环境问题，人们对其在农村水体中的迁移和积累了解有限。本研究调查了中国东部南京市一个小流域内受池塘连通性、土地利用和土壤性质影响的排水沟中微塑料的分布和来源。从森林、农业、园艺和城市地区的18个地点的沟渠中采集了沉积物。使用激光导向红外光谱（LDIR）识别出922个微塑料颗粒。六种材料占主导地位：氟橡胶（FR）、聚对苯二甲酸乙二酯（PET）、聚氨酯（PU）、丙烯腈（ACR）、氯化聚乙烯（CPE）和聚乙烯（PE）。微塑料浓度因土地利用和池塘连通性而异，池塘上方的沟渠中微塑料数量（1700个颗粒/千克）高于下方的沟渠（1050个颗粒/千克），这表明池塘起到了微塑料汇的作用。分析揭示了特定地点的微塑料来源，氟橡胶与道路径流有关，聚对苯二甲酸乙二酯与农业活动有关。微塑料形状与土壤性质之间的相关性表明，更致密和填充的形状更常与较粗的土壤相关。聚乙烯颗粒大小与有机质呈负相关。本研究强调需要采取针对性策略来减少农村景观中的微塑料污染，如减少塑料使用、沟渠维护和改善道路径流管理。
