城市大气微塑料沉降的空间格局与短期变化
Spatial patterns and short-term deposition of atmospheric microplastics in an urban environment
Spatial patterns and short-term deposition of atmospheric microplastics in an urban environment
来自南非和意大利的研究人员调查了南非东开普省马坎达镇不同土地利用类型区域的大气微塑料沉降特征及其与气象因素的关系。
大气沉降正成为微塑料从污染源向陆地和水体迁移的重要途径，但在南部非洲等发展中地区，关于大气微塑料沉降、短期波动和气象影响的研究仍然不足。研究人员在城市区、城郊高密度居住区和半自然区设置三个采样点，连续六周开展每周24小时被动沉降采样，并利用显微镜观察、傅里叶变换红外光谱-衰减全反射（FTIR-ATR）鉴定和统计分析评估微塑料通量、形态、颜色、粒径、聚合物类型及其与降雨等气象变量的关系。结果显示，三个站点均检出大气微塑料，平均沉降通量为86.5 ± 10.4 个/m²/day，城郊区最高、半自然区最低，主要形态为纤维/丝状物（95.5%），主要聚合物为PET（42.5%）。研究认为，当地大气微塑料沉降呈明显空间差异，可能与土地利用、人类活动、废物管理、污水渗漏和纺织相关来源有关，且城市点位微塑料沉降与降雨呈正相关。未来研究应开展更长期、季节性和标准化监测，并结合风向、后向轨迹、排放清单和主动采样方法，以更准确识别来源并支撑南部非洲城市化地区的塑料污染管理。
此篇名为《Spatial patterns and short-term deposition of atmospheric microplastics in an urban environment》的文章发表于2026年6月的《Scientific Reports》期刊。
Researchers from South Africa and Italy investigated atmospheric microplastic deposition characteristics across areas with diverse land-use types in Makhanda, Eastern Cape Province, South Africa, as well as their correlations with meteorological factors.
The abstract is as follows:
Atmospheric deposition is an important and newly recognised pathway for microplastics (MPs), influencing their transportation and distribution both on land and in aquatic environments. However, MP pollution in the air remains relatively understudied compared to aquatic environments, particularly in developing regions such as Southern Africa. Despite the growing body of literature on MPs in Southern Africa, studies investigating atmospheric MP deposition, short-term variability, and links with meteorological conditions remain limited. This study investigates the occurrence and characteristics of atmospheric MP deposition and their relationship with meteorological factors within an urban town in the Albany thicket biome of South Africa, using weekly sampling over a six-week period across three sites associated with different land-use types. MP deposition fluxes were found to be significantly different between study sites, with an average of 86.5 ± 10.4 particles/m²/day. The highest deposition fluxes were recorded at S2, located in a peri-urban area (178.1 ± 69.2 particles/m²/day) ~ 4.5 km from the town center, while the lowest were observed at S3, ~ 10 km outside the town in a semi-natural area (24.7 ± 8.2 particles/m²/day). Around 30.2% of MPs identified had particle sizes between ≥ 250 and < 500 μm. The dominant colour was transparent/clear (46.6%) and the prevalent shape was fibre/filament (95.5%). FTIR-ATR analysis revealed that polyethylene terephthalate (PET) was the predominant polymer type (42.5%). Microplastic deposition fluxes at S1 (urban area) showed a positive correlation with rainfall, suggesting that rainfall likely influences local MP deposition dynamics at this site. Microplastic deposition fluxes in the town are likely influenced by a combination of local pollution sources, including sewage seepage, poor waste disposal, wastewater management, and textile-related activities. These findings demonstrate clear spatial variation in atmospheric MP deposition linked to land use and local anthropogenic activities, emphasising the importance of atmospheric pathways in regional plastic pollution cycling. The study highlights an urgent need to incorporate atmospheric MPs into environmental monitoring and waste management policies, particularly in urbanising regions of Southern Africa where regulatory frameworks and baseline datasets are still emerging.