Characteristics, sources and influencing factors of atmospheric deposition of microplastics in three different ecosystems of Beijing, China

As the research on microplastics (MPs) has intensified, more attention has been paid to MPs deposition in the atmosphere. This study further explores and compares the characteristics, the possible sources and influencing factors of deposition of MPs in three different ecosystems: forest, agricultural and residential area in Beijing. It was found that the deposited plastics were mostly white or black fibres, with PET and RY as the main MPs types. The range of deposition fluxes was 67.06-461.02 item·m·d, with highest deposition in residential area and lowest in forest, significant differences in MPs characteristics between environments. Based on MPs composition and shape, combined with backward trajectory analysis, the main sources of MPs were found to be textiles. Deposition of MPs was found to be influenced by environmental and meteorological factors. Factors such as gross domestic product and population density had a significant impact on the deposition flux, while wind played a diluting role for atmospheric MPs. The study investigated the characteristics of MPs in different ecosystems which may help to understand the transport patterns of MPs and is of great importance for the management of MPs pollution.