State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen, Guangdong 518055, China.
Environ Sci Technol. 2022 May 17;56(10):6243-6252. doi: 10.1021/acs.est.1c07825. Epub 2022 Apr 28.
We developed a regional atmospheric transport model for microplastics (MPs, 10 μm to 5 mm in size) over Asia and the adjacent Pacific and Indian oceans, accounting for MPs' size- and shape-dependent aerodynamics. The model was driven by tuned atmospheric emissions of MPs from the land and the ocean, and the simulations were evaluated against coastal ( = 19) and marine ( = 56) observations. Our tuned atmospheric emissions of MPs from Asia and the adjacent oceans were 310 Gg y (1 Gg = 1 kton) and 60 Gg y, respectively. MP lines and fragments may be transported in the atmosphere >1000 km; MP pellets in our model mostly deposited near-source. We estimated that 1.4% of the MP mass emitted into the Asian atmosphere deposited into the oceans via atmospheric transport; the rest deposited over land. The resulting net atmospheric transported MP flux from Asia into the oceans was 3.9 Gg y, twice as large as a previous estimate for the riverine-transported MP flux from Asia into the oceans. The uncertainty of our simulated atmospheric MP budget was between factors of 3 and 7. Our work highlighted the impacts of the size and morphology on the aerodynamics of MPs and the importance of atmospheric transport in the source-to-sink relationship of global MP pollution.
我们开发了一个亚洲及周边太平洋和印度洋地区的大气传输模型，用于模拟微塑料（粒径 10μm 至 5mm 的塑料颗粒）的传输过程，该模型考虑了微塑料的尺寸和形状对空气动力学的影响。模型的驱动力是陆地和海洋中经过调整的微塑料排放，通过对 19 个沿海点和 56 个海洋点的观测数据进行了评估。经调整后，我们模拟的亚洲和周边海洋地区的大气微塑料排放量分别为 310 万吨/年和 60 万吨/年。微塑料线和碎片可能在大气中传输超过 1000 公里；而在我们的模型中，微塑料颗粒主要在源附近沉积。我们估计，有 1.4%的排放到亚洲大气中的微塑料质量通过大气传输沉积到海洋中，其余则沉积在陆地上。由此产生的亚洲向海洋的净大气传输微塑料通量为 3.9 万吨/年，是此前亚洲河流向海洋输送微塑料通量估计值的两倍。我们模拟的大气微塑料预算的不确定性在 3 到 7 倍之间。我们的研究强调了微塑料尺寸和形态对其空气动力学的影响，以及大气传输在全球微塑料污染源汇关系中的重要性。
