A Study on the Distribution Characteristics of Microplastics in the Atmosphere Using Spectroscopic Analysis

Abstract

In this study, microplastics in atmospheric fine dust were isolated based on size and subsequently identified using μ-Raman. First, fine dust was collected using a high-volume air sampler with a stainless-steel (STS) filter; the STS filter, made of stainless steel of 1 μm pore size, was used in place of a traditional quartz filter. Particles collected by the filter were separated by gravity, followed by oxidation of the organic matter. The pretreated samples were refiltered using a silicon filter, followed by the identification of microplastics using μ-Raman. The collected air samples had 2.5 ± 2.0 (0.6-7.6) MPs/m3. The most detected material was polyethylene (64%), followed by nylon (20%), polyethylene terephthalate (5%), polystyrene (5%), and polypropylene (2%). The average size of the detected microplastics was 13.1 ± 9.0 (1.7-107.4) μm. The cumulative percentages show that particles 30 μm and smaller account for 96% of the total, 20 μm and smaller for 82%, and 10 μm and smaller for 46%. It was observed that microplastic abundance (MPs/m³) by date was not significantly correlated with precipitation or PM10.