Fine micro- and nanoplastics concentrations in particulate matter samples from the high alpine site Sonnblick, Austria

Abstract

We report atmospheric fine micro- and nanoplastics concentrations from particulate matter (PM) samples of two size fractions (PM₁₀, fine micro- and nanoplastics, and PM₁, nanoplastics), which were collected at the remote high alpine station Sonnblick Observatory, Austria. Active sampling was performed from June 2021 until April 2022. Analysis was done using TD-PTR-MS to detect 6 different plastic types. Polyethylene terephthalate (PET), polyethylene (PE) and polypropylene/polypropylene carbonate (PP/PPC) were found to be the dominating species. PET was detected in almost all samples, while the other plastic types occurred more episodically. Furthermore, polyvinyl chloride (PVC), polystyrene (PS) and tire wear particles were detected in single samples. Considering the three main plastic types, average plastics concentrations were 35 and 21 ng m^-³ with maximum concentrations of 165 and 113 ng m^-³ for PM₁₀ and PM₁, respectively. Average polymer concentrations were higher in the summer/fall period than in winter/spring. In summer/fall, PM₁₀ plastics concentrations were higher by a factor of 2 compared to PM₁, while concentrations of both size classes were comparable in the winter/spring period. This suggests that in the colder season plastic particles arriving at the Eastern Alpine crests are mainly present as nanoplastics. The contribution of micro- and nanoplastics to organic matter at the remote site was found to be comparable to data determined at an urban site. We found significant correlations between the PET concentration and tracers originating from anthropogenic activities such as elemental carbon, nitrate, ammonium, and sulphate as well as organic carbon and arabitol.

Keywords: High alpine environment; Microplastics; Mineral dust; Nanoplastics; Particulate matter.