Are northern communities an overlooked source of microplastics and tire wear particles in the Arctic?

Abstract

Microplastic particles (plastic 1 µm to 5 mm in length) are a contaminant of emerging concern in Arctic environments; nonetheless, few studies have evaluated atmospheric microplastics in Arctic communities. This study investigated microplastics and tire wear particles across 16 sites in the community of Iqaluit, Nunavut (population = 7,429) using road dust as an indicator of atmospheric microplastic deposition (size detection limit >50 µm). The mean concentration of microplastics (excluding tire wear particles), ranged from 36.5 ± 68.4 µg/g (5.41 ± 4.69 n/g) in industrial sites and 73.4 ± 121 µg/g (6.21 ± 4.46 n/g) in commercial sites and non-fibrous microplastics (i.e., fragments, films, and foams) were dominant across the study area. Various polymers were identified using Fourier-Transform Infrared spectroscopy in Attenuated Total Reflectance down to a particle size of 100 µm. The dominant polymers being polyethylene terephthalate (15%), polyester (15%), polymethyl acrylate (15%), and polystyrene (15%). Further, based on the results of the microplastic diversity integrated index, commercial and industrial regions were composed of unique microplastic communities. The mean concentration of tire wear particles (dominated by rubber; 27%) in road dust was significantly greater than other microplastics, ranging from 83.2 ± 49.1 µg/g (49.3 ± 30.0 n/g) in industrial sites to 481 ± 514 µg/g (102 ± 132 n/g) in commercial sites. The concentration of microplastics and tire wear particles in Iqaluit was consistent with observations from metropolitan cities, suggesting Arctic communities may be a substantial local source of atmospheric microplastics and tire wear particles to surrounding Arctic ecosystems.