We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Urban road dust as a dynamic reservoir for microplastics: Quantifying precipitation washout, recovery patterns, and traffic influence in Bahía Blanca, Argentina
Summary
Researchers tracked microplastics in urban road dust in Argentina before and after a 26 mm rainfall event, finding that paved surfaces lost 44% of accumulated particles while unpaved surfaces shed only 14%, and that tire wear particles dominated paved roads while fibers prevailed on unpaved surfaces — demonstrating that surface type and driving behavior, not just traffic volume, govern how MPs are mobilized and transported to nearby estuaries.
Microplastics in urban road dust remain poorly understood in South America. This study investigated microplastic dynamics in Bahía Blanca, Argentina, examining precipitation effects, surface type, and traffic influence over three days (n = 30 samples). Particles (1-5000 μm) were recovered through density separation (1.2 g/cm NaCl solution), with visual identification limited to particles ≥50 μm using stereomicroscopy, supplemented by ATR-FTIR and micro-Raman spectroscopy for polymer characterization. Microplastics were detected in 100% of samples from paved and unpaved roads, with mean concentrations of 1,526 ± 795 MP/kg. A 26 mm precipitation event mobilized 31.9% of accumulated particles, with marked differences between paved surfaces (43.5% washout, 50.9% recovery) and unpaved surfaces (13.5% washout, 5.2% recovery), demonstrating surface-specific particle mobility. Morphological analysis revealed distinct contamination sources: tire wear particles (TWP) dominated paved roads (37.2%), while fibers prevailed on unpaved surfaces (67.9%). The non-linear relationship between traffic and TWP distribution-with a low-traffic parking area (26 vehicles/hour) showing higher TWP proportions (60.3%) than high-traffic sites (1,784 vehicles/hour, 36.4%)-reveals that local generation-resuspension balance depends on driving patterns and atmospheric conditions rather than traffic volume alone. Spectroscopic identification confirmed common polymers (PET, PP, PE, PA) and textile-associated pigments (copper phthalocyanine 32.8%, indigo 10.0%). The 250-500 μm size fraction (21.6% of particles) represents particular concern for resuspension and transport. Results demonstrate that urban dust operates as a dynamic microplastic reservoir, mobilized through hydrological and atmospheric pathways, with implications for stormwater management and estuarine pollution, as road dust particles are ultimately transported to the Bahía Blanca Estuary through precipitation runoff.