Identification and Quantification of Microplastics (MPs) in the Precipitation of Faribault City in Minnesota

Abstract

As one of the most successful synthetic materials, plastics have been produced at an exponential rate since its invention in the 1950s. Due to its strong durability, most disposed plastics can stay in the environment for a long time and experience degradation into microplastic particles (<5mm). Small microplastics particles have been found in fish, indicating seafood as a source of ingesting plastics; other studies have found atmospheric deposition as another potential microplastics particle transport route, as microplastics particles have been found in rain in many European cities and in some states in the US. Yet, there have been none trying to find microplastic particles present in precipitation in Minnesota. This study discovered the presence of microplastics in the rainwater in Faribault, a southern Minnesota city. The rain and snow was collected over night; photos and µ-Raman Spectroscopy graphs were taken for detailed analysis. Specifically, fibers and acrylic fragments (Type 1; Type 7) were present in the rain sample; no microplastic particles were found in the snow sample. The concentration of microplastic particles in the rain sample is approximately 75.34 particles m-2 d-1, comparable to the concentration reported in other studies.