Microplastics in a Southern Appalachian Forest

<span style="font-weight: 400;">Microplastics are ubiquitous emerging contaminants, yet there is a lack of knowledge concerning how they enter and impact rural terrestrial ecosystems. To address this gap, we analyzed microplastics in bycatch wild shrews, earthworms (a common food source for shrews), and atmospheric deposition samples collected in a Southern Appalachian forest. To assess the possibility of trophic transfer, bioaccumulation, and the extent to which airborne microplastics become incorporated into this terrestrial ecosystem, we compared microplastic concentrations in shrew and earthworm tissues, examined potential differences in microplastic concentration across shrew organs, and looked for similarities in microplastic type and color between shrew, earthworm, and atmospheric deposition samples. Tissues of earthworms and shrews organs (heart, liver, kidney, gut, lungs, brain) were dissolved with hydrogen peroxide, filtered, and examined under a microscope. A subset of samples was analyzed using Raman Spectroscopy technology to assess whether particles were correctly identified as plastic. We found that shrews had higher microplastic concentrations per gram of tissue than earthworms, that shrew hearts had highest microplastic concentrations, and similar colors and types of microplastics across sample types. Given the growing consensus that microplastics endanger organism health, we advocate for use of the precautionary principle in regards to microplastic pollution.</span>