Investigations of marine microplastic pollution, effects of weathering on microplastic chemical identification, and development of computer vision tools to facilitate microplastic studies

Abstract

Plastic-waste leakage is a major unintended consequence of plastic usage and consumption. Plastic waste is a long-term environmental challenge and global concern that inspires increasing efforts to prevent further pollution and understand the impact of plastic pollution on the environment. Microplastic identification is a necessary first step in investigating the harmful effects in the environment and efforts have been made to characterize the types of microplastics in marine organisms inhabiting the Salish Sea and Gulf of Alaska. Unfortunately, no single analytical approach is flawless in determining the identity of microparticles and studies on the chemical transformation of microplastics is a must. Environmentally weathered microplastics can differ significantly from their un-weathered counterparts which the identification of microplastics. It was found that weathering conducted with Puget Sound seawater show different weathering byproducts compared to other simulated environments. This implies that studies with environmental water is needed to further understand degradation mechanisms and microplastic pollution effects. Despite this, Raman spectroscopy retains great fidelity of weathered polymer spectra and show little variation with increasing exposure to sunlight and may serve as a more accurate and versatile tool for microplastic identification compared to IR spectroscopy. While these tools are helpful, computer vision and machine learning have significant potential to recognize morphological features to classify the shape of microplastics <100 µm, further advancing the microplastic field.