As the amount of environmentally exposed plastics increase rapidly, microplastics (MPs) have attracted considerable concerns as pollutants and potentially toxic substances to the ecosystem and human beings. Previous research has brought up the threat of fragmentation and surface change by eco-corona or weathering can occur severe damage to the human being. Despite the importance of plastic's fragmentation, the influence of the weathering and physiological environment on the fragmentation behavior has not been clearly investigated. Here, we demonstrated a comprehensive study for the effect of weathering and physiological environment on the fragmentation pattern of plastics. We selected polyvinyl chloride (PVC), acrylonitrile butadiene styrene copolymer (ABS), and polystyrene (PS) as the representative plastics to test. Firstly, to simulate weathering factors, we exposed the plastics to UV light and seawater after treatment of accelerated thermal aging. For exposure to the physiological environment, we imitate the gastrointestinal organ following the simple digestion solution method. After exposure to each condition, we characterized the surface of plastics by scanning electron microscope, infrared spectroscopy, and x-ray photoelectron spectroscopy. We investigated the crystalline structure change by atomic force microscopy. Since we assumed the micronization behavior of plastics is highly dependent on the amorphous structure of plastics, we confirmed the crystalline and amorphous parts of each sample. After the fragmentation of plastics by ball-milling, we analyzed the size distribution and shape of microplastics. The randomized amorphous part of plastics induced a smaller size distribution compared to the linearly aligned amorphous part. With the size and shape analysis of exposed MPs, we confirmed the cellular uptake rate and immune cytokines release correlated to each environmentally exposed plastic. Our findings suggest that the study for potential toxicity of MPs should undergo via the understanding of the micronization behavior of plastics.

Influence of environmental and physiological exposure on the fragmentation behavior and surface characteristics change of microplastic inducing potential toxicity

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.