oa Comprehensive Analysis of Microplastic Fragmentation and Aging in the Marine Environment

Microplastic (MP) contamination is a growing concern, which gained attention in the research world due to their persistence and adverse impact on the environment. Understanding MPs fragmentation and aging is crucial for assessing environmental impacts and toxicity. However, standardized methods for quantifying MPs degradation are still not adequate. This study proposes an approach to analyze fragmentation and aging of MPs in marine environments using thermal Rock-Eval® signals to identify degradation patterns. Additional measurements were performed (EA-IRMS, FTIR, Raman spectroscopy, and weight loss) to investigate several parameters (Total HC, TOC, d13C, and bond indices) as a function of exposure time. To simulate degradation in marine environments, a seawater microcosm experiment was conducted using commercial polymer pellets (PE, PET, and PLA) and a degraded PE film from a French landfill for one year. Artificially degraded samples aged for ten years in the seawater microcosm and naturally degraded pellet samples retrieved from the Pacific Ocean were also analyzed for comparison. Results indicate minimal fragmentations within a year. Nevertheless, both chemical and structural changes were observed varying based on polymer type. These findings contribute to a better understanding of MPs degradation, aiding future environmental assessments and potential mitigation strategies.