Nanoplastics Weathering and Polycyclic Aromatic Hydrocarbon Mobilization

Abstract

Despite increasing efforts to recycle plastic materials, large quantities of plastics waste continue to accumulate in the oceans. Persistent mechanical and photochemical degradation of plastics in the oceans yields micro-and nanoscale plastic particles, which represent potential vectors for mobilizing hydrophobic carcinogens in an aqueous milieu. Yet, the fate and potential threats associated with plastics remain largely unexplored. Herein, we apply an accelerated weathering protocol to consumer plastics to characterize the effect of photochemical weathering on the size, morphology, and chemical composition of nanoplastics under defined conditions and validate that the photochemical degradation is consistent with plastics harvested from the Pacific Ocean. Machine learning algorithms trained with accelerated weathering data successfully classify weathered plastics from nature. We demonstrate that photodegradation of poly(ethylene terephthalate) (PET)-containing plastics produces enough CO 2 to induce a mineralization process that results in the deposition of CaCO 3 on nanoplastics. Finally, we determine that despite UV-radiation induced photochemical degradation and mineral deposition, nanoplastics retain their ability to sorb, mobilize, and increase bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in water and under simulated physiological gastric and intestinal conditions.

Nanoplastics alter ecosystem multifunctionality and may increase global warming potential

“…The increasing plastic pollution is undoubtedly becoming a global problem (Borrelle et al, 2020; Stegmann et al, 2022). Owing to the poor management of plastic waste, the large plastic debris can be fragmented into microplastics (0.1 μm–5 mm) and nanoplastics (<0.1 μm) under the actions of mechanical abrasion, thermal/photo‐degradation, and biological degradation (Schiferle et al, 2023; Wang, Li, et al, 2023). Therefore, it is not surprising that microplastics (MPs) and nanoplastics (NPs) are detected in both urban and remote locations (Allen et al, 2022; Machado et al, 2018).…”

In Vitro Toxicity and Modeling Reveal Nanoplastic Effects on Marine Bivalves

“…3,4 As larger plastic pieces break down through mechanical, thermal, and biological degradation, they transform into microplastics (MPs, 1 μm−5 mm) and even smaller nanoplastics (NPs, < 1000 nm). 5,6 These particles pervade aquatic ecosystems, presenting a significant and omnipresent threat to these environments. 7,8 The issue of NP contamination and its ecotoxicological effects have garnered increasing attention from both the public and the scientific community.…”

“…A dramatic surge in plastic production has resulted in the generation of 8.7 billion tonnes of plastic waste from 1950 to 2021. , This unchecked growth, combined with subpar waste management practices, projects an alarming future where, by 2050, our environment could be burdened with approximately 12 billion tonnes of plastic waste. , As larger plastic pieces break down through mechanical, thermal, and biological degradation, they transform into microplastics (MPs, 1 μm–5 mm) and even smaller nanoplastics (NPs, < 1000 nm). , These particles pervade aquatic ecosystems, presenting a significant and omnipresent threat to these environments. , The issue of NP contamination and its ecotoxicological effects have garnered increasing attention from both the public and the scientific community.…”