0
Article Tier 2 Sign in to save

Aging of microplastics affects their surface properties, thermal decomposition, additives leaching and interactions in simulated fluids

The Science of The Total Environment 2020 338 citations

AI summary Read the abstract

Researchers studied how environmental aging changes the properties of commercial microplastics and their behavior in simulated stomach and intestinal fluids. They found that aging caused surface cracking and fragmentation, reduced heat resistance, and increased the release of pigment chemicals into digestive fluids. These released pigments were shown to interact with digestive enzymes, suggesting that weathered microplastics may pose greater health risks than fresh ones when ingested.

Polymers
Body Systems

Most microplastics (MPs) have undergone extensive aging in the environment. Aged MPs exhibit different physical and chemical properties from unaged ones. Here, we studied the effects of accelerated aging on the characteristics and pyrolysis of commercial pigmented MPs, as well as pigments leaching and their interactions in simulated gastric and intestinal fluids of mammals. We report that the carbonyl index, surface area, and color change of MPs increased after aging treatment. Cracks and fragmentation of MPs facilitated the accessibility of light and oxygen to internal layer and therefore accelerated the aging process. TGA/GC-MS analysis showed that the high temperature resistance of MPs decreased after aging. Thermal decomposition of pigments and polyethylene occurred in temperature ranges of 340-406 °C and 406-550 °C, respectively. Mono (di)-alkenes and saturated alkanes were the thermal decomposition products of polyethylene. Aging of MPs also caused an increased release of pigments and prolonged aging time led to more release in simulated fluids. Pigments would result in fluorescence quenching of the enzymes through binding interactions once they were released from MPs into simulated fluids. Charge neutralization and polymer bridging accounted for the formation of pigment-enzyme complexes and flocs. These novel findings will allow us to better assess how aging process affects the characteristics, leaching, and toxicity of MPs.

More Papers Like This

Systematic Review Tier 1

Recent advances on microplastic aging: Identification, mechanism, influence factors, and additives release

AI summary Read the abstract

This review found that environmental aging transforms microplastic surface properties through abrasion, chemical oxidation, UV irradiation, and biodegradation, altering their environmental behavior and ecological risk. Aging also triggers the release of toxic plastic additives, but significant gaps remain between laboratory aging simulations and real-world conditions.

Article Tier 2

Contaminant release from aged microplastic

AI summary Read the abstract

Researchers exposed recycled plastic granules of polyethylene, PVC, and polystyrene to simulated aging conditions including UV radiation and high temperatures. They found that aging significantly increased the rate at which chemical additives leached from the plastic particles into water, with UV exposure having the greatest effect. The study highlights that weathered microplastics in the environment may release harmful chemicals at much higher rates than fresh plastic materials.

Article Tier 2

Effects of aging on environmental behavior of plastic additives: Migration, leaching, and ecotoxicity

AI summary Read the abstract

This review examines how the aging and weathering of microplastics in the environment causes chemical additives like plasticizers, flame retardants, and antioxidants to leach out. As microplastics age through UV exposure, heat, and biological activity, they release these additives more readily, increasing the toxic risk to organisms. The findings are important because they show that older, weathered microplastics found in the real world may be more chemically hazardous than fresh plastics used in most lab studies.

Article Tier 2

A comprehensive review of microplastic aging: Laboratory simulations, physicochemical properties, adsorption mechanisms, and environmental impacts

AI summary Read the abstract

This review examines how microplastics change as they age in the environment through exposure to sunlight, water, and chemicals, becoming rougher and more chemically reactive over time. Aged microplastics absorb more pollutants than fresh ones and release harmful additives and free radicals, meaning the microplastics people encounter in the real world may be more dangerous than the pristine particles typically used in lab studies.

Review Tier 2

Mechanism and characterization of microplastic aging process: A review

AI summary Read the abstract

This review explains how microplastics age and break down in the environment through sunlight, heat, and chemical reactions, and why this aging process matters. As microplastics weather, their surfaces change in ways that make them better at absorbing toxic pollutants and more harmful to living organisms. Understanding these aging processes is important because the microplastics people encounter in food and water have typically been weathered, meaning they may be more dangerous than the fresh plastics used in most lab studies.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper