We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Formation of Environmentally Persistent Free Radicals on Microplastics under Light Irradiation
AI summary Read the abstract
Four types of virgin microplastics were aged under simulated solar irradiation and analyzed by electron paramagnetic resonance spectroscopy, finding that polystyrene and phenol-formaldehyde resin produced environmentally persistent free radicals (EPFRs) that decayed slowly, while polyethylene and PVC did not. The study identifies photoaged plastic surfaces as a previously unrecognized source of EPFRs—emerging contaminants with known health risks.
Microplastics (MPs) are presumed to be inert during aging under ambient conditions. In this study, four types of virgin MPs, including polystyrene (PS), phenol-formaldehyde resin (PF), polyethylene (PE), and polyvinyl chloride (PVC), were aged under simulated solar light irradiation. Surprisingly, several environmentally persistent free radicals (EPFRs), which are considered to be a type of emerging contaminant, were detected on the irradiated PS and PF, rather than PE and PVC, by electron paramagnetic resonance (EPR) spectroscopy. Depending on the photoaging duration time, the characteristic g-factors of the EPFRs produced on PS and PF were 2.0044-2.0049 and 2.0043-2.0044, respectively. The generated EPFRs on PS and PF decayed rapidly at the initial stage and then slowly disappeared with the elapsed aging time. Analyses by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) suggested that MPs might experience chemical chain scission, O2/H2O addition, and EPFR formation under the light irradiation. Accompanying with the formation of EPFRs, reactive oxygen species, such as O2•- and •OH, were also observed. The findings provide a novel insight to evaluate the potential hazards of MPs to organisms and ecosystems.
More Papers Like This
A Critical Review of an Environmental Risk Substance Induced by Aging Microplastics: Insights into Environmentally Persistent Free Radicals
AI summary Read the abstract
This review examines how microplastics generate long-lasting free radicals as they age in the environment through exposure to sunlight and chemical reactions. These environmentally persistent free radicals (EPFRs) on aged microplastics can cause oxidative stress and damage to living cells, adding a previously underappreciated layer of toxicity beyond the physical harm caused by the plastic particles themselves.
Formation of environmentally persistent free radicals on microplastics under UV irradiations
AI summary Read the abstract
This study found that UV light from the sun creates long-lasting free radicals on the surface of microplastics, with stronger UV producing more radicals faster. These environmentally persistent free radicals are chemically reactive and can damage cells and DNA. The finding is important because it means sunlight-weathered microplastics in the environment may be more harmful than fresh plastics, carrying these damaging free radicals into the body when ingested or inhaled.
Formation of environmentally persistent free radicals (EPFRs) and electron transfer in conjugated polymers and alkane polymers during aging
AI summary Read the abstract
Researchers used conductive atomic force microscopy to observe in real-time how environmentally persistent free radicals (EPFRs) form on aging microplastic surfaces, finding that UV exposure induces electron transitions that generate mobile, reactive electrons on both aromatic and alkane-chain polymers. These EPFRs can then produce reactive oxygen species that amplify ecological harm.
Elucidating the role of overlooked environmentally persistent free radicals and reactive chlorine species on photoaged chlorine-containing microplastics: New insights into formation mechanisms and health risks
AI summary Read the abstract
Researchers investigated the formation of environmentally persistent free radicals and reactive chlorine species on photoaged chlorine-containing microplastics like PVC and PVDC. The study revealed previously overlooked chemical transformations during microplastic aging that may pose additional health risks beyond the physical presence of the plastic particles themselves.
Aging Process of Microplastics in the Aquatic Environments: Aging Pathway, Characteristic Change, Compound Effect, and Environmentally Persistent Free Radicals Formation
AI summary Read the abstract
This review summarizes how microplastics age and transform in aquatic environments through oxidation, weathering, and fragmentation. Researchers documented changes in particle size, crystallinity, and surface chemistry during the aging process, and found that aged microplastics may interact synergistically with other environmental pollutants. The study also describes how photoaging generates environmentally persistent free radicals that could pose additional toxicity concerns.
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.