We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Plastic composition drives the toxicity of UV-aged melamine–polypropylene microplastics, nanoplastics, and leachates on Raphidocelis subcapitata
Original title: Plastic composition drives the toxicity of UV-aged melamine–polypropylene microplastics, nanoplastics, and leachates on Raphidocelis subcapitata
AI summary Read the abstract
When sunlight breaks down plastic, the smallest particles and dissolved chemical fragments turn out to be the most toxic to algae, but surprisingly, plastics with chemical stabilizers (added to make plastic more durable) weren't always safer—sometimes they released extra harmful byproducts as they broke down. This suggests that what's mixed into plastic during manufacturing can matter as much as the plastic itself when it comes to environmental and potentially human health effects, since these algae sit at the base of the food chain we depend on.
This study investigates how the plastic additive composition influences the toxicity of UV-aged polypropylene (PP) microplastics (MPs), nanoplastics (NPs) and leachates toward the green alga Raphidocelis subcapitata. Three materials were compared: an antioxidant-deprived additive-free PP (PPd), a base-stabilized PP containing Irgafos 168 (PPc), and a compounded melamine-polypropylene with Irgafos 168 (PPf). UV-irradiation induced surface oxidation and fragmentation across all samples, releasing NPs (< 1 µm) and ultrafiltrates (< 50 kDa), representing the dissolved and colloidal fraction. Characterization by ATR-FTIR, SEM, and GC/MS confirmed that the material deprived of the antioxidant (PPd) underwent more intense oxidation, displaying a higher abundance of oxygenated functional groups and smaller particle sizes compared to stabilized forms. Toxicity assays with R. subcapitata demonstrated a clear size-dependent trend, with ultrafiltrates > NPs > small MPs (1-50 µm) > large MPs (50-500 µm), yet the magnitude of this toxicity was strongly driven by the additive composition. Growth inhibition, reactive oxygen species (ROS) generation, and membrane depolarization were significantly increased in the absence of antioxidant additives across all size fractions, indicating higher bioavailability and reactivity of UV-generated particle surfaces or leached low-molecular-weight oligomers. But still, stabilized melamine-PP released additional leaching products and its ultrafiltrates enriched in oxidized additives and low-molecular-weight oligomers, caused high cytotoxic and oxidative responses. Overall, these results demonstrate that the additive composition not only modulates polymer stability during UV ageing but also governed the toxicity of plastics particles and leaching products toward aquatic primary producers, underscoring the ecological relevance of plastic ageing processes in aquatic ecosystems.
More Papers Like This
Toxic plastisphere: How the characteristics of plastic particles can affect colonization of harmful microalgae and adsorption of phycotoxins
AI summary Read the abstract
Researchers found that microplastic particles in water can serve as surfaces for harmful algae to grow on and for algae-produced toxins to stick to. Smaller and sun-aged microplastic particles absorbed more toxins than larger or newer ones, meaning the most common microplastics in the environment may carry the greatest risk. This matters for human health because contaminated microplastics could transfer harmful algal toxins into seafood and drinking water.
Ecotoxicity of micro- and nanoplastics on aquatic algae: Facts, challenges, and future opportunities
AI summary Read the abstract
This review provides a comprehensive assessment of how micro- and nanoplastics harm aquatic algae, which form the base of ocean and freshwater food chains. The toxic effects include reduced growth, oxidative stress, and disrupted photosynthesis, with nanoplastics generally causing more damage than larger particles. Since algae support the entire aquatic food web, their decline from plastic pollution could reduce the quality and safety of fish and shellfish consumed by people.
Photochemical Aging Triggers Zn(II) Mobilization and Toxicity in Metallopolymer Microplastics to the Green Macroalga Ulva
AI summary Read the abstract
Sunlight exposure makes zinc-containing microplastics break down and leak harmful chemicals, and this study found that the "aged" plastic was more toxic to marine algae than fresh plastic — even more toxic than the zinc alone, meaning other released chemicals are adding to the harm. This matters because microplastics don't just sit unchanged in the ocean; sunlight actively transforms them into something more dangerous over time, which could affect marine food chains that humans depend on.
Aquatic toxicity of UV-irradiated commercial polypropylene plastic particles and associated chemicals
AI summary Read the abstract
Researchers tested the aquatic toxicity of UV-degraded polypropylene plastic particles on water fleas and algae. They found that smaller nanoplastic particles were significantly more toxic than larger microplastics, and the presence of a common plastic additive (the antioxidant Irgafos 168) made the particles even more harmful. The study suggests that as plastics break down in the environment and release their chemical additives, they may become increasingly dangerous to aquatic life.
Microplastics leachate may play a more important role than microplastics in inhibiting microalga Chlorella vulgaris growth at cellular and molecular levels
AI summary Read the abstract
Researchers found that chemical compounds leaching from aged microplastics may be more harmful to algae than the microplastic particles themselves. UV-weathered polyethylene and PVC released substances that inhibited algae growth, caused oxidative stress, and altered gene expression more severely than direct particle exposure. The study suggests that the chemicals released by degrading microplastics deserve more attention as a source of aquatic toxicity.
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.