Formulation Controls the Potential Neuromuscular Toxicity of Polyethylene Photoproducts in Developing Zebrafish

Abstract

Sunlight transforms plastic into water-soluble products, the potential toxicity of which remains unresolved, particularly for vertebrate animals. We evaluated acute toxicity and gene expression in developing zebrafish larvae after 5 days of exposure to photoproduced (P) and dark (D) leachates from additive-free polyethylene (PE) film and consumer-grade, additive-containing, conventional, and recycled PE bags. Using a "worst-case" scenario, with plastic concentrations exceeding those found in natural waters, we observed no acute toxicity. However, at the molecular level, RNA sequencing revealed differences in the number of differentially expressed genes (DEGs) for each leachate treatment: thousands of genes (5442 P, 577 D) for the additive-free film, tens of genes for the additive-containing conventional bag (14 P, 7 D), and none for the additive-containing recycled bag. Gene ontology enrichment analyses suggested that the additivefree PE leachates disrupted neuromuscular processes via biophysical signaling; this was most pronounced for the photoproduced leachates. We suggest that the fewer DEGs elicited by the leachates from conventional PE bags (and none from recycled bags) could be due to differences in photoproduced leachate composition caused by titanium dioxide-catalyzed reactions not present in the additive-free PE. This work demonstrates that the potential toxicity of plastic photoproducts can be product formulation-specific.

Minimizing the Environmental Impacts of Plastic Pollution through Ecodesign of Products with Low Environmental Persistence

“…This poses challenges in knowing whether k d represents the chemical degradation (depolymerization) of the polymer or merely the physical degradation (disintegration) to microplastics. Future research should prioritize the relative importance and controls of plastic degradation processes and products, as well as the environmental impacts (e.g., ecotoxicity) of any degradation products and leachable compounds released from plastics into the environment. , …”

“…Future research should prioritize the relative importance and controls of plastic degradation processes and products, as well as the environmental impacts (e.g., ecotoxicity) of any degradation products and leachable compounds released from plastics into the environment. 76 , 77 …”

Identification of Additives in Disposable Face Masks and Evaluation of Their Toxicity Using Marine Medaka (Oryzias melastigma)

“…The additives in the face masks can be leached out once they are in the ocean, posing a potential hazard to marine organisms. , Previous studies have demonstrated that plastic additives can cause various adverse effects on the development, nerve, and endocrine system in aquatic animals. − In addition, mask fragments can downregulate the transcription of target genes related to reproduction in zebrafish, cause histopathological alterations of the liver, gills, and intestine of zebrafish, and disrupt their aggressive behavior . However, research on the toxicity of face masks, particularly their additives, to marine organisms is extremely scarce.…”