Effects of microplastics on aquatic life, invertebrate plastic degradation, plant growth, and human cells

Microplastic pollution is an urgent environmental issue with widespread impacts on biological systems. This study examines the effects of microplastics on seed germination and early growth of barley (Hordeum vulgare L.) and perennial ryegrass (Lolium perenne L.), the biodegradation of polystyrene by mealworms (Tenebrio molitor Linnaeus, 1758), and the cytotoxicity of mealworm-derived excreta on human cells. Barley and ryegrass seeds were exposed to microplastics of varying sizes, surface charges, and concentrations to assess their impact on germination and growth patterns. Water fleas (Daphnia spp.) were exposed to microplastics to evaluate their survival under varying conditions. Additionally, mealworms were fed polystyrene to evaluate their ability to degrade plastics to obtain the excreta possibly containing digested plastics. The cytotoxicity of mealworm excreta was assessed on human Caco-2 cells using WST-8 viability assays. This integrated approach provides new insights into the ecological and cellular effects of microplastic pollution and highlights the potential of mealworm biodegradation as a plastic waste management strategy.