Chronic toxic effects of fragmented polyvinyl chloride on the water flea Moina macrocopa

Abstract

Background: Although many studies have reported the detrimental potential of commercially synthesized sphere types of microplastics (MPs) and nanoplastics (NPs) on aquatic ecosystems, limited information is available on fragmented MPs and their chronic effects. Objective: This study aimed to evaluate potentially harmful effects of fragmented polyvinyl chloride (PVC; < 20 μm) in a range from 0.001 to 500 μg L−1 on a water flea model, Moina macrocopa. Physiological and biochemical effects of fragmented PVC were studied by analyzing the mortality, growth, and reproduction parameters, with evidence retrieved from biochemical components for 14 days. Results: Waterborne exposure to PVC fragments resulted in temporal bioconcentration through ingestion. The PVC fragments were egested in feces. The mortality was drastically increased by relatively higher concentrations (> 10 μg L−1) of fragmented PVC compared to that of the control group. Two concentrations of PVC fragments (100 and 500 μg L−1) significantly induced growth retardation, with expansion of intermolt periods and decreased the first day of reproduction and the number of neonates per brood. Exposure to PVC fragments induced fluctuations in oxidative status and antioxidant components, with inhibition in acetylcholinesterase activity. Conclusion: These results imply that fragmentation of MPs can induce a significant physiological and biochemical effects to aquatic crustaceans by inducing strong oxidative stress and impairing antioxidant defense.