Polystyrene Nanoplastic Behavior and Toxicity on Crustacean Daphnia magna: Media Composition, Size, and Surface Charge Effects

Abstract

Concerns about the possible ecotoxicological implications of nano-sized plastic materials in the freshwater environment are growing with the increasing use of plastic materials. The present study focuses on the behavior and effects of amidine-functionalized polystyrene (NPLs) of 20, 40, 60, and 100-nm-size in freshwaters and different synthetic media. Daphnia magna was exposed to increasing concentrations from 0.5 to 30 mg/L (and from 0.5 to 100 mg/L for 100-nm-sized NPLs). The results revealed no significant aggregation in ultra-pure water, culture media, and synthetic water. In the presence of natural organic matter, NPLs of 20 and 40 nm displayed better stability in both freshwater and synthetic media, whereas a significant aggregation of 60 and 100 nm PS NPLs was found. All the studied PS NPLs with size between 20 and 100 nm exhibited acute toxicity to D. magna. The observed 48-h immobilization strongly depended on the primary size of PS NPLs, with 20 and 40-nm-size PS NPLs inducing a stronger effect in both freshwaters and synthetic media. Water quality variables such as pH, cation and anion composition, and DOC were of secondary importance. The results of the present study confirmed the toxicity of NPLs of different sizes to crustaceans in natural freshwater and synthetic media and demonstrated the importance of the primary size of NPLs in the behavior and effects of NPLs.

Protein binding on acutely toxic and non-toxic polystyrene nanoparticles during filtration by Daphnia magna

“…28 More recently the importance of the surface charge on PS nanoparticles 29 and the size of PS-NH 2 (ref. 30) has been studied in detail. The weathering of PS nanoparticles and the eco-corona formation have been seen to influence nanoparticle, suggesting that biomolecules on the surface are important for the toxicity.…”

Polystyrene nanoplastics differentially influence the outcome of infection by two microparasites of the host Daphnia magna

“…D. magna typically shows a higher resistance to contaminants than smaller Daphnia species [80], including to polystyrene NPs [81], which may indicate that higher concentrations of polystyrene NPs are also required to trigger the beneficial responses attributed to hormesis, as compared with D. longispina complex. In a recent study by Pochelon et al [82], polystyrene NPs with a size of 100 nm (the same that was used in the present experiment) led to the slowest doseresponse curve for immobilization of D. magna, as compared with smaller size categories of the same particles. Moreover, the maximum concentration tested in that study was 30 mg l −1 , suggesting that further negative effects could be reached at higher concentrations of polystyrene NPs.…”

“…In a recent study by Pochelon et al . [ 82 ], polystyrene NPs with a size of 100 nm (the same that was used in the present experiment) led to the slowest dose–response curve for immobilization of D. magna , as compared with smaller size categories of the same particles. Moreover, the maximum concentration tested in that study was 30 mg l −1 , suggesting that further negative effects could be reached at higher concentrations of polystyrene NPs.…”

Defining Quality Criteria for Nanoplastic Hazard Evaluation: The Case of Polystyrene Nanoplastics and Aquatic Invertebrate Daphnia spp.

“…In total, 38 scientific papers were retrieved for this analysis [ 6 , 9 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. As different experimental set-ups (e.g., different particle sizes, toxicity endpoints) were applied in the studies, each of these was considered an ecotoxicity data point.…”