engleski

Adverse impact of copper nanoparticles, and the role of copper speciation, in embryogenesis of sea urchin Sphaerechinus granularis

Harbours have long been known as pollution hotspots due to a range of anthropogenic inputs such as, for example, tributyltin which was historically used in ship paints to prevent biofouling but also resulted in toxicity to non- target organisms. Recently the use of copper, as copper nanoparticles (CuNP), in anti-fouling formulations has been gaining popularity. However, there is relatively little data available on the behaviour of such particles in marine waters and how they impact on biota. We report herein on the behaviour and fate of CuNP in marine waters and their impact on embryogenesis of sea urchin Sphaerechinus granularis. The colloidal stability of CuNP in seawater (S∙38), and hence potential residence time in the water column, was investigated as a function of various types of natural organic matter (NOM). NOM discouraged CuNP aggregation over a wide concentration range, e.g. humic acid (0.1-10 mg/L) and alginate (1-10 mg/L). Further, NOM decreased Cu+ ion release from nanoparticles, with Cu+ concentrations increasing 36% for uncoated nanoparticles compared to 18% in the presence of NOM. Exposure of S. granularis zygotes to CuNP nanoparticles showed distinctly different outcomes after 72 h. Larval malformations and delayed development increased with increasing concentrations, with CuO showing the lowest EC50 (concentration inducing 50% abnormal development) at 51.47±14.74 μg/L, while Cu2O and Cu0 were less toxic with EC50 values of 106.73±26.28 and 193.86±45.39 μg/L, respectively. These results contribute to a better understanding of the persistence of CuNP in harbour waters and how subsequent copper speciation may modulate toxicity to biota.

port ; biofouling ; dissolution kinetics ; Cu+ ion ; developmental defect

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