title: Chronic toxicity of ZnO nanoparticles, non-nano ZnO and ZnCl2 to Folsomia candida (Collembola) in relation to bioavailability in soil.
abstract: The chronic toxicity of zinc oxide nanoparticles (ZnO-NP) to Folsomia candida was determined in natural soil. To unravel the contribution of particle size and free zinc to NP toxicity, non-nano ZnO and ZnCl(2) were also tested. Zinc concentrations in pore water increased with increasing soil concentrations, with Freundlich sorption constants K(f) of 61.7, 106 and 96.4 l/kg (n = 1.50, 1.34 and 0.42) for ZnO-NP, non-nano ZnO and ZnCl(2) respectively. Survival of F. candida was not affected by ZnO-NP and non-nano ZnO at concentrations up to 6400 mg Zn/kg d.w. Reproduction was dose-dependently reduced with 28-d EC50s of 1964, 1591 and 298 mg Zn/kg d.w. for ZnO-NP, non-nano ZnO and ZnCl(2), respectively. The difference in EC50s based on measured pore water concentrations was small (7.94-16.8 mg Zn/l). We conclude that zinc ions released from NP determine the observed toxic effects rather than ZnO particle size.
authors: Department of Animal Ecology, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands. pauline.kool@falw.vu.nl
authors: Pauline L
authors: PL
authors: Kool
authors: Maria Diez
authors: MD
authors: Ortiz
authors: Cornelis A M
authors: CA
authors: van Gestel
mesh_terms: D000818:Animals; D001181:Arthropods / Q000187:drug effects*; D002712:Chlorides / Q000032:analysis / Q000633:toxicity*; D053768:Metal Nanoparticles / Q000032:analysis / Q000633:toxicity*; D010316:Particle Size; D012098:Reproduction / Q000187:drug effects; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*; D036401:Toxicity Tests, Chronic; D017967:Zinc Compounds / Q000032:analysis / Q000633:toxicity*; D015034:Zinc Oxide / Q000032:analysis / Q000633:toxicity*
chemical_list: D002712:Chlorides; D012987:Soil; D012989:Soil Pollutants; D017967:Zinc Compounds; C016837:zinc chloride; D015034:Zinc Oxide