title: Joint toxicity prediction of nanoparticles and ionic counterparts: Simulating toxicity under a fate scenario.
abstract: The joint effects of NPs with other chemicals is not fully yet understood along with the joint effects of the particulate and dissolved forms/fractions. The predictability of joint effects is of great importance for environmental risk assessment. Therefore this study aimed at inferring on the predictability of NPs binary mixture toxicity based on their ionic counterparts' mixtures, and evaluating if the joint toxicity of two forms of the same element (NP and ion) acts as dilution of each other. Effects of individual and mixtures of ZnO and Ag NPs and their respective salts (AgNO3and ZnCl2) were studied in immobilization and feeding tests using Daphnia magna. NPs mixture toxicity patterns did not mirror their ionic counterparts' mixture toxicity responses and therefore their prediction should not rely on the available knowledge for regular chemicals. Regarding mixtures from the same element with different forms (NP and ions), both Zn and Ag mixtures showed a deviation from additivity, relying on the interaction between NP and ions. A synergistic effect was depicted when the concentrations of Ag ions increased, while antagonism was observed with AgNP increase in suspension. This is an expected pattern in long term studies due to dissolution, relating fate and toxicity.
authors: Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors: Sílvia
authors: S
authors: Lopes
authors: Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors: Carlos
authors: C
authors: Pinheiro
authors: Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal.
authors: Amadeu M V M
authors: AMVM
authors: Soares
authors: Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: sloureiro@ua.pt.
authors: Susana
authors: S
authors: Loureiro
mesh_terms: D000818:Animals; D002712:Chlorides / Q000633:toxicity*; D003198:Computer Simulation; D003621:Daphnia; D004347:Drug Interactions; D008954:Models, Biological; D053758:Nanoparticles / Q000633:toxicity*; D012834:Silver / Q000633:toxicity*; D012835:Silver Nitrate / Q000633:toxicity*; D023382:Toxicity Tests, Acute; D017967:Zinc Compounds / Q000633:toxicity*; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D002712:Chlorides; D017967:Zinc Compounds; D012834:Silver; C016837:zinc chloride; D012835:Silver Nitrate; D015034:Zinc Oxide
keywords: Additivity; Daphnia magna; Silver nanoparticles; Synergism and antagonism; Zinc oxide nanoparticles