%0 Journal Article
%T An Approach to Tentative Reference Levels Setting for Nanoparticles in the Workroom Air Based on Comparing Their Toxicity with That of Their Micrometric Counterparts: A Case Study of Iron Oxide Fe3O4
%A Boris A. Katsnelson
%A Larisa I. Privalova
%A Sergey V. Kuzmin
%A Vladimir B. Gurvich
%A Marina P. Sutunkova
%A Ekaterina P. Kireyeva
%A Ilzira A. Minigalieva
%J ISRN Nanotechnology
%D 2012
%R 10.5402/2012/143613
%X We overview the state of the art in the field of safe exposure levels setting for nanomaterials together with the previously published results of our experimental investigations characterizing comparative toxicity of the iron oxide F e 3 O 4 (magnetite) in the form of microparticles and nanoparticles of different size and comparative activity of the defensive alveolar phagocytosis response to their pulmonary deposition. An approach to the substantiation of acceptable workplace exposure limits of metallic nanoparticles is discussed and, specifically, the tentative reference level for magnetite nanoparticles is recommended. 1. Introduction The development of nanotechnologies has led to the emergence of a lot of materials containing nanoscale particles. By convention, a particle is defined as being in the nano-scale range if it has at least one linear dimension not exceeding 100£¿nm. Nanoparticles (NPs) of various materials find wide application in different industries, in medicine, and in science. In particular, magnetite (Fe3O4) NPs are increasingly often used in medicine and biology as selective carriers of drugs to organs, as markers controlled by an external magnetic field, as cancer cell killers (thanks to local hyperthermia caused by the heating of these NPs in a external variable magnetic field), as a contrast material in magnetic resonance tomography, and so forth. Looking for advance in general nanotoxicology, uncoated engineered NPs of any iron oxide present an interesting research object because such research brings us nearer to the answer of the important question of whether or not a material which is extremely low toxic both in bulk and in the micrometer particle size range may become so toxic in the nanostate, that it may present a serious hazard to human health in the course of its production and use. A good evidence of the rather low toxicity of usual (not nano-scale) iron oxides is that they are allowed by the Joint Expert Committee on Food Additives (JECFA) for use as colouring agents due to their being practically innocuous at a systematic daily intake of up to 0.5£¿mg/kg. Theoretical grounds for expecting a sharp increase in the toxicity of a substance in the form of NPs have been highlighted by many authors (e.g., [1¨C4]), and it is not among the objectives of this paper to discuss these grounds. It should be noted, however, that analysis of a great number of published data obtained in actual research supports the statement that ¡°this common perception of greater nanoparticle toxicity is based on a limited number of studies¡± [5].
%U http://www.hindawi.com/journals/isrn.nanotechnology/2012/143613/