Assessing potential hazard of zinc oxide nanoparticles to human health

Wide implementation of nanomaterials in various economic activities and associated contamination of environmental objects create health risks for workers and general population. Nanoparticles have physiochemical properties that are different from their micro-sized analogues, which may cause more pronounced negative effects upon intake. In this regard, assessment of safety of nanoindustry products is an urgent hygienic problem and the basis for developing recommendations aimed at minimizing health risks. The aim of the study was to assess potential hazards of a nanomaterial for human health using zinc oxide nanoparticles (ZnO NPs) as an example. Potential hazard of ZnO NPs was assessed using a set of indicators based on implementation of the predictive-analytical procedure in accordance with MR 1.2.2522-09. The analysis of ZnO NPs properties indicates that they belong to nano-sized particles (from 6 to 100 nanometers). During cell membrane penetration, ZnO NPs were shown to stimulate greater production of free radicals that cause damage to supramolecular structures. They transform proteomic profile and metabolic reactions changing the expression of proteins that regulate the integrity of cytoskeleton, nuclear matrix and apoptotic process, which leads to cell death. Cellular and molecular changes are manifested through morphofunctional tissue impairments in tissues organs where ZnO NPs bioaccumulate (the liver, kidneys and lungs). Negative effects are manifested as redox imbalance, cytolysis, impaired filtration processes, weaker cellular immunity and, as a consequence, developing inflammatory, dystrophic and necrotic processes. Implementation of the predictive-analytical procedure showed that ZnO NPs are potentially highly hazardous for human health (according to the hazard coefficient D = 2.102). High potential hazard for human health indicates that it is necessary to investigate remote and specific effects of ZnO NPs in order to perform complete hygienic assessment of their safe levels. This will allow achieving more effective development of preventive measures aimed at minimizing health risks caused by ZnO NPs for workers and general population.