Nanoparticles health risk assessement

Nanomaterials are a diverse class of small-scale (<100 nm) substances formed by molecular-level engineering to achieve unique mechanical, optical, electrical, and magnetic properties. Widespread application of nanomaterials confers enormous potential for human exposure and environmental release. It is necessary to standardize systematic terminology for materials composition and features, methods of analysis and to increase knowledge on  toxicity effects. The greatest current risk regards occupational health of workers, therapy and diagnostic applications , production of cosmetics, food packaging technology.  The variety of routes by which NPs could be taken up by the body complicates risk assessment. Gastrointestinal exposure is represented by food constituents, pharmaceuticals, water, cosmetics, dental prosthesis debris, cleared by mucociliary escalator, endogenous production. In dermal exposure we can have three main pathways of penetration: intercellular, transfollicular , transcellular. If NPs enter into the lung, it is possible an epithelial translocation from alveolar region or  deposition in interstitium or a passage through capillary endothelium. For sampling of NPs we should consider parameters such as: number concentration, surface area, mass concentrations, weighted size distribution, state of agglomeration, surface reactivity, chemical composition, morphology  In NPs hazard identification we have to consider if there are similar properties to other chemical forms, if there are different properties and no informations available. We can use in vitro studies to Know differences  between the forms and in vivo to investigate uptake and distribution.  Risk characterization  regards safety of workers, consumers and local populations, potential human re-exposure, their biopersistence, simultaneous exposure, additive effects, the presence of severe chronic respiratory disease the toxicity of smaller particles. The management should avoid, prevent, reduce, transfer, self-retain risks. It is possible only with an interdisciplinary approach, ending in risk communication, based on integrated program and publication data, using with caution all information available.