Nanotoxicology and Its Implications in the Human Health

Hundreds of nanoparticles (NPs)-containing products are already in commercial production, but toxicological evidences are emerging to fear that such nanosized materials could have undesirable human health and environmental effects. In this context, nanotoxicology research plays a key role in ensuring a scientific basis to the risk assessment of NP. Effects of NPs in biological systems are documented including cytotoxicity, genotoxicity, cardiotoxicity, the crossing of blood-brainbarrier, the induction of oxidative stress and the interaction of immune system components. However, at present, a huge health and safety questions remain unsolved, leading the scientific community to severe controversy. This is particularly due to: (i) the paucity of data concerning the factors that affect uptake, translocation to other tissues, intracellular trafficking in relation to the toxicity of NPs; and the role of fundamental physical factors that largely determine the functional and toxicological impact of NPs, such as shape, surface area, crystal structure, porosity and modification characteristics (surface charge, hydrophilicity, biological and chemical coatings with attached ligands or surfactants); (ii) experimental conditions far from reality, such as: unrealistic high doses of NPs in exposing in vivo and in vitro test systems; absence of a minimum-characterisation; lack of a minimum-information on metrological details. Consequently, we can compare studies at only with great difficulty; we are not able to interpret the biological effects with the necessary severity. In summary, more gaps and uncertainties than certainties exist about the conclusions of the nanotoxicological studies already carried out so far and very few findings are conclusive about the nature and extent of the hazards of NPs. This may be sufficient to support precautionary action (“no data-no market”). Although nanotoxicology research is still in an infant phase further extension is an urgent needed for assessing the impact of nanomaterials relevant to workplace, general environment and consumer safety.