Nanoparticles: Toxicity Assessment, Health Risks and Medical Applications

With decreasing size of atmospheric aerosol particles, their ability to penetrate deeper into the respiratory system increases. Ultrafine particles (UFPs) and nanoparticles (NPs), defined as atmospheric aerosol particles smaller than 100 nm, have been identified as potentially the most dangerous to human health due to their ability to penetrate easily the lung epithelial wall into the blood, which transports them to other organs. Despite considerable toxicological evidence of the potential harmful effects of these particles on human health, the appropriate metric for assessing their health effects is still unclear. This article describes various methods used to assess particle toxicity, the mechanism of toxic action of particles and the use of NPs in medicine.