Toxicity of nanoparticles

Abstract This chapter will focus on the most relevant recent advances in our understanding of nanoparticle toxicity and their adverse health effects in humans. We will show compelling evidence related to nanoparticle uptake, biodistribution, and putative roles in human disease etiopathogenesis. Nanoparticles have different physicochemical properties compared with larger particles or bulk materials. As a result, they are increasingly being used in applications in various fields. It is of paramount importance to be aware of their toxicity for several reasons. Exposure to nanoparticles can occur when handling them, as a result of accidental environmental release, during waste disposal and or recycling. Nanoparticles are very small particles that can enter human body through several routes, such as inhalation, ingestion, or dermal exposure. Due to their small size, they can evade the immune system, enter circulatory apparatus, and reach organs. Being smaller than cells, nanoparticles can penetrate cell walls, enter organelles, and disturb cell physiology, leading to cytotoxicity and genotoxicity. A large amount of data including in vitro cell studies, in vivo studies in animals and humans, epidemiological studies, and occupational health studies report on nanoparticle toxicity. There is a growing body of evidence linking nanoparticle exposure to many adverse health effects such as cardiovascular diseases, arteriosclerosis, high blood pressure, blood clots, stroke, arrhythmia, heart disease, heart attack; respiratory diseases such as lung cancer; neurodegenerative diseases such as dementia, Alzheimer's and Parkinson's diseases; and reproductive system toxicity. As such, improving our overall understanding of the toxic effects of these novel materials will help us prevent undesirable health consequences.