Abstract
Titanium dioxide nanoparticles (TiO2 NPs) are the most produced nanomaterial for food additives, pigments, photocatalysis, and personal care products. These nanomaterials are at the forefront of rapidly developing indispensable nanotechnology. In all these nanomaterials, titanium dioxide (TiO2) is the most common nanomaterial which is being synthesized for many years. These nanoparticles of TiO2 are widely used at the commercial level, especially in cosmetic industries. High usage in such a way has increased the toxicological consequences of the human population. Several studies have shown that TiO2 NPs accumulated after oral exposure or inhalation in the alimentary canal, lungs, heart, liver, spleen, cardiac muscle, and kidneys. Additionally, in mice and rats, they disturb glucose and lipid homeostasis. Moreover, TiO2 nanoparticles primarily cause adverse reactions by inducing oxidative stress that leads to cell damage, inflammation, genotoxicity, and adverse immune responses. The form and level of destruction are strongly based on the physical and chemical properties of TiO2 nanoparticles, which administer their reactivity and bioavailability. Studies give indications that TiO2 NPs cause both DNA strand breaks and chromosomal damages. The effects of genotoxicity do not depend only on particle surface changes, size, and exposure route, but also relies on the duration of exposure. Most of these effects may be because of a very high dose of TiO2 NPs. Despite increased production and use, epidemiological data for TiO2 NPs is still missing. This review discusses previous research regarding the impact of TiO2 NP toxicity on human health and highlights areas that require further understanding in concern of jeopardy to the human population. This review is important to point out areas where extensive research is needed; thus, their possible impact on individual health should be investigated in more details.