10th U6+ Consortium of African Universities International Conference

The last decade has witnessed a continuous increase in the use of nanotechnology. Thousands of products varying from food, cosmetics, clothes, military equipment, and personal care products are now available with nanoparticle contents. Due to the numerous applications of nanoparticles in consumer products, the chances of human exposure through ingestion, inhalation, and dermal contact are significantly increased. There is a growing concern about the possible adverse health effects of nanoparticles on the environment and humans. Nanoparticles may aggregate and interact in the environment in water, solids, or sediments, leading to co-exposure either via the food chain or drinkable water, which could bio-accumulate and magnify in the ‘food chain cycle’, eventually leading to human exposures. Exposure of these nanoparticles to the biological system may elicit novel distribution, immune responses, absorption at physiological barriers, and interaction/impairment of DNA repair processes. In general, smaller particles are thought to interact more strongly with biological systems compared to larger particles. Nanoparticles have been shown to be mutagenic, carcinogenic, teratogenic, immunotoxic, hematotoxic, and cytotoxic in different biological systems and in vitro studies. Toxicological data have shown that nanoparticles are toxic to both somatic and germ cells. Also, it has been shown that co-exposure to nanoparticles is more toxic than individual nanoparticles. The ability of nanoparticles to damage the DNA has been suggested to be through systemic alterations. In vivo and in vitro genetic and reproductive toxicity studies of nanoparticles are very limited and the data so far reported is insufficient, hence, more experimental data are needed. Furthermore, despite the fact that humans can be exposed to a variety of nanoparticles at the same time, most studies have been limited to the toxicity of individual nanoparticles. There must be caution in the use of nanoparticles to prevent potential public health crisis.