Nanotechnology is one of the most promising technologies of the twenty-first century. These applications are increasing exponentially because of the extremely small size of a large surface area per unit of volume. There is a great diversification in shape and function of manufactured nanoparticles; such as the large variety of polymers, dendrimers, fullerenes, carbon nanotubes, nanoribbons. Regardless of the numerous benefits that are obtained from the use of nanoparticles, one cannot be oblivious to the potential dangers associated with their exposure. Nanoparticles are present in our environment and surroundings from natural sources as well as from anthropogenic sources. Because of the extremely small size they can easily invade the human body through inhalation, ingestion, skin penetration, injections and via medical devices. Due to higher stability, they are foreseen to remain in the body and the environment for the longer periods of time. But unfortunately, limited information is available on their potential adverse effects on the health. [ABSTRACT FROM AUTHOR]