As described before in the first Frontier Report of this series, there are two types of nanoparticles to be considered in hygiene science; One is the environmental nanoparticle emitted from automobiles and the other is the manufactured nanoparticle. In general nanoparticles (less than 100 nm) are reported to be permeable through cell membrane and tissues and their large surface area is responsible for the greater toxicity compared to larger particles. However, there are contradictory reports on the health effects of nanoparticles. Recent reports suggest that carbon nanotubes, fiber-shaped biopersistent nanoparticles, resemble asbestos in the pathogenesis of granuloma and mesothelioma. As such we summarize health effects of environmental and manufactured nanoparticles in the literature so far including our studies, in this report.