Abstract: Living is made comfortable by continues and the enormous advancement of Science and Technology so far. Nano technology is now days a favorite tool for technologists from academia as well as industrial sector. Nano particles were present in earlier days also, but up to limited extent. The prevailing use of Nano particles now days, to serve almost every sector of human life, would result in to increased concentration of Nano particles in the environment; eventually to term them as a pollutant. Metal absorption in human body is a very complicated phenomenon itself. For trace element absorption a protein, namely, metallothionein is responsible. Metal particles, when enter the human body, are likely to accumulate in kidney, lungs or brain. Greater surface to volume ratio of Nano particles makes them highly reactive and may act as catalyst even. This gives a call to understand the biochemistry behind metal absorption in human body and to define a strategy for the use and production of nano particles for their discrete use.