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Silver is a natural metal and is geologically rare. It has been used in making jewellery, electronic equipment and photographic processes amongst other products. People are exposed to very low amount of silver daily, an amount that is not threatening their health. However, silver is persistent and bioaccumulate in the environment, which makes it an environmental hazard. Although silver is mostly found under its ionic form, silver nano particles are becoming more and more part of the anthropogenic inputs. There are many unknown aspects of silver nano particles, which makes them hard to monitor and regulate. This study provides a start point in the understanding of the silver nanoparticles behaviour and toxicity. The results consisted of two main parts : biological and chemical aspects. Nevertheless, the knowledge about silver nano particles at the moment is scarce, and this study may set a start point in this research field.

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