The science that deals with the study of materials or any particle so small and measured at the nanoscale is called “nanoscience”. The study of very small particles and their chemical and physical modifications at the nanoscale is not an easy task. Nanotechnology studies all of these small particles and manipulates them to advance new devices and materials. The name “nanotechnology” was coined in 1974 (). But the concept of manipulating nanoparticles has existed for centuries, mainly in manufacturing examples: Lycurgus cup from the 4th century, Damascus saber blades from the 13th and 18th centuries, etc. The introduction of nanotechnology was expected to bring multiple benefits to society in many areas such as energy production and conservation, pollution control and medicine (). The danger posed by this beneficial science must be understood before their use becomes widespread. Environmental scientists concerned about organismal health and environmental risks research and access the toxicity, distribution, and fate of nanoparticles released into the environment. The properties of nanoparticles can have a negative impact on the environment. The surface effects of nanoparticles are both favorable and unfavorable. When exposed to tissues or cells of the body, they are adsorbed to their surface. They are therefore widely used in the medical field for the administration of drugs (). By crossing the cell membrane or entering the bloodstream, nanoparticles can target other organs. Another important property is high solubility which is advantageous and reduces its toxicity, but some nanoparticles do not dissolve as easily or degrade, which can lead to accumulation in the body or in the environment (... .... middle of paper ....the system and chemical impacts on the ecosystem.() In the aquatic ecosystem, along with silver nanoparticles, nanocopper also damages the cell membrane and DNA at cellular level Also affects the fertility, physiology and survival of many aquatic organisms, including crustaceans, mussels and many fish species ()Nanoparticles cause damage after chronic exposure.(8) when AgNP. is present in salt water, the toxicity is reduced compared to fresh water The high ionic strength of the Ag+ ion creates a bond between the ion and the anion This will reduce the interaction of Ag+ at the level. gills where the cause of toxicity begins. In fresh water, due to reduction of anions, the Ag+ ion competes with other cations for gill binding sites. The silver ion inhibits sodium/potassium ATPase activity, resulting in reduced absorption of sodium and chlorine ions. Thus, Gill is the main site of acute toxic action of the silver ion..