First report on: Acute toxicity and gill histopathology of fresh water fish Cyprinus carpio exposed to Zinc oxide (ZnO) nanoparticles

Nanotechnology is an advancing field of research which has revolutionized all industrial needs, such as medical, environmental and other industrial applications. Despite the rapid progress and early acceptance of nanotechnology, the potential for adverse health effects due to prolonged exposure at various concentration levels in humans and the environment has not yet been studied. With the widespread application of nanomaterials, numerous nanoscale products might consequently be released into aquatic environments and elicit an impact not only on one particular ecosystem but also on human health. The environmental impact of nanomaterials is expected to increase dramatically in near future. Zinc oxide (ZnO) nanoparticles have wide ranging applications in a diverse array of industrial and consumer products, ceramic manufacturing, paint formulation, sunscreen and hair care products. Toxicological studies indicate that ZnO nanoparticles have adverse impacts on human health and environmental species. Hence it is due process to characterize the health and safety aspects of ZnO nanoparticles to humans and environment. The present study has been conducted to develop first hand information on the acute toxicity (LC50) and gill histopathology of ZnO nanoparticles in fresh water fish, Cyprinus carpio. It was found that the 50% lethal concentration (LC50) of ZnO nanoparticle for C. carpio is 4.897 mg/L. Gill histopathological damage exposed to sub- lethal concentration of ZnO nanoparticles for 21 d are also discussed in this paper.