Document Type : Primary Research paper
PG And Research Department of Zoology, Govt. Arts And Science College, C-Mutlur, Chidambaram-608102, India
Heavy metals are continually released in to the aquatic environment from natural processes such as volcanic activity, weathering of rocks and industrial processes . Today, aquatic animals are exposed to different concentrations of metals in aquatic environments. These metals tend to accumulate in their bodies which could influence all aspects of organisms’ life  The fishes were exposed to different concentrations of lead nitrate, and % mortality was recorded during 24, 48, 72, and 96 hours. The lethal concentration (LC50) value of lead nitrate for 96 hours against H.fossilis were found 157.08 mg/l using the Profit analysis statistical method. The mortality of the fish was directly proportional to the concentration. Assessment of LC50 also revealed that the amount of lead present in freshwater might be lethal to all the aquatic fauna. Exposure to lead affected human health, which accounted for the death of 1.06 million people and loss of healthy life, amounting to nearly 24.4 million. Hence, strict regulations should be imposed to dispose of heavy metals in aquatic bodies to conserve valuable biological diversity.