Histopathological Alterations in Muscle, Liver and Gill Tissues of Zebra Fish Danio Rerio due to Environmentally Relevant Concentrations of Organochlorine Pesticides (OCPs) and Heavy Metals

The study monitored the toxicity of environmentally relevant concentration of pesticides and metals in zebra fish Danio rerio. Zebra fish were exposed to environmentally relevant concentration of pesticides and metals for a period of 14 days. The individual and the combined toxicity of pesticides and metals were evaluated. The pesticides and metals treated groups showed histopathological alterations in the muscle, liver and gill tissues. Significant alterations were seen in liver and gill compared to muscle tissue. Among groups, the changes in group III (pesticides treated) were severe followed by group II (metals treated) and then the group IV (metals and pesticides treated, combined toxicity). Splitting of muscle fibers and necrosis was observed in muscle tissue. In the liver tissues severe damages such as dilation and congestion of blood sinusoids, cytoplasmic vacuolation and necrosis were observed. Pronounced hyperplasia and well defined necrosis was observed in gill. In conclusion the evidence of pathological alterations in gills and livers of zebra fish Danio rerio appeared to be a useful bio-marker to assess the impact of combined toxicity of pesticides and metals.