Dissolved uranium,226Ra in the mine water effluent: A case study in Jaduguda

Uranium (238U) bioaccumulation and its persuaded alterations on hematological, serological and histological parameters in freshwater fish Pangasius sutchi

The early biomarkers for the hematological, serological and histological alterations due to the effect of ½ and ¼ LC₅₀ of ²³⁸U in different organs in freshwater fish Pangasius sutchi for water-borne ²³⁸U accumulation was investigated. The toxicological data due to ²³⁸U accumulation on the hematological parameters such as hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and hematocrit (Hct) to evaluate the oxygen carrying capacity has been indicated as the secondary response of the organisms. The biomarkers of liver damage were determined as by Serum Glutamic Oxaloacetic Transaminase (SGOT), Serum Glutamic Pyruvic Transaminase (SGPT), Alkaline Phosphatase (ALP), γ-Glutamyl Transferase (γ-GT). Similarly, the renal biomarkers of kidney damage were accessed by creatinine, uric acid, triglycerides, and cholesterol. The decrease in hemoglobin in the experimental group due to disturbed synthesis of hemoglobin was directly proportional to the concentration and exposure duration of ²³⁸U. The histological studies proved that liver and gills are the target organ for ²³⁸U toxicity. The extensive histological lesions were observed in various tissues due to oxidative stress by the accumulation of ²³⁸U, and the ²³⁸U toxicity in the organs was in the order of Gills<liver<brain<muscle. This study can be useful indicators of ²³⁸U toxicity to assess fish health in Uranium (²³⁸U) biomonitoring programs.

Uranium (238U)-induced ROS and cell cycle perturbations, antioxidant responses and erythrocyte nuclear abnormalities in the freshwater iridescent shark fish Pangasius sutchi

The strategic plan of this study is to analyze any possible radiological impact on aquatic organisms from forthcoming uranium mining facilities around the Nagarjuna Sagar Dam in the future. The predominantly consumed and dominant fish species Pangasius sutchi, which is available year-round at Nagarjuna Sagar Dam, was selected for the study. To comprehend the outcome and to understand the mode of action of ²³⁸U, the fish species Pangasius sutchi was exposed to ¼ and ½ of the LC₅₀ doses of waterborne ²³⁸U in a static system in duplicate for 21 days. Blood and organs, including the gills, liver, brain and muscles, were collected at different time periods-0h, 24h, 48h, 72h, 96h, 7, days 14days and 21 days-using ICP-MS to determine the toxic effects of uranium and the accumulation of ²³⁸U concentrations. The bioaccumulation of ²³⁸U in P. sutchi tissues was dependent on exposure time and concentration. The accumulation of uranium was, in order of magnitude, measured as gills>liver>brain>tissue, with the highest accumulation in the gills. It was observed that exposure to ²³⁸U significantly reduced antioxidant enzymes such as superoxide dismutase, catalase, and lipid peroxidase. The analysis of DNA fragmentation by comet assay and cell viability by flow cytometry was performed at different time intervals. DNA histograms by flow cytometry analysis revealed an increase in the G2/M phase and the S phase. The long-term ²³⁸U exposure studies in fish showed increasing micronucleus frequencies in erythrocytes with greater exposure time. The higher the concentration of ²³⁸U is, the greater is the effect observed, suggesting a close relationship between accumulation and toxicity. A possible ROS-mediated ²³⁸U toxicity mechanism and antioxidant responses have been proposed.