This study aimed to investigate the bioaccumulation and elimination of lead (Pb) in Fejervarya limnocharis frogs as well as to determine the genotoxic effects of direct Pb exposure at different concentrations and lengths of time. Four varying concentrations (0, 5, 10 and 20 mg.L-1) of lead acetate (Pb(CH3COO)2) solutions were injected intraperitoneally into F. limnocharis. The concentration of Pb in the water samples used to house the frogs and the concentration of lead in frog muscle tissues were analysed at 24, 48 and 72 hours after injection by inductively coupled plasma optical emission spectrometry. Pb was detected at a level that exceeded the standard (0.03 mg.kg-1) in all samples of frogs injected with Pb. The water samples indicated that the Pb concentrations were significantly different from the control (p < 0.05), except for the 5 and 10 mg.L-1 concentrations after 24 hours groups and 5 mg.L-1 concentration after 48 hours group. Only the concentration of the water in the 20 mg.L-1 for 72 hours group exceeded the standard (0.05 mg.L-1). Genetic differentiation was studied by inter simple sequence repeats (ISSR) with dendrogram construction and analysis of genetic similarity (S) for each duration of exposure. A total of 1158, 1205 and 1277 bands were generated by ISSR for the 24, 48 and 72 hours groups, respectively. In each dendrogram, individual injections with the same Pb concentration clustered together, and it appeared that higher concentrations resulted in greater genotoxicity. Genotoxicity was concentration- and time-dependent, with a correlation between the concentration and S-value for the 72 hours group (R2 = 0.77, p < 0.05). In addition, this study could provide a basic application to develop F. limnocharis as a biomarker for Pb contamination by measuring genotoxic consequences.

The present study deals with the genotoxic effect of iron oxide nanoparticles treated tannery effluent on zebrafish Danio rerio. The chemical co-precipitation method was used for the synthesis of iron oxide nanoparticles which were characterized by SEM, EDAX, XRD, FTIR and VSM. Physico-chemical characteristics of tannery effluent were also estimated. Iron oxide nanoparticles were used as nano-adsorbents in reducing the toxic substances present in tannery effluent. Behavioural studies and genotoxic effect on zebrafish exposed to different concentrations of iron oxide nanoparticles treated tannery effluent and control (raw tannery effluent) were carried out. Biochemical composition such as protein, carbohydrate and lipid were estimated in the muscles and gills of zebrafish on 14th day after exposure. SEM images of iron oxide nanoparticles were observed at 5 μm and 10 μm which were spherical. EDAX spectrum recorded on synthesized iron oxide nanoparticles was identified in 7 peaks. FT-IR spectrum of iron oxide nanoparticles was analysed in the range of 500-4000 cm-1 and spectral bands were observed. Physico-chemical parameters of treated tannery effluent were decreased as the different concentrations of iron oxide nanoparticles increased. 200, 225 and 250 ppm treated tannery effluent were selected for median lethal concentration. No mortality was found in both control and iron oxide nanoparticles treated tannery effluent. The number of micronuclei was increased with increasing concentration of iron oxide nanoparticles when compared to control. Biochemical characteristics such as protein, carbohydrate and lipid in muscle and gills of zebrafish were higher in T2 (225ppm) than control and other concentrations. From this, it can be concluded that iron oxide nanoparticles can be used as nano-adsorbent in treating tannery effluent for effective removal of toxic substances.

The pollution of the river by man-made sewage and waste disposal is not only harmful to animals and plants in it but also for animals higher in the food chain including those close to the food chain. Water is the most vital natural substance, as it plays a role in nearly every aspect of human life. Therefore, there is a great need to ensure that the water used by humans should not contain hazardous substances. Water quality is directly linked to biological life. The Nag River flows from the Lava village of north Ambazari Lake and flows into the center of Nagpur city. As a result of rapid and unstoppable development, significant changes have taken place in the water quality of the Nag River. Because the Nag River’s water is frequently used for irrigation, it should be tested for cytotoxicity and genotoxicity. Since the rate of cancer and genetic disorders has recently increased in the Nagpur region, the Nag River’s water could be a source of carcinogens in the food chain, affecting the population. This study was conducted to analyze the impact of water collected from various points of the Nag River using Allium cepa as a model organism. The results of this study showed that all water samples from the Nag River cause a cytotoxic effect (20-23%) and genotoxic effects (23-28%) in Allium cepa cells. Therefore, before the use of Nag River water, it must be treated to diminish its harmful effect.