Environmental Management
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/3753
Browse
2 results
Search Results
Item Assessing toxicity of two industrial zone effluents reaching Kelani River,Sri Lanka(Journal of national science foundation Sri Lanka, 2018) Hemachandral, C.K.; Pathiratne, A.Evaluation of the effcaey of waste treatment technologies of industnal waste is a major challenge for sustainable industrial development world-wide. Hence, new strategies are needed to assess interactive toxic effects of all substances present in the treated waste. This study assessed potential toxic hazards of treated effluents discharged from common wastewater treatment plants of two mclustrlal zones located in the Kelani River basin using Allium cepa (common onion) test system. The results showed that the final effluents of both industrial zones under undiluted and diluted (1 IS v/v) conditions mduced cytotoxrcity on all occasions, with evidence of significant (p < 0.05) mlto-depression In the root meristem and retardation of root growth in A. cepa. Genotoxlc hazard of the effuents was evident by frequent mcrease of nuclear and chromosomal abnormalltles, and occasional development of micronuclei in the root merlstem. Dilution of the effluents to 1 reduced the genotoxic effects generated in A. cepa roots by the final effuents_ The results revealed that waste treatment technologies m these two mdustnal zones need to be upgraded m order to ehmmate cytotoxlc and genotoxrc hazards associated with the treated effuents_ The results highlight the importance of incorporatmg practically feasible bioanalytical tools such as A. cepa root based test system on a regular basis for evaluating the efficacy of waste treatment technologies.Item Biomarker responses of Nile Tilapia (Oreochromis niloticus) exposed to polluted water from Kelani river basin, Sri Lanka: Implications for biomonitoring river pollution(Sri Lanka J. Aquat. Sci, 2018) Ruvinda, K.M.S.; Pathiratne, A.Biomarkers can be considered as early warning signals for potential adverse effects on the biota. The present study examined the feasibility of using selected biomarker responses of a model fish, Oreochromis niloticus under laboratory exposure approach for identification of potential biological impacts of pollution in Kelani River. Laboratory acclimated O. niloticus were exposed under static-renewal conditions to water samples collected from selected sites of the Kelani River basin with different anthropogenic influences and biomarker responses (brain and muscle cholinesterase activities for neurotoxicity, erythrocyte micronuclei and nuclear abnormalities for genotoxicity and liver histology for hepatic damage) were evaluated at 5 and 10 days of exposure. Exposed water was physico-chemically characterized using standard analytical methods. The results revealed that exposure of O. niloticus to the water from selected polluted sites which included canals and canal confluences resulted in significant increases (p<0.05) in total erythrocyte nuclear abnormalities, evolution of erythrocyte micronuclei and induction of liver histopathological indices in comparison to the fish exposed to the water from the upper reach of the river (reference site) in most cases and the control fish exposed to the aged tap water in all cases. Brain cholinesterase activity was significantly inhibited (p<0.05) in the fish exposed to the water from the most polluted site compared to the control fish exposed to the aged tap water. Biomarker responses indicated that the fish populations inhabiting the polluted sites in the river may be under stress especially due to hepatic damage and genotoxicity. Evaluation of “effect directed biomarker responses” of the model fish, O. niloticus following laboratory exposure to the contaminated water can be a practically feasible approach for biomonitoring potential pollution impacts associated with the riverine ecosystems.