title: Exposure of composite tannery effluent on snail, Pila globosa: A comparative assessment of toxic impacts of the untreated and membrane treated effluents.
abstract: Effluent from tannery industries can significantly affect the aquatic environment due to the presence of a variety of recalcitrant components. The present study focuses on a comparative assessment of the toxic impacts of an untreated tannery effluent and membrane treated effluents using snail, Pila globosa as an aquatic model. Composite tannery effluent collected from a common effluent treatment plant was selected as the untreated effluent. To investigate the effect of treated effluents on the aquatic organism the effluent was treated by two ways, viz. a single stage microfiltration (MF) using ceramic membrane and a two-step process involving MF followed by reverse osmosis (RO). The whole body tissue, gonad and mantle of P. globosa were subjected to enzyme assays like superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GSH-GPx), glutathione S- transferase (GST), etc. for assessing toxic impact. Changes in the biochemical parameters like protein, carbohydrate and amino acid were observed including histological studies of gonad and mantle tissue upon treatment with tannery effluents. To examine potential DNA damage due to the exposure of the effluent, comet assay was conducted. The study revealed that with an exposure to the untreated effluent, activity of the antioxidant enzymes increased significantly while the protein and carbohydrate content reduced largely in the whole body tissue, gonad as well as mantle tissues of P. globosa. Histological study indicated considerable damage in the gonad and mantle tissues following exposure to the untreated effluent. Comet assay using hemolymph of P. globosa following exposure to tannery effluent, showed significant genotoxicity. Interestingly, compared to the untreated effluent, damaging effect was reduced in molluscs tissues when exposed to MF treated effluent and even lesser when exposed to MF+RO treated effluent. Apart from the reduced activities of oxidative stress enzymes, the protein, amino acid and carbohydrate content of molluscs exposed to both of the treated effluent were found close to that of control. Comet assay revealed no damage in the DNA for MF and MF+RO treated effluent indicating that the membrane based treatment procedure restores environmental condition to control level.
authors.affiliation: Ceramic Membrane Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032, India.
authors.forename: Priyankari
authors.initials: P
authors.lastname: Bhattacharya
authors.affiliation: Drug Development Diagnostics & Biotechnology Division, CSIR-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Snehasikta
authors.initials: S
authors.lastname: Swarnakar
authors.affiliation: Department of Environmental Science, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, India.
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Mukhopadhyay
authors.affiliation: Ceramic Membrane Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032, India. Electronic address: sourja@cgcri.res.in.
authors.forename: Sourja
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects; D004784:Environmental Monitoring / Q000379:methods; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007220:Industrial Waste; D018384:Oxidative Stress / Q000187:drug effects; D012908:Snails / Q000201:enzymology* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D013633:Tanning; D014877:Water Pollution, Chemical / Q000009:adverse effects*
chemical_list: D000975:Antioxidants; D007220:Industrial Waste; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase
keywords: Membrane treatment; Oxidative stress; Pila globosa; Tannery effluent; Toxicity