Toxicity induced alterations as biomarker of environmental pollution

Over the past few decades dye contamination of aquatic systems has attracted the attention of several investigators both in the developed and developing countries of the world. A large quantity of these dyes enters aquatic bodies from time to time because a substantial amount of a dye (10-15% unbound dyes) is lost in the effluent during dyeing processes. In return the aquatic bodies end up being the final destination of a large quantity of wastes from these sectors. Waste waters from dye manufacturing, paper, leather and textile industries bring tons of dyes into the aquifers, most of which are highly toxic to the flora and fauna of the receiving water bodies. Scanning electron microscopic observations were made for the changes in the surface ultra morphology of gills of Cirrhinus mrigala on exposure to lethal (0.1, 0.2, 0.4, 0.6 and 0.8 mg/L dye) doses of Basic Violet-1 (an important textile and hair colorant; CI: 42535, Trade nameMethyl Violet-2B). Present study was taken up as insufficient data exist regarding safety of this dye. The dye was observed to be cytotoxic in nature during the acute (96h) exposure to lethal doses. The dye caused reduction or complete loss of microridges, increase in mucous openings and Chapter contents Introduction .................................................................................................................... 174 Materials and methods ...................................................................................................... 175 Experimental model ................................................................................................................ 175 Exposure period and observations ................................................................................... 176 Results and discussion ...................................................................................................... 176 Conclusion ..................................................................................................................... 181 References ...................................................................................................................... 181