Heavy metals in sediment ecosystem of Bhavans College Lake of Andheri, Mumbai

The present study was initiated to understand the accumulation of toxic heavy metals in sediments of Bhavan's College Lake of Andheri, Mumbai. The study was performed for a period of one year starting from June 2011 to May 2012 to quantify the toxic heavy metals like Cu, Pb, Cr, Ni, Fe, Hg, As and Cd by atomic absorption spectroscopy technique coupled with cold vapour technique (for Hg analysis) and hydride generation technique(for As analysis). It was observed that the yearly average concentrations of these heavy metals in lake sediments were 0.53, 0.25, 0.42, 0.43, 4.6, 0.14, 0.12 and 0.11 ppm respectively which were above the WHO limits for aquatic life and CPCB limits for inland surface water. These heavy metals accumulated in lake sediments may enter the water thereby creating threat to aquatic life. They may enter the food chain through biomagnifications and may create adverse effect on human health. It is expected that in addition to the water analysis which is practiced for years, sediment analysis performed in the present investigation will help in evaluating quality of the total ecosystem of the lake. It will also provide environmentally significant information about natural and anthropogenic influence on the water body.