Assessment of Heavy Metals in Summer & Winter Seasons in River Yamuna Segment Flowing through Delhi, India

Abstract

In the present investigations, monitoring of seasonal variations in the concentrations of heavy metals (Pb, Fe, Zn, Mn, Cd, Co, Cu, Cr and Ni) in the Yamuna river water flowing through Delhi have been carried out during the year 2011. Yamuna River, Delhi segment has been chosen for this study as Delhi is a major industrial centre in the country, leading to addition of loads of contaminants into the river Yamuna.  For this purpose, sampling was done from ten selected study sites (most likely to be affected by industrial & anthropogenic activities) during two seasons i.e. summer (May) and winter (January). The technique of Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) was used to determine the concentration of heavy metals in the water samples in both the seasons. Results have shown wide variations in the heavy metal levels varying from high concentration during summer and low concentrations during winter season. The concentrations of Pb, Cd, Cr, Cu, Zn and Co were found to be under the permissible limits of ICMR, CPCB, WHO and EPA. Elevated concentrations of Fe, Ni & Mn were found at Boat club, Yamuna Bazar, Nigambodh Ghat, Delhi old Bridge, ITO, Nizamuddin Bridge & Mayur Vihar. Also, Pb, Cd, Cu and Co have shown significant variation (p<0.05) in their concentration between summer and winter seasons, with less accumulation during winter and high during summers. High heavy metal concentration during summer may be attributed to increased water temperature during summer that may result in increased metal toxicity. The high levels of heavy metal at these sites can be related to the untreated industrial discharge, lead battery-based industrial units, vehicular pollution & surface run-off from contaminated areas.