Abstract
The aim of the present study is to evaluate the concentration of heavy metals in water and in sediment of Uppanar estuary, located at Cuddalore district, Tamil Nadu, India. The water and sediment samples were collected periodically from estuary during post monsoon, summer, pre monsoon and monsoon seasons from three different stations viz; station 1, station 2 and station 3. The samples were analyzed for the levels of cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn) and nickel (Ni) by using standard methods. A significant seasonal variation (P< 0.05) was observed in the levels of all heavy metals in three stations. In water, heavy metals level was found to be in the order of Zn> Cu > Pb> Cd >Ni, whereas in sediments it was found to be in the order of Zn> Cu> Cd> Pb> Ni. The present results clearly indicated that the levels of Zn, Cu, Cd and Pb were exceeded the prescribed limits of WHO and also showed that both the samples were contaminated with heavy metals. The maximum levels of heavy metals in both the samples were noticed in S2 followed by S3 and S1. The elevated concentration of metals in this region may be due to location of this station nearer to the SIPCOT industries, where mixing of industrial effluents with estuary followed by river runoff, which contribute much of industrial and land derived materials along with domestic, municipal, and agricultural wastes loaded with pesticides. In addition to the continuous contribution of pollutants due to human activities, industries may also have a significant contribution of these metals in all the stations. Hence, it is recommended that, possible measures should be taken to minimize the levels of heavy metals in this study area.