DISTRIBUTION AND OCCURRENCE OF MULTI-ELEMENT AND PHARMACEUTICAL POLLUTANTS IN AN URBAN WETLAND OF ASSAM, INDIA

“Urban wetland” are unique ecosystems as many of these harbour a wide variety of organisms and at the same time provide a number of services to the associated urban area, including protection from flash floods and more importantly groundwater recharge and water pollution control. Recent study of an important urban wetland, the Deepor Beel a Ramsar site of Assam, India revealed a steady state of its degradation. Groundwater, surface and sediment core samples were collected; trace element (Cu, Ni, Zn, Pb, and Cr) analyses revealed that Pb levels exceeded the prescribed limit for drinking water. Pilot scale examination of the pharmaceutical and personal care products (PPCPs) levels in the lake water showed the presence of five important PPCPs, which in the decreasing order of their concentration were Caffeine> Acetaminophen≥ Theophylline> Carbamazepine> Crotamiton. Concentration of caffeine and carbamazepine were found to be higher than the limit of detection (LOD). Multivariate analyses of the analytical data via principal components analysis (PCA) and hierarchical cluster analysis (HCA) emphasized the importance of anthropogenic influence. The sewage origin of trace metals was revealed by the clustering of Cu, Zn, Cr and Ni with EC, salinity and TDS in HCA. However, Pb was separately clustered with Cl^- and SO₄^2- pointing to a common source in grey water, which could include bleaching powder, soaps and detergents and the corrosion of lead lining in pipes. We conclude that this study points to an increased involvement of anthropogenic activities linked to the unplanned urbanization of the adjacent Guwahati city and encroachment of the lake area itself.