Poll Res. 36 (1) : 48-58 (2017) Copyright © EM International ISSN 0257–8050 *Corresponding author’s email: s.jkumar1@gmail.com INTRODUCTION Metals are very much essential in trace amount for sustaining life but in higher concentration cause severe predicament (Hsu et al., 2006; Rashad et al., 2007). Heavy metals are the elements of transition series with relatively high density (Duffus, 2002). These metals are found widely in the earth’s crust and are non-biodegradable in nature (Rajmohan et al., 2014). They exist in different chemical species, transform to others and easily transported to different ecosystems and bio-accumulate (Duffus, 2002; Sun et al., 2013). Heavy metals enter into a various section of the environment through different ways. Some of the natural phenomena like a volcanic eruption, flooding, processes of pedogenesis, forest fires, landslides, dust storms, and anthropogenic activities, including industrial processes, mining, urbanization, and intensive agricultural practices have a significant contribution (Elgawad et al., 2007; Nasir and Harikumar, 2011). It is understood from different studies that HEAVY METAL CONTAMINATION IN SEDIMENTS OF KANWARJHEEL WILDLIFE SANCTUARY, BIHAR, INDIA AJEET KUMAR SINGH AND S. JAYAKUMAR* Environmental Informatics and Spatial Modelling Lab (EISML) Department of Ecology and Environmental Sciences, School of Life Sciences, Pondicherry University, Pondicherry, India (Received 29 March , 2016; accepted 30 May, 2016) ABSTRACT The accumulation of heavy metals in sediments of water bodies are of serious concern due to toxic and non-biodegradable nature. In this study, sediment core samples of Kanwarjheel wildlife sanctuary were analysed to understand the distribution of heavy metals. The average concentration of heavy metals was found in a sequence of Fe > Mn > Cr > Zn > Cu > Ni. The vertical distribution of these metals in sediments has shown considerable variations in their concentration. Except Mn, all other metals exceed the value of low effect level prescribed by United States Environmental Protection Agency. The geo-accumulation index (I geo ), enrichment factor (EF) and contamination factor (CF) was used to estimate the sediment quality. The average values of I geo , EF and CF were ranged between -0.50 to 0.59, 0.34 to 3.76 and 0.47 to 5.80 respectively. The intensive agriculture practices and continuous discharge of sewage and industrial wastes have significantly influenced the metal concentration in the study area. KEY WORDS : Kanwarjheel wildlife sanctuary, Heavy metals, Sediment quality, Geo- accumulation index, Enrichment factor, Contamination factor. intensive anthropogenic activities have altered the quality status of many naturally existing aquatic ecosystems in Indian Sub-continent (Singh et al., 2002; Purushothaman and Chakrapani, 2007; Pandey et al ., 2010; Parth et al ., 2011; Nasir and Harikumar, 2011; Banerjee et al., 2012; Rahman et al., 2012; Dhanakumar et al., 2013; Mohan et al., 2013; Raju et al., 2013; Talekar et al., 2014; Rajmohan et al., 2014; Kumar and Ramanathan, 2015). Wetland sediments retain different heavy metals in high concentration for a longer time, to protect water quality and existing ecologies of river, lakes and/or ponds (Sasaki et al., 2003; Bai et al., 2009; Bai et al., 2010; Bai et al., 2011). These sediments are also believed as habitat and major nutrient source for different aquatic flora and fauna (Nasir and Harikumar, 2011). So, assessments of sediments of the aquatic ecosystem can make a better understanding about adverse impacts of contaminants to wildlife and dependent human population. Heavy metal contaminations are known for