Copyright © 2018 Ram Proshad et.al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Advanced Geosciences, 6 (1) (2018) 108-116 International Journal of Advanced Geosciences Website: www.sciencepubco.com/index.php/IJAG doi: 10.14419/ijag.v6i1.9791 Research paper Assessment of heavy metals with ecological risk of soils in the industrial vicinity of Tangail district, Bangladesh Ram Proshad 1 *, Md. Saiful Islam 1 , Tapos Kormoker 2 1 Department of Soil Science, Patuakhali Science and Technology University, Dumki, Patuakhali-8602, Bangladesh 2 Department of Emergency Management, Patuakhali Science and Technology University, Dumki, Patuakhali-8602, Bangladesh *Corresponding author E-mail: ramproshadpstu03470@gmail.com Abstract This study was conducted to assess the ecological risk of heavy metals in soils collected from the industrial vicinity of Tangail district in Bangladesh. In this study, the levels of six heavy metals namely chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) in 15 sampling sites around the industrial vicinity of Tangail district in Bangladesh were assessed. The mean concentration of Cr, Ni, Cu, As, Cd and Pb in studied soils were 11.56, 23.92, 37.27, 6.11, 2.01, and 17.46 mg/kg, respectively. Certain indices, includ- ing the enrichment factor (EF), contamination factor (C i f), geoaccumulation index (Igeo), pollution load index (PLI), toxic unit analysis, and principal component analysis (PCA) were used to assess the ecological risk. The enrichment factor of all the studied metals for all sampling sites were in the descending order of Cd > Cu > As > Pb >Ni > Cr. The contamination factor values revealed that the studied soils were highly impacted by Cd. The pollution load index (PLI) values of Cd were higher than 1, indicating the progressive deteriora- tion of soil due to Cd contamination. In the context of potential ecological risk (PER), soils from all sampling sites showed moderate to very high potential ecological risk. Keywords: Heavy Metal; Potential Ecological Risk; Industrial Vicinity; Bangladesh 1. Introduction For the survival of human life on the planet, soil act as a dynamic natural resource and regarded as the key receiver of the persistent pollutants like heavy metals (Luo et al. 2007, Karim et al. 2014, Islam et al. 2015, Proshad et al. 2018). Soil pollution by heavy metals is a global problem that is highly predisposed by human- induced activities (Han et al. 2002, Vare 2006, Islam et al. 2015). Nowadays, soil pollution by heavy metals has become an envi- ronmental issue in both developed and developing countries all over the world (Islam et al. 2015, Sun et al. 2010). Heavy metals such as nickel (Ni), chromium (Cr), copper (Cu), arsenic (As), cadmium (Cd), and lead (Pb) have been considered as the most toxic elements in the environment by the US Environment Protec- tion Agency (EPA) (Luo et al. 2007, Lei et al. 2010, Proshad et al. 2017). In recent decades, there has been a major concern regarding soil pollution by various heavy metals due to rapid industrializa- tion and urbanization, especially in developing countries (Islam et al. 2015, Sun et al. 2010, Chen et al. 2010, Islam et al. 2014, Ah- med et al. 2015). Heavy metals are of great concern due to their toxicity, non-biodegradable properties and accumulative behaviors (Islam et al. 2015, Islam et al. 2014). Heavy metals may initiate in soils around the industrial area from various sources of which are industrial activities, power generation, manufacturing, waste spills, or fossil fuel burning and waste disposal (Luo et al. 2007, Karim et al. 2014, Wei and Yang 2010, Li and Feng 2012, Rodri- guez et al. 2014, Islam et al. 2015). The accumulation of heavy elements in soils is a great concern due to their potential environ- mental risk and harmful effects on soil ecosystems (Islam et al. 2015, Cui et al. 2004, Li et al. 2009, Yu et al. 2012, Yuan et al. 2014). To assess the ecological risks of heavy metals in soil dif- ferent methods have been widely used, such as enrichment factor (EF), contamination factor (C i f), toxic unit analysis, and geoaccu- mulation load index (Igeo) (Islam et al. 2015, Rashed 2010). The enrichment factor of an area indicates the relative enrichment in any pollutant when compared to pre-industrial soils from the same environment (Islam et al. 2015, Sayadi and Sayyed 2011, Hower et al. 2013, Dias et al. 2014). As soil contamination arising from industry, the study area has raised attention due to its environmen- tal pollution which is facing serious threats due to heavy metals pollution originated from the rapid development, congestion, and activities from industries (Islam et al. 2015, Islam et al. 2014). Several studies have stated the concentration of heavy metals in the industrial area soils in Bangladesh (Islam et al. 2015, Ahmad and Goni 2010, Rahman et al. 2012). Therefore, in this study, the variations of heavy metals in soils of different soil sampling sites were studied. The objective of this study was to assess the ecolog- ical risk of heavy metals in soil in the industrial vicinity of Tangail district in Bangladesh. 2. Materials and methods 2.1. Study area and sampling The samples were collected from Tarutia, Tangail Sadar Upazila of Tangail district, Bangladesh (Figure 1). Tangail district area is 334.26 km² and situated at the middle part in Bangladesh. Tangail Sadar Upazila is highly densely area in Bangladesh and population density is 1,100/km2 in Tangail district. The study area is situated between Tangail Sadar is located at 24.2500°N to 89.9167°E. Tangail as an industrial vicinity of Bangladesh possesses highly vulnerable to environmental pollution nowadays. There are several