“…Nevertheless, several studies have reported As levels in hair and nail along with water and soil of different areas (Tsuji et al, 2005;Chiou et al, 1997;Lin et al, 1998) but very few studies has reported their association with dust and air particles (Huang et al, 2014;Tsuji et al, 2005). Similarly, a number of studies have reported As concentrations in human nail and hair, and reported them as an effective bio-monitoring tool for As exposure (Cottingham et al, 2013;Rakib et al, 2013;Samanta et al, 2004;Sanz et al, 2007;Anwar, 2005), due to their keratin tissue composition, containing high cystein residues that have affinity for diverse metals transported via body fluids, thus become part of these metabolic inactive tissues (Tsuji et al, 2005 andHuang et al, 2014). Hence, once As is accumulated into these non-invasive tissues, can easily be collected and used to monitor past As exposure into human body (Gualt et al, 2008;Hinwood et al, 2003).…”