“…A number of techniques have been developed over the past two decades, and are still used to estimate HMs bioavailability in soil; including diffusive gradient in thin films (Agbenin and Welp, 2012;Menegário et al, 2017;Parker et al, 2016;Ren et al, 2015), ion exchange (Ge et al, 2005;Qian and Schoenau, 2002), single-step extractions (R. Y. Pinto et al, 2015;Sakan et al, 2016), and sequential extractions (Cox et al, 2013;Fernández-Ondoño et al, 2017;Palumbo-Roe et al, 2013;Reis et al, 2014;Sungur et al, 2014). Sequential extractions, in particular, are simple low cost methods, that can be applied to different soil types (Rosado et al, 2016), and can help understanding HMs and metalloids leachability, solubility, and mobility (Kaakinen et al, 2015), providing the most information about the fate, transport, and behaviour of HMs in soil.…”