“…The identified metals could be divided into two categories according to their role in plants: essential metals (nutrients required by the plant for its development): Al, As, Cr, Ni, Se, and Zn (Prieto et al, 2009;Marin et al, 2010;Toneatti and Rivera 2006) and non-essential metals (nutrients that do not have a biological function): Ba, Hg, Pb, and Tl (Prieto et al, 2009;Lamb et al, 2013).…”