Arsenic (As) is ubiquitous in soils with an average concentration of 5-6 mu g g(-1) in uncontaminated soils. Heavy metals (Pb, Cd, Cu, Zn, Cr, Fe and Al) were determined using flame or graphite-furnace atomic absorption. The mean concentrations (mg kg(-1)) of As (29-500 ppm), Fe (8%), Cu (76 ppm), Pb (52 ppm), Ni (90 ppm), Zn (258 ppm), Mg (1.56%), V (143 ppm), Cr (155 ppm), Cd (< 2), Sb (0.29) and Hg (0.54) in fallow land soils are within the normal range. The mean As (470 ppm), Fe (10.57%) and Mg (1.67 ppm). We have evaluated how soil spectral response of pyrite and hematite is distributed in order to obtain the discrimination among these different soil compositions and their distribution along the dump area. Toxicology and Industrial Health 2009; 25: 343-349.