The Reference Quality Values (RQV) for heavy metals in soils are quite heterogeneous around the world. In Brazil, few studies establishing such values have been published. In the absence of VRQ of heavy metals in soils established for the specific conditions of the State of Espírito Santo, international generic values or values developed for other States are used. However, it should be noted that the use of these values can lead to erroneous assessments, due to the regional differences in technical and environmental variables, particularly in terms of geological, water and soil conditions. The purpose of this study was to determine heavy metal concentration in soils of Espírito Santo State, and to investigate the major factors involved in the distribution of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Ti, V and Zn in soils of the river basins of Riacho, Reis Magos and Santa Maria da Vitória. Based on this information RQV were established. Total concentrations were determined by microwave oven digestion, according to the SW-846 3052 method of the Environmental Protection Agency (USEPA), and by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The mean concentrations of most heavy metals studied were, in general, lower than reported in international references. Cadmium concentrations were below the detection limit (DL) in all samples. The RQVs found from the percentile 75 for As (< 12.83), Cd (< 0.13), Co (10.21), Cr (54.13), Cu (5.91), Mn (137.80), Mo (1.74), Ni (9.17), Pb (< 4.54), V (109.96), and Zn (29.87), in mg kg-1; were similar to or lower than those adopted in Sao Paulo state and in Brazilian, in general.
potentially toxic elements; micronutrients; natural concentration of heavy metals in soil
