2013 Conference of the International Medical Geology Association (25–29 August 2013)

Paper No. 7
Presentation Time: 12:00 PM-11:55 PM


SILVA, Cassio Roberto, Territorial Management Department, Geological Survey of Brazil, Rua da passagem, 07 apto. 1002 - Botafogo, Rio de Janeiro, 22290030, Brazil and VIGLIO, Eduardo Paim, Territorial Management Department, Geological Survey of Brazil, Av. Pasteur, 404 -Urca, Rio de Janeiro, 22290240, Brazil, cassio.silva@cprm.gov.br

The state of Minas Gerais (MG) is located in southeastern Brazil, occupies an area of 587,464 km². A total of 1,044 soil samples were collected in regional square grid of approximately 25x25km. The soil was to pulverized 150# and analyzed 52 elements by ICP-MS and including macronutrients such as Ca,Na,P,Mg and S; micronutrients such as B,Co,Cr, Cu,F,Fe,K,Mn,Mo,Ni, Se,Sn and Zn and toxic such as Al,Ag,As,Ba,Be,Cd,Hg,La,Li,Pb,Sb, Te,Ti, Tl, U and W.

The results show that the macronutrients, Ca (median=0.0001%, max=20%), Mg (median=0.02%, max=12%), Na (median=0.0001%, max=0.11%), P (median=188ppm, max=6000ppm) and S (median=0.0001%, max=0.16%), occur in deficient levels only in small areas of MG. Regarding micronutrients, Zn (median=11ppm, max=190ppm) and Mn (median=99ppm, max=6312ppm) show both areas of deficiency and large areas with values that are considered to be harmful to human health. The values of Co (median=1.9 ppm, max=81ppm), Cu (median=2.55 ppm, max=216ppm), Ni (median=7.8 ppm, max=399ppm), Se (median= 0.01 ppm, max=12ppm) and V (median=74.5 ppm, max=740ppm)show that 30% of the MG area has concentrations above the limits permitted by health agencies. But, the elements of greater concern in terms of concentrations high above the guidelines are the Cr (median=39 ppm, max=2167ppm) and Mo (median=0.62 ppm, max=7.30ppm). While Cr has concentrations above the soil quality guidelines in 30% of the MG area, Mo shows elevated concentrations in 40% of the state.

Data on macro (Ca, Mg, K, P and S) and micronutrients (Co, Cu, Fe, Mn and Zn) show that the state of MG has soils with high natural fertility in about 80% of its territory; deficiencies for micronutrients B, Ni, Se, Sn and V occur mainly in the northwestern part of the state. Hazardous areas of soil contamination by toxic elements are found in a number of regions within MG, such as Al in the northeast, As in the Iron Quadrangle gold district (east-central part of the state), and the elements Cr in the Triangulo and Zona da Mata and Mo into two large bands in the western and eastern regions of the state.