title: Background concentrations and reference values for heavy metals in soils of Cuba.
abstract: The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.
authors.affiliation: Instituto de Suelos, MINAG, Autopista Costa-Costa km 8½, Capdevila, Boyeros, La Habana, Cuba, investigacion1@isuelos.co.cu.
authors.forename: Mirelys Rodríguez
authors.initials: MR
authors.lastname: Alfaro
authors.forename: Alfredo
authors.initials: A
authors.lastname: Montero
authors.forename: Olegario Muñiz
authors.initials: OM
authors.lastname: Ugarte
authors.forename: Clístenes Williams Araújo
authors.initials: CW
authors.lastname: do Nascimento
authors.forename: Adriana Maria
authors.initials: AM
authors.lastname: de Aguiar Accioly
authors.forename: Caroline Miranda
authors.initials: CM
authors.lastname: Biondi
authors.forename: Ygor Jacques Agra Bezerra
authors.initials: YJ
authors.lastname: da Silva
mesh_terms: D003462:Cuba; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis / Q000592:standards*; D012016:Reference Values; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000592:standards*; D014131:Trace Elements / Q000032:analysis / Q000592:standards
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements