Teores de elementos tóxicos e micronutrientes em fertilizantes e corretivos comercializados no Nordeste do Brasil

Abstract

Heavy metals are chemical elements with a density greater than 6 g cm-3 and among these metals, there are toxic elements cadmium (Cd), lead (Pb) and chromium (Cr). In soil, the application of fertilizers and heavy metals can add as impurities constituents of these inputs, contributing to soil contamination. Several countries, including Brazil, regulate the contents of these elements in fertilizers and in order to protecting the health of the consumer, and also those who work directly with this product. In this sense, the objective of this study was to determine the concentration of Pb, Cd and Cr in several fertilizers and limes marketed in the Brazilian Northeast and assess their potential for contamination of agricultural soils. Therefore, 24 samples of 26 samples of fertilizers and lime were digested by the method 3051A (USEPA), using a microwave oven and after obtaining the extracts, the metals Cd, Pb and Cr were determined by atomic absorption spectrophotometer, flame technique (air- acetylene). In addition, different samples of fertilizer multielement SRM 695 (National Institute of Standards and Technology - NIST), and white spikes. The recoveries of spikes and certified samples were considered suitable. Results indicate that phosphate fertilizers have higher contents Cd, Pb and Cr in relation to lime and that its use is not appropriate offers risks to the agricultural and consumer end, simply only adequate monitoring in successive applications of phosphate studied natural, for purposes of environmental quality.