DETERMINATION OF HEAVY METAL CONTAMINATION IN SOILS SURROUNDING THE ELECTROCHEMICAL ENTERPRISE OF SAGUA

Abstract

Soil contamination by heavy metals, which suffer from low degradation and are therefore considered as persistent bioaccumulative toxins, represents a marked risk to human health and ecosystems. The aim of this work is to determine the mercury (Hg), cadmium (Cd) and lead (Pb) concentration in 20 samples of soils from the surroundings of the Electrochemical Enterprise of Sagua, by means of the joining of techniques of digestion and detection with Spectrometric of Atomic Absorption. In the mercury case the spectrometric of atomic absorption with generation of cold vapors (CV-EAA) was used with sodium tetrahydroborate (NaBH4) at 0,5 % m/v in sodium hydroxide (0,1 mol L-1), with a previous digestion of the samples in regia water. The quantification was carried out using a calibration curve. The soil samples analyzed showed that the levels of mercury are high in comparison with the reference values for the Cuban soils. For the content of cadmium and lead, it is observed also high concentrations, but these are lower than those reference levels.