Limites de aplicabilidade da determinação do ácido delta-aminolevulínico urinário como teste screening na avaliação da intoxicação profissional pelo chumbo

Abstract

The relationship between concentrations of ALA-U and Pb-S for two groups of workers is reported. The first group consisted of workers from a telephone company, and the second, of workers from battery factories with average Pb-S equivalent to 17.3 (g/dl (6.2-39.4) and 61.5 (g/dl (41.1-91.0), respectively. The aim of this study was to evaluate the utilization of ALA-U levels as a screening test for different levels of lead in blood by means of High Performance Liquid Chromatography (HPLC) and of spectrophotometry. A significant correlation was found between measured ALA and levels of blood lead (R = 0.739 - first group; R = 0.902 - second group; p < 0.001). The validity of ALA-U test to evaluate different levels of lead in blood was also studied. By using ALA levels of 3mg/g creatinine as a threshold to detect levels of lead in blood equal to or higher than 20 (g/dl, the test results, for the workers in the first group, showed sensibility of 92% and specificity of 90%. In both groups, the false positives as well the false negatives were lower than 10% which was enough to validate the test.