[The value of determining delta-aminolevulinic acid in urine (method II, East German occupational monitoring) as a screening procedure for the assessment of internal residues in occupational exposure to lead].

For the purpose of supervising workers exposed to lead the ratio of blood lead is determined several times per year. The withdrawal of blood samples from the vein necessary for this purpose as well as the comparatively high analytic expense make it essential to revise, whether it is possible to give up the analysis of blood lead at least partially in favour of other diagnostic measures less affecting the worker. Our investigation gave evidence of the fact, that the validity of a screening test for evaluating the blood lead concentration on the basis of the determination of delta-aminolaevulinic acid in urine (method II, AB-DDR; 2 nd morning urine) is insufficient.