A PILOT-STUDY OF LEAD AND CADMIUM EXPOSURE IN YOUNG-CHILDREN IN STOCKHOLM, SWEDEN - METHODOLOGICAL CONSIDERATIONS USING CAPILLARY BLOOD MICROSAMPLING

A capillary blood microsampling technique was tested among urban young children in Stockholm. Blood lead (BPb) and hemoglobin (Hb) concentra tions were determined in capillary blood obtained by fingerstick from 41 children, 13-20 months old, and the accompanying parent. The qualit y control included control for lead (Pb) and cadmium (Cd) contaminatio n of material and equipment used for blood sampling, washing procedure s for the hands and fingers to be punctured, comparisons of Pb and Cd concentrations in blood obtained by finger-stick and by brachial vein puncture from the same individuals, analysis of external quality contr ol samples for Pb and Cd in blood together with the collected samples, and evaluation of the analytical performance using linear regression analysis. The results showed that blood sampling material may contamin ate the blood samples with amounts of Pb and Cd that would seriously i nfluence the monitoring results in the low concentration range (< 100 mug Pb/L and < 1 mug Cd/L). However, it is possible to obtain reliable BPb concentrations (> 10 mug Pb/L), but not BCd concentrations (< 1 m ug Cd/L), with the capillary blood microsampling technique tested prov ided that a strict quality control is applied. The sampling procedure tested was well accepted by the children and their parents. The childr en's median BPb concentration (27 mug/L; range 9-73 mug/L) was similar to the median BPb concentration of their parents (27 mug/L; range 7-7 4 mug/L). However, the correlation between child and parent BPb concen trations was poor (R2 = 0.20), which may indicate different source s t o Pb exposure in children and parents.