Hemorheology in occupational lead exposure

Abstract

The purpose of this investigation was to study hemorheological parameters in occupationally lead exposed men. For 15 clinically healthy lead-exposed male subjects [age 34.6 (SD 8) years] the viscous (epsilon') and elastic (epsilon") components of whole blood viscosity corrected for 45% hematocrit were measured for shear rates between 1.s-1-100.s-1 at 37 degrees C. Moreover, lead concentrations in blood and urine and the delta-aminolevulinic acid dehydrase level were determined. Fifteen unexposed age-matched men were used as referents. The mean lead concentration in the blood and urine of the lead-exposed men was 48.7 (SD 16.2) micrograms. dl-1 and 38.8 (SD 17.1) micrograms.g creatinine-1, respectively. While epsilon" was significantly increased only at low shear rates, epsilon' was elevated throughout the investigated shear range in comparison with the values of the unexposed referents. These results are characteristic of erythrocytes with enhanced rigidity. The aggregation and filtration index of erythrocytes were significantly elevated for the lead-exposed workers. A positive correlation existed between lead in blood and epsilon' or epsilon", whereas delta -aminolevulinic acid dehydrase and epsilon' or epsilon" were inversely correlated. No differences in plasma viscosity or in lipid status could be detected. Increased blood lead concentrations can be considered an additional risk factor for vascular diseases predisposing towards microvascular occlusion.