RESUMEN
Clinical, biochemical, haematological and erythrokinetic studies were performed on 63 adult males with prolonged lead exposure. Their most common symptoms and findings were abdominal pain (62%), gingival lead lines (48%), headache and/or dizziness (33%), muscle cramps (32%), anaemia (19%), and fatigue (18%). Colicky abdominal pain (27%) and gingival lead lines correlated with urinary lead excretion. Anaemia was mild, but more frequent in the subjects with the greatest urinary lead excretion. Other associated findings were: higher reticulocyte counts and more basophilic stippling of the RBCs, more sideroblasts and greater erythroid hyperplasia of the bone marrow, more reduction in 51Cr-tagged RBC survival time, smaller RBC mass, a more rapid plasma iron clearance, a greater plasma iron turnover and greater utilization of 59Fe in subjects with urinary lead excretion of greater than 100 microng/day in comparison with the remainder and normal controls. These findings suggest that minimal chronic exposure to lead causes an increased haemolysis with resulting increased production of erythrocytes.