Statistically significant hematopoietic effects of low blood lead levels

Blood lead (Pb-b) concentrations, hematocrit (Ht), and hemoglobin (Hb) were determined in three groups of men working in different parts of a cable-producing factory. All three parameters examined, i.e., Pb-b, Ht, and Hb, in the above groups were found to be within "normal" limits. However, within each group of men studied, there was a statistically significant negative correlation between Pb-b concentrations and Ht and Hb values. This finding indicates that any increase in Pb-b concentration, even within the "normal" values, may result in a decrease of hematocrit and hemoglobin values of the same subjects.