Lead levels in saliva and in blood

The relation between salivary and whole-blood Pb levels was examined in 266 male adults, 196 of whom were Pb-exposed workers. The coefficient of correlation r between salivary and blood Pb levels was .72 (p less than 0.01); the correlation was improved when salivary Pb concentrations were plotted on a logarithmic scale. The results show that the salivary Pb concentration increased very rapidly, in a more or less exponential fashion, after blood Pb levels exceeded 500 micrograms/l. Techniques of saliva collection and Pb determination by flameless atomic absorption spectrophotometry are described. The validity of using salivary Pb as a screening test is evaluated.