Can salivary lead be used for biological monitoring of lead exposed individuals?

Abstract

Measurement of blood lead (BPb) is the usual method for biomonitoring of persons exposed to inorganic lead. To explore the use of salivary lead (SPb) as an alternative. BPb and SPb levels were measured in a group of 82 lead exposed adults. The mean BPb of the workers was 26.6 microg/dl (SD 8.6, range 10-48) and the mean SPb level 0.77 microg/dl, or 3% of the BPb level. As the SPb distribution was skewed, logarithmic transformation was performed to normalise the distribution. A bivariate scattergram of BPb and logSPb (r = 0.41, p = 0.00) had a line of best fit expressed as BPb = 29.7 + 8.95logSPb. The relation of logSPb and BPb was stronger among non-smokers (r = 0.42) compared to smokers (r = 0.3); and among those without a medical condition (r = 0.44). Multiple linear regression analysis (fitting smoking and medical condition into the model) yielded an R of 0.54, and an adjusted R(2) of 0.26. The study findings do not support the use of SPb for biomonitoring at BPb levels ranging from 10 to 50 microg/dl.