Possible oral lead intake via contaminated facial skin.

Thirty-six workers exposed to low or moderate levels of lead at low temperature refining processes were surveyed to examine the route of lead intake. Blood lead level (BPb), delta-aminolevulinic acid in urine, lead in facial skin wipes (Face-Pb) and lead in fingernails (Nail-Pb) were measured and their personal hygienic behavior was surveyed by a questionnaire. BPb showed a significant correlation with Face-Pb and Nail-Pb (r = 0.730 and r = 0.590, respectively). Multiple regression analysis extracted the factors of smoking at the workplace, face-Pb and nail-Pb as significantly related to BPb level. Electron-microscopic observation revealed that the majority of dust particles collected from worker's faces were larger than respirable size. Lead ingestion from contaminated face skin and fingers may contribute to elevations in the BPb level among workers.