Biological Response and Subjective Symptoms in Low Level Lead Exposure

Abstract
Workers occupationally exposed to lead in the air of up to 60μg/cu m were examined for blood lead (Pb-B), urinary δ-aminolevulinic acid (ALA), erythrocyte ALA dehydrase (ALAD), hemoglobin, hematocrit, red blood cell count, and subjective symptoms. The Pb-B and ALAD showed consistent increases and decreases, respectively, corresponding with the levels of Pb exposure, while other tests revealed no association with Pb. The range of Pb exposure as expressed by Pb-B was up to 50μg/100 gm. Subjective symptoms and urinary ALA are not likely to be increased at the Pb-B level of about 50μg/100 gm and less.