Male painters of ceramic works were examined for parameters of biochemical lead poisoning such as erythrocyte ALAD, free erythrocyte protoporphyrin (FEP), ALA and coproporphyrin (CP) in urine as well as parameters of lead absorption such as lead concentration in blood and urine (PbB & PbU) in order to estimate the usefulness of those biochemical tests for occupatonal lead exposures. Under the lead exposure level of these painters (PbB 5-50 μg/dl, PbU 10-200 μg/l), log ALAD and log FEP showed good linear correlations with PbB, while ALAU and CPU showed significant but lesser correlations with it. The log ALAD showed a good linear correlation with log PbU, log FEP, and ALAU fairly good ones, CPU a significant but lesser correlation with it. ALAD and FEP were equally the most sensitive tests for increasing PbB of PbU. ALAU was the next most sensitive test and CPU was the least sensitive. From the view point of sensitiveness and obvious meaning as a test for lead poisoning, FEP is the most desirable test for occupational lead exposures.
