Erythrocyte-Zn-protoporphyrin as an indicator of lead exposure.

Measurement of erythrocte-Zn-protoporphyrin with a haematofluorimeter on blood samples from eighty-four lead-exposed individuals has been compared with a fluorimetric determination of the extracted porphyrins. The results agreed well, and the interference from bilirubin and unchelated protoporphyrin was low. An exponential increase in erythrocyte protoporphyrin and a linear decrease in blood haemoglobin with increased blood lead was found in seventy-nine males with occupational lead exposure. The haematofluorimeter is recommended as a useful tool in screening for lead poisoning.