Response of free erythrocyte porphyrin and urinary delta-aminolevulinic acid in men and women moderately exposed to lead.

Abstract

The responses of various biological parameters of the haem biosynthesis pathway in a group of adult male and female workers moderately exposed to inorganic lead have been compared. The identical range of blood lead levels in both groups indicates a similar degree of exposure. Women, however, exhibit a larger increase in free erythrocyte porphyrin (FEP) and in urinary δ-aminolevulinic acid (ALA-U) than men. The earlier response in women is probably not due to a relative degree of anaemia (menstrual blood loss) as compared to men, since there is no significant correlation between haemoglobin (Hb) and FEP or ALA-U, and consequently standardization for the same Hb-content does not modify the independent effect of lead on the FEP and ALA-U responses. A greater susceptibility to Pb of the haem biosynthesis pathway in women has therefore been confirmed by the results of the present epidemiological survey among workers of both sexes. A preliminary and limited survey on children (11 to 12 years old) of schools situated at less than 1 km from a Pb-processing plant revealed increased FEP and blood lead concentrations and demonstrated that like women children exhibit an earlier biological response to Pb-B than adult men.