Occupational lead exposure and screening of glucose-6-phosphate dehydrogenase polymorphism: useful prevention or nonvoluntary discrimination?
OBJECTIVE
To discuss regulatory guidelines excluding subjects with erythrocyte glucose-6-phosphate dehydrogenase (G6PD) deficiency from lead-exposed jobs in the light of epidemiology findings on the mortality of these subjects.


METHODS
Two mortality follow-up studies were conducted. The first comprised 1979 male subjects newly identified as G6PD-deficient during a 1981 screening of the G6PD polymorphism among the general population in Sardinia, Italy. The second comprised 1080 male workers employed in maintenance and production departments of a lead smelting plant, who were divided into two subcohorts by erythrocyte G6PD phenotype.


RESULTS
As compared with the general male population, G6PD-deficient subjects had significantly fewer deaths than expected from ischemic heart disease (standardized mortality ratio (SMR) = 28; 95% CI 10-62), cerebrovascular diseases (SMR = 22; 95% CI 6-55), and liver cirrhosis (SMR = 12; 95% CI 0-66). Among lead smelters the standardized mortality rates from cardiovascular diseases and all cancers observed among the G6PD-deficient subcohort were lower than those seen among subjects with the wild-type G6PD. No death from disease of the blood and hematopoietic system was observed among G6PD-deficient subjects in these two follow-up studies.


CONCLUSIONS
These studies did not provide evidence of hypersensitivity to lead hematotoxicity among G6PD-deficient individuals at exposure levels within the current standards. Provided that workplace exposure complies with current standards, the hypothetical benefit of excluding G6PD-deficient individuals from lead-exposed jobs should be weighted against the loss of personal abilities and the economic damage in a social environment with diffuse unemployment.
Cocco
P
P
Instituto di Medicina del Lavoro, Università di Cagliari, Italy. coccop@pacs.unica.it
D000293:Adolescent; D000328:Adult; D000368:Aged; D004608:Eligibility Determination; D004651:Employment / Q000592:standards; D016021:Epidemiologic Studies; D005387:Finland; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000150:complications* / Q000401:mortality*; D006801:Humans; D006967:Hypersensitivity; D007854:Lead / Q000009:adverse effects*; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D016273:Occupational Exposure / Q000592:standards*; D016272:Occupational Health / Q000331:legislation & jurisprudence*
D007854:Lead