Contribution of lead poisoning to renal impairment.

The late effects of lead on kidney function and blood pressure were studied in 38 persons occupationally poisoned in the past and in 23 workers exposed to lead. Parameters evaluated in all subjects were: creatinine clearance, hippuran renal flow, blood lead, erythrocyte protoporphyrin, aminolevulinic acid dehydratase, and blood pressure. Out of 11 combined variables, four significant factors were identified by factor analysis. The results showed the presence of the delayed adverse effect of previous occupational lead poisoning on kidney function and blood pressure. This phenomenon is a complex interplay of lead poisoning in the past, overall duration of lead exposure, and age as a major confounding variable related to aging process of the kidneys.