Aminoaciduria in Japanese Workers in the Lead and Cadmium Industries

Abstract

Amino acid excretion in urine from workers in the lead and cadmium industries in Japan was measured and compared with other parameters of intoxication. Mean alpha amino nitrogen excretion by lead workers exceeded that of control individuals (p < 0.05). Whereas all lead workers had excessive urinary lead excretion and nine of 10 had elevated d-ala excretion, only two lead workers had severe aminoaciduria. Only three workers in the cadmium industry had elevated urinary amino acids, protein excretion, or both. The cadmium worker with the most severe aminoaciduria was also thought to be a carrier of cystinuria. Conclusions are that aminoaciduria is a less sensitive index of lead and cadmium intoxication than other biochemical parameters, and second, that individuals who are carriers for a genetic abnormality of renal tubular transport may have enhanced susceptibility to the adverse renal effects of heavy metals.