[Biological and clinical studies in occupational exposure to copper and cadmium dust]

The present study was carried out on 76 industrial workers divided in four working sections and exposed to cadmium and copper fumes and/or dust for periods ranging from 2 to 32 years. There were no signs of chronic copper poisoning associated with long term industrial exposure. In all cases indeed, normal blood copper level (near 15,5 mumol/l) and normal urine copper level (53 mumol/mol creat) were found. Moreover, in the plasma, the copper/ceruloplasmin ratio was approximately 8, with both normal values in micromoles. The great elimination of copper in feces assured probably the copper homeostasis. On the contrary, particularly near the furnace, the atmospheric cadmium level was to be considered; 9 out of 11 furnacemen who worked during more than 5 years showed neither respiratory or hepatic failure nor bone mineral metabolism disturbances, in spite of urine cadmium level greater than 10 mumol/mol creat, "early warning" for renal damage. There was no significant correlation between urine and blood cadmium levels when the latter was greater than 4,5 micrograms/l (40,2 nmol/l). The high beta 2 microglobulin level for 66 p. cent of furnacemen, was the indicator of tubular damage. Therefore the urine cadmium in combination with beta 2m should be determined to detect early effects of cadmium in exposed workers.