Workers, who had been exposed to cadmium oxide fume, i.e., engaged in welding work with cadmium containing silver solder in an automobile parts manufacturing factory, were examined in 1975. Twenty two male welders were 22 to 55 years old and exposed to cadmium for periods ranging from 7 months to 23 years.
Excreted urinary cadmium levels varied from 5.7 μg to 184.9 μg per day, and these values were useful indices of most recent exposures in workshop environments. The examinees were divided into three groups according to excreted urinary cadmium levels: five of them in high, eleven in middle, and six in low group, respectively. Workers in high-excretion group complained of considerable subjective symptoms and their urinary protein showed a remarkable increase, compared to middle- and low-excretion groups, and the electrophoretic pattern of urinary proteins showed preponderance of globulins.
Urinary calcium and β₂-microglobulin in the high-excretion group showed a remarkable increase. In all examinees, urinary phosphate, calcium, and β₂-microglobulin were significantly correlated with urinary excreted cadmium.
Furthermore, in the high-excretion group showed a considerable increase of serum creatinine values and reduction of creatinine clearance, and percent tubular reabsorption of phosphate, calcium and β₂-microglobulin decreased. In all examinees, creatinine clearance and percent tubular reabsorption of both phosphate and calcium were significantly negatively correlated with urinary cadmium excretion.
Therefore, five high-excretion workers showed evidence of chronic renal tubular dysfunction and one of these was particularly recoginized as having remarkable renal damage.
The possibility to affirm the effects of exposure to cadmium was suggested on hematological findings related to anemia. Liver function abnormalities were not recoginized. A slight reduction of the respiratory function was found in one worker of the high-excretion group, but radiological examination of chest showed no abnormalities in all examinees.