Cadmium concentration in the kidney cortex of occupationally exposed workers measured in vivo using X-ray fluorescence analysis

A method for in vivo X-ray fluorescence analysis of the cadmium concentration in the kidney cortex has been improved and tested in 20 selected male occupationally cadmium-exposed workers (duration of exposure 7–39 years). The concentration of cadmium in kidney cortex ranged from 47 to 317 (median 141) μg/g. The concentration of cadmium in blood was 32–160 (median 64) nmole/liter, cadmium in urine was 2.5–13 (median 5.4) nmole/mmole creatinine, and β 2-microglobulin in urine was 3.3–68 (median 14) μg/mmole creatinine. In individuals, the relationship between duration of exposure, time-integrated exposure, and cadmium level in urine on the one hand and cadmium level in the kidney on the other varied considerably. Direct in vivo analysis of the concentration of cadmium in the kidney cortex is therefore valuable as a complement to the other tests when monitoring cadmium exposure. Our method is sensitive, practically free from risk, and can be performed by routine at low costs.