The importance of cadmium as a factor in calcified upper urinary tract stone disease--a prospective 7-year study.

The non-essential trace metal cadmium may cause major pathological effects on the kidneys. A group of coppersmiths who have been chronically exposed to cadmium poisoning was systematically studied over a 6-year period. The stone prevalence in the group is now just under 40% as compared with 3.5% in a general population. The blood cadmium levels have remained persistently elevated despite removal of the cadmium source. The measurement of cadmium as a means of monitoring chronic poisoning has been undertaken in terms of the prospective study in the coppersmiths and also in its relationship to other trace metals, namely serum zinc and copper. Urologists should be aware of the possibility of cadmium poisoning.