Exposure to subcutaneously implanted uranium dioxide impairs bone formation

The introduction of uranium particles into subcutaneous tissue is a risk that affects workers engaged in the extraction, purification, and manufacture of uranium, as well as soldiers who are wounded with uranium shrapnel. The authors evaluated the effect of an internal source of an insoluble form of uranium on bone. Uranium dioxide powder (0.125 gm/kg body weight) was implanted subcutaneously in rats. After 30 days, animals exposed to uranium weighed less than controls. Bone formation activity in endochondral ossification and bone growth were also lower in the experimental animals, as evidenced by histomorphometric and morphometric methods. This is the first study to report bone damage resulting from continuous, nonlethal exposure to an insoluble compound of uranium dioxide over a period of 30 days.