Depleted uranium has supposedly had horrifying effects in the Gulf War. Let's crunch a few numbers. Kuwait has an area of 17,881 square miles. If we assume the war zone was Kuwait and a similar area in Iraq and if we assume that the ground in the area has an average amount of natural radioactivity, (4 ppm of uranium) then the top inch of the war zone has over 20,000 tons of natural uranium — far more than was used as ammunition.
Radioactivity might not be that dangerous. People in the Rocky Mountain States (“where the scenery's attractive and the air is radioactive” — Professor Tom Lehrer) have low cancer mortality rates. There is also no evidence of multi-generation damage at Hiroshima.
Uranium-238 is not very radioactive anyway. It is more dangerous because of chemical poisoning than radiation poisoning. (It's the second least radioactive actinide, just behind thorium-232.) If we didn't use U-238, we would have traditionally used lead — another chemical poison.