Look up DU testing for your specific State. Every returning Veteran "should" be tested, yet how many are?
Unless the Veteran knows to ask for the test, they aren't likely to offer that information.
When my daughter was returning from AF, they were told that just for breathing the air in AF they would all automatically be on 10-20% disability through the VA for the DU. I don't know how long after you've been exposed to the DU that it will show up in the types of tests they do. Once she was home, there was never again mention of the disability, nor any kind of testing.