We used depleted uranium munitions in Iraq. It is slightly radioactive, less than naturally occurring uranium ore. One hazard is that while very heavy, it is subject to spalling and producing dust upon impact, which can be inhaled by anyone in the immediate vicinity, which could be significantly harmful to health over time.
One would expect this is the issue.
There are many low level radioactive isotopes or whatever, that are otherwise completely harmless insofar as the radiation produced is such cannot penetrate human skin.
If it were somehow ingested, or breathed into the lungs in the form of dust, then that is a very different matter and could fairly quickly cause various cancers.
This is the objection to depleted uranium munitions, and it is certainly something that should not be denied or glossed over, because there are people who know better. If an idiot like me out here in the cheap seats is aware of this, there are a lot more people out there in important posts and positions that will not be persuaded by bullshit boilerplate from a spokeshole.