The Biden administration will for the first time send controversial armor-piercing munitions containing depleted uranium to Ukraine, according to a document seen by Reuters and separately confirmed by two U.S. officials.
Depleted Uranium has a half-life of ~4.5 billion years making it fairly safe to be around.
The real issue is that Uranium is a heavy metal but that's kind of a moot point since the alternatives are also heavy metals. The US isn't the first to donate DU round's either, The British Defense Ministry already confirmed that they would provide these rounds back in March, 2023.
It's also better to use fewer of the more effective rounds than needing to use more of the less effective alternatives in terms of spreading heavy metal around. They're only controversial because "radiation scary", and not because they're a heavy metal.