The Army's tungsten-based bullets were designed to be more eco-friendly, but research showing tungsten increases cancer risk pushed them to pull the plug. The problem, Danger Room points out, is that tungsten munitions are everywhere.
The Army began using tungsten in its weapons to replace depleted uranium, which is also allegedly (but notoriously) nasty stuff. Tungsten is used in missiles carried by drones, the Phalanx anti-missile gatling gun, anti-tank rounds and a lot more. What's crazy is that even as the Army stops using tungsten in training ammo, it's still looking at tungsten as a depleted uranium in other stuff.
On the other hand, it's not like bullets and other weapons, though they might be more advanced technological terrors, aren't designed to horrible things to human beings in the first place. [Danger Room, Image: longhorndave/Flickr]