Environment

It's not. Historically lead has been used in bullets and shot because it's both cheap and very dense. You need something with mass in order to impart energy on the target. If the mass of the projectile were irrelevant everybody would just load their shotgun shells with rice or something. Obviously it doesn't work that way.

I believe the consensus (based on the downvotes) is that the poster above is trying to tacitly make some kind of insinuation that lead is "necessary" due to its density in opposition to banning it, which I lightly debunked in my other comment. Other significantly less environmentally harmful materials are available and in fact already mandated in some areas for shotgun hunting.