As a matter of interest, I have a book on the famous rifle ranges at Bisley, in England. They state that they do not feel lead is an issue, the ranges have been in use since 1890, and there has never been any attempt to close the ranges because of lead laying around. The area is a nature preserve too. I do have a concern re waterfowl, but not upland gamebirds. (Puts flame suit on and prepares to lose yet another star.)
In the matter of steel shot for Olympic Clay target, the International Shooting Sport Federation came to the conclusion that the use of steel shot in Olympic Trap and Skeet should be prohibited due to the danger to shooters and range personnel from ricochets. Timely for the season: "don't shoot your eye out" like I nearly did 50 years ago with a steel BB bouncing back from a sheet of plywood. 177 lead pellets do not ricochet to any degree.