My observations over the years have led me to believe that the lead shot issue is like many other issues--most people are going to believe what they want to believe--and look for sources that support their belief while ignoring others.
There's been a wealth of info from unbiased sources on lead impacts over the years. Lead is a toxic poison that at certain levels creates irreparable harm, there is not way to reasonably dispute that fact.
There's no way to dispute it's impact on waterfowl and species that eat waterfowl either. Loons and swans can be included there in addition to ducks and geese.
Upland game is a bit trickier perhaps, but given this is a pheasant forum, with a few exceptions perhaps I doubt that there are many of us who has not occasionally--even frequently--shot a load of shot over water--or seasonably flooded wetlands that might be dry in the fall.
One thing I don't see anyone recognizing is how much the price of quality steel shot loads has changed in comparison with the same in lead.
This ought to hit home for pheasant hunters in particular. As an example, Fiocchi golden pheasant lead loads are $15 to $18 a box nearly everywhere I have gone recently. Kent Fast Steel loads are $11 to $15.
If you look around a bit--and shoot a 12 gauge or 20 with 3" chamber--price is no longer a reason not to switch to steel.
The big game issue came up suddenly and was discovered by a guy with an admitted agenda and affiliation that clearly wasn't too keen on use of lead.
Unfortunately, as happens on occasion--despite his bias, he was right. Continued work has proven that lead bullets commonly fragment and that light coatings of copper do nothing to change that (there's some reason to believe those with a small lead core and heavy lead or other alloy nose and covering may be less of a problem). And that the fragments often fly dramatically far from the wound channel, negating any thought that a good job of tossing out damaged areas along the wound channel will eliminate the problem.
I'm not all that worried for myself or older women past child bearing age, but kids and pregnant women--well the evidence is more than a bit disconcerting.
There are some organizations with close ties to the shooting industry--NSSF for example--that are clearly advocating not for the truth but for the selfish interests of an industry that isn't ready to change yet.
This demonstration may be of interest to big game hunters with an open mind--be sure to click on the slide show and turn up the volume on your computer:
http://www.dnr.state.mn.us/hunting/lead/index.html