Craig: reasonable people, with some capacity to critically analyze information, can disagree regarding methodology, statistical analysis, interpretation and most certainly the application of the information.
Lead is a (useful) environmental toxin, and especially hazardous to children.
IMHO a dead duck, with a green vent, lead in the gizzard and an elevated lead level is adequate evidence of a problem.
Conservationists have been concerned with the issue for 120 years, and professional wildlife biologists have been publishing articles for 60 years, which I cited. And at least the wildlife biologist I met in Kansas, with degrees from Ft. Hays State, Emporia State, and K-State were mostly from rural areas, smart and fully capable of critically analyzing some of the stuff coming out of Washington. I believe ad hominem attacks on their integrity, because one doesn't like the data, is inappropriate. (See the Eagles thread)

It doesn't help to throw into a pot lead toxicity in waterfowl, lead toxicity in raptors, lead toxicity in scavengers and then mix in climate change, the efforts by some to outlaw sport hunting, shut down target ranges and outprice target shooting, lead in the water in Flint, the "Green Movement", COVID, George Soros, Greta Thunberg & environmental racism and pour out some vast conspiracy theory as to why lead shot was banned. Conspiracy theories (and faux-omniscience) are coping mechanisms, esp. for the not so smart and those with OCD, but we usually find out over time that they are detached from reality.

Since lead shot was banned, lead levels in waterfowl have fallen dramatically. I wish there was better data to confirm that fall has resulted in lower mortality - everyone keeps repeating an "estimated 64% reduction" based on a single study > 20 years ago. Unfortunately. waterfowl diseases have been increasing during that same period.
And I agree steel shot is terrible stuff for humanely harvesting game.