The primary driving factor in banning lead bullets on fed public lands is to protect the animals, not hunters and people eating them, which of course should be a concern as well.
By now it has been well demonstrated through "science" that lead is bad for people and animals, and animals that eat lead, waterfowl, scavengers, predators, etc. often get sick and die. Seeing as how the underlying purpose of National Wildlife Refuge system is to conserve wildlife and their habitat, trying to implement measures to keep them from being poisoned seems pretty reasonable to me.
A few examples of this "science" that keeps being referenced:
"One of the greatest threats to condors and a major factor demanding such intensive ongoing management is lead poisoning (
7,
9,
10). Evidence of elevated lead exposure in California condors began to emerge in the mid-1970s (
11), and lead poisoning may have been a factor for their near-extinction in the 1980s (
7). As a result, lead exposures are monitored by field crews by semiannual blood measurements for the majority of free-flying condors within California."
www.wildlifecenter.org
Predatory and scavenging birds are at risk of lead exposure when they feed on animals injured or killed by lead ammunition. While lead ammunition has been banned from waterfowl hunting in North America for almost two decades, lead ammunition is still ...
www.ncbi.nlm.nih.gov
Top predators and scavengers are vulnerable to pollutants, particularly those accumulated along the food chain. Lead accumulation can induce severe disorders and alter survival both in mammals (including humans) and in birds. A potential source of ...
www.ncbi.nlm.nih.gov
For those crying deep state anti-hunting conspiracy and claiming that this is a slippery slope issue, it isn't. It is a very simple, very minimally invasive step to keep some critters from getting poisoned. Plain and simple.