I'm not a scientist but I have experience reading technological and scientific papers. That being said;
Your first link was a valid study result but it really didn't prove that animals taken with bullets were a potential source of health threatening lead poisoning. There are several points that I think make the study questionable.
1. The study says that all weapons used to take the animals were 7mm Mag rifles using 150gr cup and core style ammunition. Toward the end of the paper they mention that some of the meat used to feed the pigs with had bird shot in it. Just how accurate was their data when they claim that only bullets were used and yet they offhandedly mention that bird shot was in the meat.
2. Their experimental method was to take game killed and field dressed by average hunters to a game processor who then processed the meat and then they fed the contaminated meat (identified by radiographic methods) to pigs. They then tested the lead levels in the pigs for 8 days after being fed the meat.
A. They didn't verify that the meat that they turned in was the same meat that they received from the processors - could that explain why they found shotgun pellets in some of the meat that was, supposedly, all taken with 7mm Mag rifles.
B. They fed the pigs almost 3 pounds of meat in one 24 hour day. Even accounting for the weight differences between the pigs and the average person, that would mean that we would have to eat around 1 1/2 lbs of contaminated meat in one day. Who eats 1 1/2 lbs of meat in a day. And even if you do eat that much meat in a day, how much would actually be contaminated with lead from a kill, I suspect not as much as what those pigs were fed.
C. Their final conclusion was that the pigs that ate the contaminated meat showed lead blood levels of as high as 3.8 micro-gram/dL for one pig with an average of around 2.2 micro-gram/dL . The report states that the CDC says that lead blood levels in children becomes dangerous at 10 micro-gram/dL . What's more, the pigs only showed the higher levels for the about 3 days after ingesting the meat. So, in order to reach the CDC level that is dangerous for a child, the child would have to eat an average of 5 1/2 lbs of meat in a 24 hour period every three days in order to sustain a health threatening blood lead level. For an adult we would probably have to eat much more. And we would have to ensure that all of that meat was contaminated with lead. I find that pretty hard to imagine.
I couldn't get to your second link, I don't know if it is dead or if my security software prevented me from getting to it but I couldn't check it out.
Your third link required me to pay for the report and I'm not about to do that so I couldn't read it but the summary that was available for free states that the report concludes that
That's not really anything that seems to be news to anybody that hunts game nor does it seem to conclude that eating game could cause lead poisoning.
Your fourth link doesn't really prove anything, it's just a summary of other papers and studies, it's simply a reference resource for the The Minnesota Department of Natural Resources (MDNR). Quoting from other studies doesn't prove anything without including the process and conclusions.
