So I’ll add a couple things about the papers that @Article 4 brought up. And just for reference, I prefer using lead ammo for hunting and would like to continue that until better options become available.My understanding is that greenlanders overall eat a lot of caribou and seal meat as well, presumably they would often be killed using lead bullets (though it seems seals are often head shots? Way out of my depth on seal hunting practices). The data seems to correlate specifically to bird shot, without any apparent spike in BLL for those who eat caribou but not birds?
They claim, "Blood lead was low (15 μg/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 μg/L (mean concentration)."
If I understand correctly though, that 128 number was one IDPA shooter and the rest of the bird eaters were a tiny fraction of his BLL. Why leave that data point in the abstract as the singular reference point for bird eating cohort without explanation or context? If I've confused this with another study please let me know. It speaks to the picture they want to paint vs what the data shows.
If I, a half retarded Idaho redneck with no stats training beyond a couple of 100-200 level undergrad courses, am noticing these issues on a quick reading of the study, how many more methodology and bias errors are there likely to be?
Lead studies often don’t address that there are multiple sources for lead in the environment. The Greenland paper discusses a population that largely lives on marine mammals which have high lead levels due to biomagnification (eating lots of smaller stuff that has trace levels of lead).
Part of the issue with not understanding sources is also cultural. Most ecotoxicologists are not hunters or shooters and do not understand the potential exposures those groups have. The IDPA example is a good one. High volume competitive shooters and range staff have just started recognizing over the last few years that lead styphenate primers put them at risk for high levels of lead contamination. The researchers likely had no idea of how to explain that outlier in their data. And high levels of lead like this would be more likely to show up in a sample of game meat eaters than a control group that is less likely to contain competitive shooters. Likewise, there may be other correlations that aren’t considered. I live in an older house built in 1955. Last year we started remodeling our kitchen cabinets and found out they had lead oxide paint on them. If I am part of either group, that lead exposure would be considered part of the random background level. Are hunters who process and eat game meat more likely to do their own home repairs?
The British paper is also an example that requires some context. Britain and Europe have a substantial game meat industry, where wild rabbits, wood pigeons, pheasants, and other game are sold whole in the market to the public. Anyone who has experience processing game shot with a shotgun knows that they have to go into every whole in a carcass to remove the hair, feathers, and shot that are in those holes. And anyone who’s hunted birds will also know that # 7 1/2 or #8 shot is not too small to find. The researchers likely took their samples from whole animals without understanding how the animals are processed by hunters prior to eating, and non-hunters who buy them may not understand how to process them either. These papers and the game meat trade in Europe are the primary reason why lead ammunition is now largely banned there for hunting. There is no similar commercial game meat trade in the US. If there was lead might already be banned.
Is lead bad for you? Undoubtedly. There is a pile of research showing that all forms of lead are detrimental to human health, but some are much worse than others. Metallic lead is the least detrimental, at least in mammalian digestive systems. Metallic lead in game meat is also a risk that we can largely mitigate through good trimming practices. If you take your game to a commercial processor, you are passing on that option to someone who likely does not understand what they need to trim, and you may be better off looking at non-lead options if you want to avoid or minimize exposure.
Thus far, this discussion is wholly about the risk to human consumers. There are other considerations that people using lead ammunition may consider to reduce environmental effects of lead. Lead in gut piles has been shown to be a significant issue in raptors and other carrion eating birds in some areas, but not to my knowledge for mammalian scavengers. This is likely due to differences in their digestive systems. In places where you can get an animal out whole, you can dispose of the offal and carcasses in places where there is less risk to avian scavengers like eagles. If you can’t get them out whole, burying or covering the carcass and gut pile with brush can reduce the chance that avian scavenger will find it. Mammalian scavengers will find it, but there isn’t any data showing high lead levels in coyotes and the like compared to avian scavengers. Obviously, using non-lead ammo is also an option.
My take is that if we want to continue to use lead, and I do, we hunters should use it carefully and try to limit unintentional exposure to people and other wildlife.