Lead Bullet Fragments in Venison from Rifle-Killed Deer: Potential for Human Dietary Exposure

Abstract

Human consumers of wildlife killed with lead ammunition may be exposed to health risks associated with lead ingestion. This hypothesis is based on published studies showing elevated blood lead concentrations in subsistence hunter populations, retention of ammunition residues in the tissues of hunter-killed animals, and systemic, cognitive, and behavioral disorders associated with human lead body burdens once considered safe. Our objective was to determine the incidence and bioavailability of lead bullet fragments in hunter-killed venison, a widely-eaten food among hunters and their families. We radiographed 30 eviscerated carcasses of White-tailed Deer (Odocoileus virginianus) shot by hunters with standard lead-core, copper-jacketed bullets under normal hunting conditions. All carcasses showed metal fragments (geometric mean = 136 fragments, range = 15–409) and widespread fragment dispersion. We took each carcass to a separate meat processor and fluoroscopically scanned the resulting meat packages; fluoroscopy revealed metal fragments in the ground meat packages of 24 (80%) of the 30 deer; 32% of 234 ground meat packages contained at least one fragment. Fragments were identified as lead by ICP in 93% of 27 samples. Isotope ratios of lead in meat matched the ratios of bullets, and differed from background lead in bone. We fed fragment-containing venison to four pigs to test bioavailability; four controls received venison without fragments from the same deer. Mean blood lead concentrations in pigs peaked at 2.29 µg/dL (maximum 3.8 µg/dL) 2 days following ingestion of fragment-containing venison, significantly higher than the 0.63 µg/dL averaged by controls. We conclude that people risk exposure to bioavailable lead from bullet fragments when they eat venison from deer killed with standard lead-based rifle bullets and processed under normal procedures. At risk in the U.S. are some ten million hunters, their families, and low-income beneficiaries of venison donations.

Cadmium, Lead, and Chromium in Large Game: A Local-Scale Exposure Assessment for Hunters Consuming Meat and Liver of Wild Boar

“…Although comparisons are sometimes difficult because of differences in data manipulation, our results for lead fall within the range of values found in the surveyed literature, with the exception of the highest values reported by some investigators (Morales et al 2011;Taggart et al 2011). In those studies, lead levels in WB were most likely caused by lead dispersion into the animal body mass after bullet fragmentation (Hunt et al 2009). …”

“…Lead exposure in hunters' households may be particularly high if the animals are shot using lead bullets and contaminated tissues not carefully discarded (Hunt et al 2009;Tsuji et al 2009). In our study, this issue was not included in MCM exposure simulations because the bullet pathway area was carefully excluded during sampling.…”

Reducing Pb poisoning in birds and Pb exposure in game meat consumers: The dual benefit of effective Pb shot regulation

“…It is well recognized that Pb shot and bullets can suffer from fragmentation on impact with game animals. This can result in quite widespread contamination around wounds and increase the risk of exposure to Pb in human consumers of game meat (Hunt et al, 2009;Johansen et al, 2004;Pain et al, 2010;Scheuhammer et al, 1998). Moreover, common recipes that use acidic ingredients, like vinegar or wine, to cook game meat can further increase the transfer of Pb from ammunition to the meat and enhance the subsequent bioavailability of that Pb (Mateo et al, 2007.…”

Consumption of wild-harvested meat from New Zealand feral animals provides a unique opportunity to study the health effects of lead exposure in hunters

“…When wild game animals are killed with lead projectiles, hundreds of lead fragments are dispersed throughout the carcass and packages of processed wild game are reported to contain lead fragments (Hunt et al 2009). There is also a correlation between subsistence hunters using lead projectiles and elevated levels of lead in the blood (Tsuji et al 2008;Iqbal et al 2009;Fachehoun et al 2015).…”

“…Specifically, after a run-in period and baseline blood lead-level assessment, hunters would be given lead or lead-free bullets and asked to harvest and process their deer. Within the lead pharmacokinetic peak of 2-4 days after ingesting lead (Hunt et al 2009), hunters and their families would be asked to provide blood and urine samples for lead-level measurement and report the location where the game eaten was harvested. Since individual hunters tend to harvest game from a specific geographic area, a crossover study design would be possible, with hunters switching to the other projectile type after 1 year.…”