Paulsen et al. 2015 - Lead-free rifle bullets in game meat and pork

Paulsen and colleagues ran a pilot study on metal release from “lead-free” rifle bullets in hunted roe deer, hunted wild boar, and pork shoulders experimentally shot post-mortem in an Austrian abattoir. 108 90-g meat portions were X-rayed for radiodense fragments, then subjected to simulated gastric and duodenal digestion, and the digested (bioaccessible) and undigested (residue) fractions were analysed separately for seven metals (Al, Cr, Cu, Fe, Ni, Pb, Zn) by ICP-OES. The paper’s headline finding is that even in the small minority of portions with high metal content from embedded bullet fragments, the bioaccessible metal fraction stayed at the same low level as in controls — most metal stayed in the undigested residue and would be excreted via feces.

Key numbers

• 108 total 90-g meat portions: 59 from 6 roe deer, 25 from 2 wild boar, 24 from 3 pork shoulders (Table 1).
• 30/108 portions (28%) contained radiodense particles on X-ray; only 3/108 (2.8%) showed high metal content indicative of embedded bullet fragments (results section, p. 130).
• Median total metal contents across portions (digested + undigested + simulant, expressed in mg/kg) were comparable to reference values from Sager (2005b) and the McCance & Widdowson supplement (Chan et al. 1996), even in samples with radiodense particles.
• Table 5 high-content portions (µg metal per 90 g portion; dissolved/undigested ratio):
  • Roe deer with XRG bullet: Al 60/68614 (aluminum tip)
  • Wild boar with XRG bullet: Cu 32/3236 (copper body)
  • Pork with BY bullet: Cu 22/5004, Pb 15/234 (body of bullet)
• Pork pilot arm (n=3 experimentally shot shoulders) showed the only notable Pb signal: median digested Pb 15 µg/90 g portion (max 28) versus <1 µg in pork controls (Table 4); even there, the dissolved fraction was ~6% of the 234 µg residue maximum.
• No statistical analysis was conducted owing to the small sample set; the authors classify the work as preliminary.

Methods (brief)

Bullet types studied: XLC (Barnes Bullets, USA, loaded by Sellier & Bellot, CZ), XRG (Exergy, Sellier & Bellot, CZ), and BY (Bionic Yellow, RUAG Ammotech, DE) — all 0.308 inch Winchester calibre, all marketed as lead-free or low-fragmentation. Roe deer (n=6) and wild boar (n=2) were hunted at 25–40 m. Three pork shoulders (90–95 kg carcass weight, 24 h post-mortem) were suspended from a rack and shot twice each from 40 m to simulate carcass impacts under controlled conditions. Carcasses and shoulders were X-rayed (per Irschik et al. 2013) to locate radiodense fragments, butcher-trimmed to remove lacerated tissue, portioned to 90 g vacuum packs, and stored 7 days at 0–2 °C. All portions containing radiodense particles plus one “blank” portion per animal/shoulder were boiled to 72 °C internal temperature, minced, and subjected to simulated gastric (pH 3, 2.5 h, 37 °C) and duodenal (pH 6.5, 2 h, 37 °C) digestion exactly per Mateo et al. (2011), scaled up. The slurry was centrifuged at 2000 g for 10 min; digested liquid and undigested residue were digested in HNO3 + H2O2 and analyzed by ICP-OES (Perkin-Elmer Optima 3000 XL) per a protocol validated by Sager (2005a). Blanks were subtracted; results reported as µg per 90 g portion.

Implications

Certification: This is a preliminary mechanistic study of bullet-fragment metal release, not a population occurrence survey. Treat it as bioaccessibility context for game-meat threshold work — specifically as evidence that simple total-metal measurements in inhomogeneously contaminated meat (the bullet-fragment scenario) may overstate the metal actually absorbed by consumers. Do not use as a marginal distribution input for game-meat or pork rows.

Courses: Useful for explaining why trimming around wound channels matters, why “lead-free” bullets are not always metal-free (the XRG aluminum tip and Cu body, the BY copper body release substantial Al and Cu into the residue fraction), and why bioaccessibility differs from total content in fragment-contaminated tissue.

App: The paper supports a nuanced message about hunted game — bullet-fragment contamination is highly localized within a carcass (28% of portions show radiodense particles; only 2.8% show high metal content), and even when high metal contents are present they tend to remain in the undigested residue rather than the bioaccessible fraction.

Wiki pages this source may touch

• Game meats (venison, bison, rabbit)
• Pork
• Meat and poultry
• Lead
• Copper
• Aluminum

Verification notes

The pork arm of this study is an experimental shooting design, not a market survey: shoulders were obtained from a slaughterhouse and shot post-mortem under controlled conditions. The pork controls (n=6) are legitimate baseline occurrence data, but the BY-treatment portions (n=3) are experimentally contaminated and should not be aggregated into market-pork occurrence distributions. Pork-product routing on this page is for bullet-fragment bioaccessibility context, not for retail-pork occurrence.

The bullet brands (XLC, XRG, BY) and their manufacturers appear in the Methods section as experimental treatment identifiers, comparable to instrument vendor naming, because the paper’s scientific question is bullet-type-dependent. They are not brands of food product and naming them does not introduce Part 12 brand-firewall risk for downstream consumer-facing pages.

Page history

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