Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation

Abstract

Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg⁻¹, ranging up to 110 mg kg⁻¹. The mean lead concentration was 5.6 mg kg⁻¹, i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg⁻¹ bw), a single serving would give a lead intake of 11 µg kg⁻¹ bw on average, with maximum of 220 µg kg⁻¹ bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 µg kg⁻¹ bw (27 µg kg⁻¹ bw) for one serving per week and 25 µg kg⁻¹ bw (45 µg kg⁻¹ bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 µg kg⁻¹ bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as those found in the present study may imply an increased risk for adverse health effects. Children and women of child-bearing age are of special concern due to the neurodevelopmental effects of lead.

Keywords:

• metals analysis – AAS
• exposure modelling
• lead
• meat

Acknowledgements

This study was funded by The Norwegian School of Veterinary Science and the Norwegian Veterinary Institute. The authors thank all those who submitted meat samples to the study. Rolf Bjerke Larssen is appreciated for statistical advice. Thor A. Waaler and Kjersti Løvberg are appreciated for conducting the chemical analysis.