Small but significant
Despite the small sample size, a new Italian scientific study looking at blood lead levels in consumers of game meat has the potential to turn ‘the lead debate’ on its head
Packed full of rhetoric, bold accusations and pre-determined science, the debate surrounding the continued use of lead ammunition has been tainted for many years. It is, therefore, pleasing to see a new scientific study that examines the accusations, and looks at the link between the consumption of game shot with lead ammunition and the level of lead in people’s blood.
Not everything in this new study is straightforward for those of us who shoot, but it does set out to answer some well-balanced questions, while acknowledging the limitations within the study and the missing gaps of information that exist.
The aim of the study, titled ‘Blood lead levels following consumption of game meat in Italy’, was to measure and compare the blood lead levels in consumers and non-consumers of game meat, taking into account other possible sources of lead exposure. A blood sample was obtained from 95 people in total, and a questionnaire was used to collect general information and data on game meat consumption, hunting, wine drinking and other possible sources of lead exposure.
The results showed that blood lead level was not influenced by age, sex, residence in an urban or rural area, consumption of game meat, tobacco smoking, or hobbies associated with potential exposure to lead.
A more complex multiple linear regression model found blood lead level having an association with hunting and wine drinking, but still not with consumption of game meat or other parameters.
In layman’s terms, the model showed that when the effects of all the recorded variables were accounted for, the activity of hunting caused the blood lead level to be approximately double that of non-hunters, and 40% higher in wine drinkers compared with non-wine drinkers.
Previous studies looking at the link between human health and lead ammunition have focused on the hypothetical level of available lead capable of entering the bloodstream from the recorded levels of lead in gamebirds. The theory being that high quantities of lead in gamebirds will end up raising the blood lead levels in high-level consumers. This hypothesis is not supported by the findings of the new research.
Instead, the intriguing question raised by this study is whether links between game consumption and blood lead levels found by previous studies were, instead, actually links between exposure to lead ammunition and its use by hunters.
The new research raises that question, but does not answer it. Its authors conclude that although the results were of interest, the small sample size restricted its importance and the relationship between hunting and blood lead level could not be linked to either inhalation of lead fumes while shooting with lead ammunition and/ or the handling of lead ammunition.
Other studies using the Italians’ methodology have shown significant differences within blood lead levels for consumers and non-consumers of wild game.
However, the influence of the other recorded variables such as hunting, wine consumption, tobacco smoking and age, have in these studies shown varying degrees of significance, leaving the definitive answer of their importance missing.
Although there were numerous failings of process and logic in the Lead Ammunition Group (LAG) report, which caused it to be rejected by the government, the conclusion from the human health risk assessment cannot be completely rejected. It stated: “The consumption of meat from wild game animals killed using lead ammunition poses risks to some high-level consumers of wild game.”
Risk, in this instance, is on the same scale as overindulging on red meat or shellfish, not eating your five-a-day, or even drinking wine (which also contains significant levels of lead). What the risk level is and where the risk is coming from remains completely unknown.
The LAG also noted that “the human health risk assessment is based mainly on calculations using measured levels of contamination with ammunition-derived lead and absolute bioavailability estimates of lead from gamebirds killed using lead shot”. Indeed, the Food Standards Agency’s advice to high game consumers comes on the back of these calculations, completed by the RSPB and WWT. But does this new research suggest that they have overestimated the impact of the lead ammunition found in gamebirds on those who eat them?
Whether the answer is yes or no, the Italian study highlights the necessity for further research into the use of lead ammunition, so the full picture can be revealed. This is research that needs to be completed before any further restrictions on the use of lead ammunition can even be considered.
The new study found that blood lead levels were not influenced by consumption of game meat
Further research is needed into the use of lead ammunition