32
per year. Confidence limits for this estimate were obtained by
bootstrap resampling from the raw data provided by FSAS. We
drew 10,000 bootstrap samples of 200 at random from the 200
real data and performed the same set of calculations upon each
of the bootstrap sets as described above. We then took the
values bounding the central 9,500 of these bootstrap estimates
as the 95% confidence interval. The bootstrap 95% confidence
interval for the estimated number of game meals eaten per
week, year-round, is 1.49 – 1.84 meals per week. Hence, subject
to the assumptions made about the duration of the shooting
season and other issues, this survey provides reasonably
precise estimates of the rate of consumption of game meals by
this sample of high-level consumers in Scotland. If it is assumed
that a typical game meal includes 200 g of meat (EFSA 2010),
these per capita rates of consumption are equivalent to 17.1
kg per person per year (95% C.L. 15.5 – 19.2 kg) or 8.6 kg per
person per year (95% C.L. 7.7 – 9.6 kg) if a game meal contains
an average of 100 g of meat (FSA 2002). This compares with
a per capita consumption rate of gamebird meat averaged
across the whole UK population of 0.175 kg per person year,
based upon the NDNS (see above). Hence, the amount of game
meat eaten by high-level consumers is much higher, perhaps
by two orders of magnitude, than the UK average. Had those
NDNS subjects who ate gamebird meat during the 4-day diet
diary period continued to eat it at the rate reported in the diary
throughout the year, the annual per capita amount consumed
by that subset of people would have been 7.0 kg per person per
year (95% C.L. 5.7 – 8.2 kg).
Quantity of ammunition-derived
lead in food eaten by humans in
the UK
Previously it seems to have been supposed that exposure to
elevated levels of dietary lead due to ingestion of meat from
game shot with lead bullets and lead shot posed a minimal
hazard tohumanhealth. This routeof exposure is notmentioned
in theCodexAlimentarius Codeof Practiceon reducingexposure
to lead in food (Codex Alimentarius 2004). Ammunition-derived
leadmight not be eaten by consumers of game meat if nearly all
of themass of the projectiles striking the game animal remained
in large pieces, which either passed through the carcass or were
removed during food preparation or at the table. However,
X-radiographic studies show that mammals and gamebirds shot
with lead bullets and gunshot often contained lead fragments
which were small, numerous and widely dispersed in edible
tissues away from the wound canals. Results for large mammals
killed using lead bullets come from X-ray studies of red deer
Cervus elaphus (Knott et al. 2010), roe deer Capreolus capreolus
(Knott et al. 2010) and white-tailed deer Odocoileus virginianus
(Hunt et al. 2009, Grund et al.2010).They indicate the presence of
many small bullet fragments in the edible tissues of the carcass
at distances up to 24 cm fromthewound canal. Small fragments,
which form a substantial proportion of fragment mass (Knott et
al. 2010), were not removed by standard butchery practices on
deer and fragments were found in bothmincedmeat and steaks
prepared for human consumption (Hunt et al. 2009).
Substantial fragmentation of lead shot also occurs when
gamebirds and waterfowl are killed using gunshot. A UK study
(Pain et al. 2010) found small fragments on X-rays in 76% of
121 gamebirds of six species examined. In this study wild-shot
gamebirds obtained in the UK from selected supermarkets,
game dealers or game shoots were X-rayed to determine the
number of shot and shot fragments present. Most fragments
were less than about a tenth of a shot in size. The small radio-
dense particles sometimes appeared to follow the track taken by
a shotgun pellet during passage through a bird, were sometimes
clustered around bone, but sometimes appeared to be scattered
throughout the bird. It was estimated that approximately 0.3%
of the mass of lead in the gunshot considered to have struck
gamebirds in their study would need to have fragmented
into small particles to account for the concentrations of lead
subsequently found in meals cooked using the gamebird meat.
This reflects the lead remaining after all of the large fragments
visible to the naked eye had been removed.
Studies of concentrations of lead in gamemeat also indicate that
ammunition-derived lead is present in meat eaten by humans.
Dobrowolska and Melosik (2008) measured lead concentrations
in samples of muscle tissue from ten wild boar Sus scrofa and
ten red deer shot with lead bullets. Lead concentrations in
muscle tissue were elevated above the background level at up
to 30 cm from the bullet track. Butchering and food preparation
procedures on these boar and deer would require that a
substantial proportion of muscle would have to be discarded
if all tissue retained for human consumption was to have lead
concentrationwithin the limit set by the EUof 0.1mg/kg for non-
game meat (excluding offal). Lindboe et al. (2012) found that the
mean concentration of lead in random samples of ground meat
from moose Alces alces killed in Norway with lead-based bullets
was 5.6 mg/kg.
Rhys E. Green & Deborah J. Pain