47
Box plot details: the horizontal lines indicate the median blood
lead concentration; the box indicates the interquartile range (IQR);
the vertical bars represent observations within 1.5-times the IQR;
and the circles indicate observations more than 1.5 times the IQR
away from the box, considered outliers. The dashed horizontal line
indicates the BMDL10 of 15µg/l for increased prevalence of chronic
kidney disease and the solid horizontal line indicates the BMDL01
for increased systolic blood pressure. FromVKM (2013), adapted
from results inMeltzer et al. (2013).
Figure 2: Proportion of participants with blood lead above BMDLs
DISCUSSION
The results indicate that hunting practices such as use of lead-
based ammunition, self-assembly of lead-containing bullets
and use of lead-contaminated meat for mincing to a large
extent determine human exposure to lead from cervid game
consumption.
Lead exposure from cervid meat can be seen as additional
to exposure from other foods, of which the main food groups
contributing in the general population are grains and grain
products, milk and other dairy products, non-alcoholic
beverages and vegetables (EFSA 2012). According to the most
recent (2012) representative national dietary survey in Norway,
mean game (including cervid) meat consumption was low,
at approximately 5-7 meals per year (VKM 2013). However, in
several surveys in Norway, a large proportion (40 to 70%) of the
participants consumed cervid meat at least once a month or
more often (Birgisdottir et al. 2013, VKM 2013).
The mean or median concentrations of lead in blood in various
Norwegian studies varied from 11 to 27 μg/l, which is in the
same range as studies in most European countries from the
last 10 years (Birgisdottir et al. 2013, VKM 2013). Blood lead
concentrations were lower in pregnant women than in other
adult population groups in Norway (VKM 2013). No information
on blood lead levels in Norwegian children is available (VKM
2013). Recent data show that the geometric mean lead level in
children of Swedish hunters was 11.7 µg/l (Forsell et al. 2014).
Associations between game meat consumption and blood
lead concentration have been investigated in four population
studies in Norway that were conducted prior to the Norwegian
Game and Lead study (Birgisdottir et al. 2013, VKM 2013).
In the three studies performed in the years 2003-2005, a
significant association between game meat consumption
and higher blood lead concentration was only seen in the
subgroup of male participants in one of the studies (the
Norwegian Fish and Game study). Furthermore, associations
have been observed in two recent Swedish studies (Bjermo
et al. 2013, Forsell et al. 2014) and a study from North Dakota,
USA (Iqbal et al. 2009). None of the Norwegian studies could
fully investigate the potential association between small game
consumption and blood lead levels, because of infrequent
consumption of small game among the participants. However,
such associations have been observed in two studies in
Greenland (Bjerregaard et al. 2004, Johansen et al. 2006). It is
notable that lead concentrations in small game species, such
as gamebirds, tend to be higher than in larger game, like deer
(Pain et al. 2010) and therefore the relationship between blood
lead and game consumption is logically likely to be present
in frequent consumers of small game as well. Results from
studies on associations between game meat consumption and
blood lead concentration are summarised in Table 2.
Consumption of game and human blood lead levels: Norwegian experience