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list of larger array of lead-free rifle calibres and bullet weights
that were readily available to US consumers, and potentially, if
demand warranted, to UK hunters.
The principal lead exposure and toxicity concern with lead-
core ammunition is that the lead core would disintegrate
on entering the animal and spread fragments into adjacent
organs and tissues. This concern is associated, especially, with
unbonded lead core bullets, in which the lead is not fused with
the copper outer jacket. The many small fragments of lead in
a shot animal then pose a toxic risk when either passed into
the edible meat of human food (Pain et al. 2010), or become
ingested by scavengers that eat the discarded remains of shot
animals (Watson et al. 2009, Haig et al. 2014). The effectiveness
and lethality of lead-free rifle bullets made of copper or gilding
metal have been demonstrated by field shooting on UK species
of deer (Knott et al. 2009) and on German species of deer and
wild boar (Sus scrofa) by Spicher (2008). These results have been
supported by the experimental shooting of euthanised sheep
and wild white-tailed deer Odocoileus virginianus by Grund
et al. (2010) at distances of 80-175 m. Further evidence of the
effectiveness of lead-free rifle bullets is provided by detailed,
controlled, ballistic experiments of Trinogga et al. (2013) and
Gremse et al. (2014). Both studies concluded that lead-free
bullets were equally as effective as lead-core counterparts in
expanding, creating destructive wound channels, and retaining
their initial mass after penetration. It is possible that some
tiny copper bullet fragments could be ingested by scavengers
(e.g. golden eagles Aquila chrysaetos) and humans. However,
Franson et al. (2013) reported that American kestrels Falco
sparverius experimentally-dosed with copper pellets did not
exhibit any signs of toxicity.
Jurisdictions with lead-free
ammunition hunting regulations
Regulation of lead ammunition began with controls over
hunting in wetlands because that was where the most obvious
signs of lead exposure in wildlife existed, from as long ago as
the middle of the last century (Bellrose 1959). Lead poisoning in
terrestrial birds, especially gamebirds, and in raptors has been
reported for similarly long periods (Calvert 1876, Mulhern et al.
1970). The USA and Norway were the earliest nations to enact
laws requiring use of lead-free shot over wetlands in 1991, and
since that time, an increasing number of countries have enacted
similar restrictions to the same conservation end (Avery and
Watson 2009, Mateo 2009).
The African-Eurasian Migratory Waterbirds Agreement (AEWA)
original Annex text when it came into force in 1999 (4.1.4) read
that “Parties shall endeavour to phase out the use of lead shot
for hunting in wetlands by the year 2000” and as a contribution
to delivering the Aichi 2020 Biodiversity targets, it was agreed
in 2012 that AEWA Parties should not only phase out the use
of lead shot in wetlands but also evaluate the effectiveness of
national measures already taken to this end, and understand
and address barriers to implementation where measures are
not effective (AEWA 2012; see also Stroud 2015, for policy
commitments). Increased awareness of the extent and severity
of lead exposure from spent ammunition to a range of wild bird
taxa (Painet al. 2009,Watson et al. 2009) has led to the realisation
that greater regulation is also needed for hunting/shooting over
terrestrial habitats. Most recently, published studies revealing
elevated levels of lead in shot game used as human food have
raised concerns about the need for new regulations to address
this source of exposure (Guitartet al. 2002, Pain et al. 2010, Green
and Pain 2012).
Internationally, the regulation of lead ammunition use over
terrestrial habitats is very limited, whether in rifles or shotguns.
California is the only state/country to have passed legislation
requiring the use of lead-free rifle ammunition for hunting.
The Ridley-Tree Condor Preservation Act of 2007 applies to
hunting in the range of this species, and was passed to reduce
lead exposure in condors to fragments of lead from spent
ammunition. California has since passed law AB711 in 2013 that
will require all hunting with shotgun or rifle to be conducted
state-wide with lead-free ammunition by 2019, so extending
the power of the Ridley-Tree Act. The passage of these laws is
predicated on the known effectiveness of lead substitutes and
their growing availability as makers increase their production
towards 2019. The state of South Dakota also passed into law
(1998) the requirement that all upland game hunting with
shotguns use lead-free ammunition on both private and state-
owned lands.
The most progressive legislation is provided by Denmark
which, since 1996 has required lead-free ammunition to be
used for all shotgun hunting and non-Olympic target shooting.
Enforcement of the law, and thus hunter compliance, is
enhanced by prohibiting the import, possession, and use of lead
shot cartridges (Kanstrup 2006). Denmark still has to act on the
use of lead-core rifle ammunition. The Netherlands also requires
Vernon G. Thomas