Lead from hunting ammunition is a health hazard for wildlife, ecosystems and humans. Legislation and other means of regulation have been introduced in some countries. Hunting organisations are involved in discussions about the problem, but why is progress slow and how viable are the alternatives?
The toxicity of lead has been documented over millennia. Lead is not required by any living organisms or process. The mechanisms of the toxicity arise as the body replaces calcium, iron or other metals with lead causing malfunctions in inter alia the central nervous system. Action thresholds for blood lead in humans have decreased from 60 to 10 μg/dl over the last 50 years as knowledge of the effects of lead has increased. Recent research from the UK and USA has documented effects on cognitive function, educational attainment and IQ in children at levels well below the current action threshold.
The risk of the poisonous impact of lead ammunition (shot and bullets) spread through hunting has been well-known for over a century. When hunting ammunition is fired the ballistic material will either be deposited in the target or in the natural environment (the flow of ammunition materials can be charted as in Figure 1). Spent ammunition fragments in the internal organs of shot big game animals or in carcasses of wounded animals may expose scavengers and/or the ecosystem directly to lead. Ammunition material deposited in the natural ecosystem may be ingested by macro or micro fauna, by vegetation or stay biologically inactive. Ingestion of a few (<5) lead pellets is lethal to a medium size duck. One meal on a lead infected carcass may be fatal for a bird of prey. Material deposited in killed and bagged game may be removed during butchering or stay in the game meat/venison and, if toxic, be a possible source of contamination of the consumer. A milestone in the documentation of implications for wildlife and humans of the ingestion of lead from spent ammunition is the Proceedings from the so-called Boise-conference, May 2008 (Richard T. Watson, Mark Fuller, Mark Pokras and Grainger Hunt (eds.): Ingestion of Lead from Spent Ammunition: Implications for Wildlife and Humans; see http://www.peregrinefund.org/Lead_conference/2008PbConf_Proceedings.htm).
The lead poisoning problem can be regarded from two perspectives: acute intoxication causing immediate clinical symptoms with a high mortality risk and the longer term chronic effects mainly demonstrated in humans. The impact of the acute intoxication has been demonstrated widely in waterbirds. The background for the phasing out of lead shot for hunting in Denmark in the 1990s was a general conclusion that lead intoxication caused an extra annual mortality of 2% of common species of dabbling duck (Anas ssp.). Ingestion of lead shot has been demonstrated for many other wildlife taxons. Recent research concludes that ingestion of lead from hunting ammunition is the most important mortality factor in German populations of White-tailed Sea Eagle (Haliaeetus albicilla).
For half a century governments and stakeholders in North America and Europe have been aware of the problem and during the last couple of decades some regulation has been introduced. No countries have banned lead ammunition completely. A few countries, including Norway, The Netherlands and Denmark, have banned lead shot for any type of hunting of any species in any ecosystem. In most countries with legislation regulation is limited to wetlands, while in others there is only a voluntary program. The general picture is that there is very limited progress. Except a few minor projects, there have so far been no strategies to challenge the problem of lead being exposed to ecosystems, wildlife and humans from rifle ammunition. No regulation for bullets has yet been introduced, but there are different non-lead bullet types, mostly copper bullets, available.
There are several reasons why the process is so slow. Most are connected to political and commercial interests in sustaining lead as an ammunition material. Hunters are often claimed to be against the phase-out of lead ammunition. Hence, politicians tend to take a short-term and popular pro-lead standpoint very often orchestrated by the powerful national and multinational companies having a heavy commercial interest in sustaining a high volume of lead ammunition consumption. It is often claimed, that there are no valid alternatives to lead ammunition. It is simple to prove the opposite. For 16 years now, Denmark has had a total ban on lead shot – be that for hunting or sport shooting. During this period, hunting has continued with no evidence of adverse effects on hunters and the industry. Alternative shot materials, mostly steel and bismuth, have been developed and fulfill all the needs of hunters to pursue their sport and activities. Steel shot are available at prices comparable with lead shot, though training ammunition with steel tends to be slightly cheaper that equivalent lead cartridges. Bismuth and other more sophisticated products are significantly more costly than both lead and steel shot. The process with rifle ammunition is less advanced, but a variety of lead free bullets is available, and there are strong indications that new types to match any requirement will be developed if there is a demand from hunters.
So, in a nutshell: The problem is there and is well documented. The solutions are there and only need the concern, engagement and demand of hunters and the response of manufacturers. Society is getting rid of lead: witness the disappearance of lead from petrol/gasoline. In the long term hunting based on lead ammunition cannot be regarded as a sustainable activity. Any individual being really and whole-heartedly engaged in sustaining hunting in a modern society should support the full phase-out of lead in hunting ammunition. The sooner the better.
Niels Kanstrup, Danish Academy of Hunting
Figure 1. Flowchart of ballistic material from shot and bullets. Credit: Niels Kanstrup.