Lead Shot Less Toxic to Environment Than Alternative Ammunition Finds German Study

As part of the study, shot made of each of the different materials were exposed to the identical conditions in water. These measurements demonstrated, that the quantity of metal ions released into the solution varies greatly. While shot made of tungsten, bismuth, and a coated lead shot released almost no metal ions into the solution, alarmingly high concentrations were measured for shot made of copper and zinc.

For the study, shot pellets of different material types were placed in water. On the one hand, it was shown that the metal ions released into the water are very different: While tungsten, bismuth and coated lead shot emitted almost no metal ions into the water solution, alarmingly high concentrations were measured for copper and zinc shot.

Picture: A. Göttlein/ TUM

The researchers found, that it was not always the declared main component of the shot which dominated ion release. Particularly striking was a sample of iron shot that released large quantities of zinc, which obviously came from a coating.

In an immobilization test for the water flea Daphnia magna standardized according to DIN, their movement behaviour is used as an indicator for their vitality. As the study showed, even small quantities of copper and zinc consistently led to very high or complete immobilization of this model organism. In contrast, shot made of pure iron, bismuth, and tungsten did not impact the mobility of the water fleas. Nor did lead shot cause a significant impact on the mobility of the water fleas as compared to the control group.

The study concludes that, if lead shot should be banned for the reason of environmental protection, the current findings indicate that a prohibition on copper and zinc for manufacturing of shot should also be called for. Because widely different conditions concerning water quality in conjunction with the correspondingly adapted organisms occur in nature, additional studies are necessary in order to provide a sound basis for making decisions concerning alternatives to lead shot.

Department of Forest Nutrition and Water Management

Citation: Fäth J, Feiner M, Beggel S, Geist J, Göttlein A: Leaching behavior and ecotoxicological effects of different game shot materials in freshwater. Knowledge & Management of Aquatic Ecosystems. (419); 24, 2018. DOI: 10.1051/kmae/2018009