The Toxic Legacy of Ammunition Lead (Pb) from Big Game Hunting in Sweden

In Sweden, a total of 5,880,688 moose ( Alces alces ), 1,084,671 fallow deer ( Dama dama ), 173,137 red deer ( Cervus elaphus ) and 7,911 brown bears ( Ursus arctos ) were harvested by recreational hunters in 1939–2024. In addition, 1,987,646 wild boars ( Sus scrofa ) were harvested in 1990–2024. To better understand the the potential for exposure of wildlife to lead (Pb), we estimated the amount of Pb from spent Pb-core hunting bullets in gut piles available to wildlife scavengers. Calculations were based on the number of harvested animals, the proportion of gut piles left in situ, the proportion of hunters using Pb-based ammunition, the number of shots per animal and the amount of Pb in each gut pile. Over the 86-year study period, we estimated that a total of ~ 9,045 kg of Pb from spent hunting ammunition was deposited in gut piles left for scavenging. This amount of Pb, which translates to > 450 million lethal doses for eagles weighing ~ 5 kg (0.02 g of Pb per bird), is likely to have resulted in harmful exposure in a wide range of avian and mammalian scavengers feeding on the gut piles. This source of Pb exposure could be eliminated from the ecosystem if Pb-based hunting bullets were banned.