Lead exposure from ammunition
Lead-based ammunition constitutes the largest unregulated source of lead in the environment in Norway (9). Both those using the ammunition and the surrounding environment are exposed, as lead dust settles on clothes and equipment. A study from the United States showed a correlation between lead exposure in children and the number of guns in their household (10). In Norway, there are more than 1.3 million registered civilian firearms (11), and nearly 500,000 Norwegians have one or more guns in their home.
Shooting and handling ammunition increases blood lead concentrations. Laidlaw et al. (12) reviewed 36 published articles with data on blood lead concentrations in shooters, and found that several had very high levels. Lead levels were associated with lead in aerosols when firing shots, the number of shots fired and the calibre of the weapon. We are aware of one study on blood lead concentrations in biathletes (13), which showed that the median blood lead concentration was more than twice as high in biathletes as in a comparable group of cross-country skiers.
Shooting is one of the most popular recreational sports in Norway, and lead-based ammunition is primarily used. On standard shooting ranges, the bullets are caught by a mound of earth or sand located behind the targets. In biathlon, metal targets, known as self-indicating targets, are mostly used. Upon impact with the metal, the bullet is pulverised, and lead fragments and dust fall to the ground. This lead will eventually disperse into the environment, thereby exposing all users of the facility. The primer in most types of ammunition is lead-based, and the gunpowder gas released upon firing also contains lead.
Norway has approximately 3000 active or decommissioned shooting ranges (14, 15). All are heavily contaminated with lead from ammunition and pose a health risk to humans, animals and the environment (14, 16, 17). In some cases, the concentration of lead is so high that the soil is classified as hazardous waste, i.e. > 2500 mg Pb/kg of dry matter (17–19). Thousands of tonnes of lead are present at active and decommissioned shooting ranges (14). In the summer of 2024, a cattle herd was exposed to lead at a biathlon range, where piles of pure lead were found under the targets (20). Three calves were found dead, while two others showed signs of acute lead poisoning. The sick calves had blood lead concentrations of 4.79 and 6.07 µmol/L (993 and 1257 µg/L), respectively. One calf died and the other was euthanised.
Bullets with lead cores are also commonly used for hunting large game such as moose and deer (21). The bullets fragment upon impact, depositing lead in the animal (22). Fragments larger than 0.1–0.2 mm are visible on X-rays and can be found at least 45 cm from the wound channel. Synchrotron X-ray can detect fragments smaller than 0.01 mm. These fragments are the size of a red blood cell and can circulate in the bloodstream to all parts of the body in animals that survive for some time after being shot. There can also be up to 50 million lead nanoparticles per gram of muscle tissue located near the wound channel. Nanoparticles can pass through intact cell membranes, including the blood-brain barrier (23).
Consuming meat from wild game shot with lead-based ammunition is associated with increased blood lead concentration, both in children and adults
Meat from wild game shot with lead-based ammunition can therefore contain significant amounts of lead. Two studies found that the average lead content in minced moose meat sold in Norwegian supermarkets was 18 and 56 times higher, respectively, than the maximum permitted limit for lead in livestock meat, which is 0.1 mg/kg (23). However, this legislation does not apply to wild game meat. Several studies have shown that consuming meat from wild game shot with lead-based ammunition is associated with increased blood lead concentration, both in children and adults (23, 24).
When hunting with shotguns, cartridges containing 200–500 round pellets of lead or other metals are used. Although lead shot is now banned for most types of hunting in Norway (25), enforcement is practically non-existent and compliance is unknown. Lead shot breaks into fragments and deposits lead around the wound channel. If ingested with food, lead shot can become lodged in the appendix and release lead over time. This is commonly observed in people who regularly eat meat from wild fowl killed using lead shot (23).
Lead from ammunition poses a threat to health in both humans and animals