CHARACTERISTICS OF LEAD SHOT AND PARTICLES AT SHOOTING RANGES

Systematic studies of lead shot and related metals are being conducted at the public recreational shooting range in the Jefferson National Forest just west of Blacksburg, Virginia. This report only discusses the shotgun portion of the range. Detailed sampling of the shotgun range surface and surrounding area has revealed that the areas impacted by shooting are much greater than 0.7 acre cleared for the range and that the distribution of the lead is non-uniform. Shooting is either at at stationary or at airborne targets. Stationary target shooting concentrates lead and related metals at 25-30 meters from the shooting box where targets of extreme variety (from bottles to sofas and computers) are set. The slight incline of the range and nearly horizontal trajectory of fire concentrates the lead in the central area over a relatively short range of distances. In contrast, shotguns are fired at highly elevated angles when shooting at airborne targets. Consequently, most of the lead pellets are permitted to carry much greater distances. This study finds a peak of lead concentration at 80 to 100 meters from the shooting box and a gradual decrease in concentration out to 300 meters. The size of lead particles dispersed on the shotgun range vary widely because of (1) the differences in shot sizes used and (2) abrasion of lead to form small grains and shards. Most shot falling to the ground retain nearly spherical shapes and lie in the range of 2-3 mm. However, the discharge of shot from the shotgun barrel results in the generation and dispersal of fine particulate lead in areas close to the shooting box. In addition, the impact of lead pellets with targets and the ground at short distances also results in the abrasion of pellets and the release of fine lead particles in the range of 25-35 meters. The release of large quantities of fine particulate lead increases potential reactivity of lead in the environment and would make the recovery of lead more difficult.