Ecological and human health risks at an outdoor firing range

This is the first report in the refereed literature of a quantitative ecological and human health risk assessment at an outdoor recreational shooting range. Contaminants of concern (COC) included lead, other metals, and polycyclic aromatic hydrocarbons (PAH) associated with the clay targets on the shotgun range. Ecological receptors included raptors, deer, foxes, birds, and small mammals. The risk associated with potential incidental ingestion of lead shot by mammals was estimated for the first time. With the exception of lead, risks were minimal to all ecological receptors from all COC acting through all exposure pathways. Lead posed minimal risk to raptors, foxes, or deer. Lead in dietary items posed a small risk to individual birds. The only substantive risk was to individual small mammals and grit-ingesting birds from the incidental ingestion of lead shot within the shotfall zone at the trap and skeet range. Although effects associated with lead ingestion may occur at the level of individual organisms. ecological impacts are not expected at the population, community, or ecosystem level. This is because density-dependent compensation mechanisms would likely offset any site-related loss of a few individuals that might occur. Human receptors included shooters, range workers, and trespassers. Cancer risks to all receptors from all COC via all exposure pathways were less than 10(-4), generally considered an acceptable upper bound excess lifetime cancer risk to an individual. The only noncarcinogenic risk of HQ > 1 was associated with inhalation of copper by those engaged in the voluntary activity of shooting. Two approaches were taken to modeling blood lead in children associated with intermittent exposure. Under the most likely exposure scenario, the mean bleed lead level of trespassing children was approx. 2 mu g/dL, with less than 1% of children exceeding the 10-mu g/dL level of concern. Higher blood lead levels could be possible if children were to trespass in off-limit areas of the shooting range.