2602 Environmental Toxicology and Chemistry, Vol. 19, No. 10, pp. 2602–2613, 2000  2000 SETAC Printed in the USA 0730-7268/00 $9.00 + .00 Hazard/Risk Assessment ECOLOGICAL AND HUMAN HEALTH RISKS AT AN OUTDOOR FIRING RANGE RICHARD K. PEDDICORD*² and J UDY S. LAKIND‡ ²Dick Peddicord & Company, P.O. Box 300, Weems, Virginia 22576, USA ‡LaKind Associates, LLC, 106 Oakdale Ave, Catonsville, Maryland 21228, USA ( Received 17 September 1999; Accepted 3 March 2000) Abstract—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 hydro- carbons (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 blood lead level of trespassing children was approx. 2 g/dL, with less than 1% of children exceeding the 10-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. Keywords—Lead Firing range Blood lead Copper Mammals BACKGROUND Target shooting is a popular recreation, with approx. 12,800,000 annual participants in the United States, including nearly 5,000,000 women (http://www.nsga.org/guests/ research/participation/participation.html; [1]). Outdoor rifle, pistol, and shotgun ranges can introduce substantial amounts of lead and other metals into the environment in the form of spent bullets and shot. Several authors [e.g., 2–4] have studied various aspects of the potential environmental implications of outdoor shooting ranges. However, this is the first quantitative ecological and human health risk assessment of outdoor shoot- ing ranges in the peer-reviewed literature. The Blue Mountain Sportsman’s Center (Center) is a rec- reational outdoor shooting facility operated by Westchester County, New York, approx. 40 mi north of New York City (NY, USA). The facility includes pistol, large-bore, and trap and skeet ranges. The ranges are located sequentially down the valley of a small stream in wooded hilly terrain and are interspersed with wooded and vegetated wetland areas on and between the ranges. Both upland and wetland areas contain spent bullets and shot, and the trap and skeet range contains fragments of clay targets. Throughout this paper, ‘‘on site’’ refers to areas of the Center occupied by shooting ranges where spent bullets, shot, or other residues from shooting activities are present. ‘‘Off site’’ refers to the much larger remaining area of the Center unaffected by shooting. The five metals and 16 polycyclic aromatic hydrocarbons identified as contaminants of concern in the ecological and human health risk assessment are identified in Table 1. * To whom correspondence may be addressed (dp@rivnet.net). The metals derive primarily from bullets and shot. The PAHs derive from the clay targets used on the trap and skeet range [3]. There are sufficient toxicological data to establish that these COC, depending on environmental conditions and concentrations, may pose some potential risk to ecological receptors and humans [5–12]. Samples of soil, sediment, and surface water and air were collected and analyzed for COC [13]. Concentrations (95% upper confidence limit on the mean) of selected COC are presented in Table 2. ECOLOGICAL RISK ASSESSMENT Introduction The Center contains diverse wetland and terrestrial habitats. Wetland habitats include freshwater marshes, bogs, and wood- ed areas with a small brook and a few interspersed pools. Terrestrial habitats include old-field growth and mixed conif- erous and deciduous woodlands, with black and red oak, east- ern hemlock, red maple, and black gum common. The primary source and release mechanisms for contaminants are the shoot- ing of lead bullets and shot at the various ranges and the breaking of clay targets on the trap and skeet range. The stream and marsh sediments and surficial soil are secondary sources since they contain the spent bullets, shot, and target fragments. Although the particulate lead, other metals, and PAHs in soil and sediment may pose a potential risk to ecological receptors, various secondary release mechanisms may alter the distri- bution and bioavailability of contaminants. Metals and PAHs can dissolve in rainwater and dew and wash into surface water. Transformation processes could release metals, including ox- ides of lead, and/or PAH to soil and sediment. Contaminants may be taken up by vegetation or lower-trophic-level animals,