Sites wildlife exposure assessments

Exposure assessment includes both qualitative and quantitative evaluations of the potential for exposure to site-related chemicals to occur. Assessments commonly address both current and likely future uses of the property (e.g., residential, commercial, industrial, and agricultural). Typically, a conceptual model is developed that summarizes how site-related chemicals may contact receptors (e.g., humans, wildlife, and ecological). The model includes identification of chemical sources, impacted media, potential movement through the environment, identification of the appropriate exposure scenarios, and identification of the points at which contact between receptors and site-related chemicals are likely to occur. Chemical concentrations in environmental media may be estimated based on site data and using statistical analyses and/or fate and transport modeling. An estimate of the dose (intake) attributable to contact with environmental media through significant and completed pathways is made for chemicals of concern at... 

Island would likely become a national wildlife refuge. The cleanup standards, which EPA would establish for each end use scenario, differ in terms of receptors and exposures to inhabitants, which should be defined in an appropriate risk assessment. Receptors are plants, biota, animals, and humans that are exposed to a contaminant of concern. The risk assessment should assess the risks to both human health and ecological receptors, because they may require different end states. PMCD assigned the U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) to prepare the Conceptual Site Model (CSM) for JACADS closure and to perform the risk assessment. 

To ensure that chemical contamination is rednced to safe concentrations at stockpile and NSCM sites before they are used for residential, occupational, or wildlife purposes, the U.S. Army requested that health-based exposure limits for GA, GB, GD, VX, sulfur mustard, and lewisite be developed to protect the pnblic and the environment. Oak Ridge National Laboratory (ORNL) was asked to conduct the health risk assessments and propose chronic oral reference doses (RfDs) and, where... 

While sufficient evidence indicates the toxicity of many EMs to soil and aquatic invertebrates and to fish occurs at concentrations expected or reported for contaminated sites, toxicological studies have also indicated that only exceedingly high concentrations cause adverse effects on most wildlife species. Additional toxicity data and more accurate risk assessment techniques will be required to more accurately characterize the EM exposure risk to further improve contaminated site management decisions. 

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