Reference dose , chemical warfare agents

Subcommittee on Chronic Reference Doses for Selected Chemical Warfare Agents, National Research Council... 

SUBCOMMITTEE ON CHRONIC REFERENCE DOSES FOR SELECTED CHEMICAL-WARFARE AGENTS... 

Several military bases contaminated with chemical-warfare agents as a result of storage and past disposal practices are slated to be closed pursuant to the Base Realignment and Closure Act. Before those military bases can be transferred to civilian use, contaminated soil and water must be cleaned to levels that are considered safe. To help make decisions on restoration required at contaminated sites and on the potential uses of the former military installations (e.g., for housing, occupational, or wildlife purposes), the U.S. Army developed interim chronic oral reference doses and, where appropriate, oral slope factors for six chemical-warfare agents that are likely to be encountered at contaminated sites. Similar information for inhalation exposure is under development. 

In this report, the Subcommittee on Chronic Reference Doses for Selected Chemical-Warfare Agents of the National Research Council s (NRC s) Committee on Toxicology reviews the scientific validity of the Army s interim values for the six chemical-warfare agents—GA, GB, GD, VX, sulfur mustard, and lewisite. The NRC report is intended to be useful to the Army in making site-specific cleanup decisions. 

TABLE S-1 Reference Doses and Slope Factors for Six Chemical-Warfare Agents... 

Opresko, D.M., R.A. Young, R.A. Faust, S.S. Talmage, A.P. Watson, R.H. Ross, K.A. Davidson, and J. King. 1998. Chemical warfare agents Estimating oral reference doses. Rev. Environ. Contam. Toxicol. 156 1-183. 

National Research Council (NRC), Committee on Toxicology, Subcommittee on Chronic Reference Dose for Chemical Warfare Agents (1999). Review of the US Army s Health Risk Assessment for Oral Exposure to Six Chemical Warfare Agents. National Academy Press, Washington, DC. 

NRC (National Research Cormcil) (2003). Acute Exposure Guideline Levels for Selected Airborne Chemicals. Suhcommittee on Chronic Reference Doses for Selected Chemical-Warfare Agents, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission on Life Sciences, National Research Cormcil. National Academy Press, Washington, DC. 

Crossgrove, R. (ed) (1999). Evaluation of the Army s Interim Reference Dose and Slope Factor for Sulfur Mustard from Review of the U.S. Army s Health Risk Assessments for Oral Exposure to Six Chemical-Warfare Agents, pp. 70-82. See NCJ-190887 and http //www.ncjrs.gov/App/Publications/ abstract.aspx ID=190893... 

Opresko DM, Young RA, Faust RA et al. (1998). Chemical Warfare agents estimating oral reference doses. Rev Environ Contam Toxicol, 156, 1-183. 

Methods used to derive oral reference doses for chemical warfare agents follow standard EPA protocols (EPA, 1989 Dourson, 1994), employ appropriate toxicological data, and have undergone review for consistency by the NRC (Bakshi et al, 2000 Opresko et al, 1998, 2001), Because the EPA has nt)t officially verified the derived values for nerve agents, they are identified and referenced as estimated RfDs (RfD ). 

The oral Reference Doses (RfDg) calculated in this report for chemical warfare agents, together with the Uncertainty and Modifying Factors used in their derivation, are listed in Table 38. Data were insufficient for deriving RfDeS for agents HT, T, and HN2. 

Health risk assessments for sites contaminated with chemical warfare agents require a comparison of the potential levels of exposure with a characterization of the toxic potency of each chemical. For noncancer health effects, toxic potency is expressed in terms of Reference Doses (RfD). 

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