NCJ Number
190887
Date Published
1999
Length
318 pages
Annotation
This report reviews the scientific validity of the United States Army’s interim values for six chemical warfare agents -- tabun (GA), sarin (GB), soman (GD), organophosate nerve gas (VX) sulfur mustard, and lewisite.
Abstract
Some military bases contaminated with chemical warfare agents as a result of storage and past disposal practices are slated to be closed. 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, the Army developed interim chronic oral reference doses (RfDs) and, where appropriate, oral slope factors (SFs) for six chemical warfare agents that are likely to be encountered at contaminated sites. The Committee on Toxicology assessed the scientific validity of the interim RfDs by determining whether all the relevant toxicity data were considered appropriately; reviewed the uncertainty, variability, and quality of the data; determined the appropriateness of the assumptions used to derive the RfDs; and identified data gaps and make recommendations for future research. RfDs are toxicological values developed for noncancer effects and used as reference points to limit human oral exposure to potentially hazardous concentrations of chemicals thought to have thresholds for their effects. RfDs are estimates of daily oral chemical exposures that are unlikely to have deleterious effects during a human lifetime. For chemicals identified as carcinogens, SFs are also calculated. SFs are estimates of upper-bound lifetime cancer risk from chronic exposure to an agent. It was determined that the Army’s interim RfDs for tabun (GA), sarin (GB), soman GD, and sulfur mustard were scientifically valid but concluded that the RfDs for an organophosphate nerve agent (VX) and lewisite and the SF for sulfur mustard were too high. Research recommendations for filling major data gaps were also presented. See NCJ-190888-900 for additional chapters. Appendices