used to develop a model of exposure assessment for Vietnam veterans under the subcontract.

The RFP is intended to address assessment of all exposure to herbicides used during the Vietnam War. These herbicides are listed in Table 1. Several different herbicides and herbicide mixtures were used in varying combinations by the United States during the conduct of the war. Furthermore, some of these herbicides were contaminated with dioxins (TCDD and its congeners) at varying levels. Each of these chemicals has characteristics (e.g., half life and solubility) that will affect a person's dose at a given level of exposure. Because these chemicals also have distinctive toxicities, the proposal should acknowledge these complexities, not focus solely on TCDD. The proposal should address how exposure to this array of chemicals will be evaluated.

A paper included as the Appendix to this report is provided as background for potential respondents. This paper, entitled "The Assessment of Exposure to Herbicides among Vietnam Veterans: A Review and Recommendations for Future Studies," provides an overview of the U.S. military's use of herbicides during the Vietnam War, a review of prior exposure assessment research efforts, and a discussion of potential approaches to herbicide exposure assessment research. This paper was not written by the Committee on the Assessment of Wartime Exposure to Herbicides in Vietnam or any of its members, and it should not be viewed as instruction from the committee regarding the form or content of proposals. Instead, it should be treated as a summary of the information regarding exposure assessment contained in the IOM reports Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam and Veterans and Agent Orange: Update 1996.