to the Department of Veterans Affairs (VA) for service-connected disability for a variety of diseases and injuries increased. However, untangling the specifics of these claims presented major problems. For example, it was common for the periods of time spent as a volunteer in the gas experiments to be unaccounted for in official service records. Individual claimants therefore had great difficulty providing documentation of their participation in the testing programs. In addition, the assessment of the long-term health effects of sulfur mustard and Lewisite proved difficult. The vast majority of scientific and medical literature dealt solely with acute, short-term effects of these agents.

Pressure from individuals, the press, and Congress on the VA to resolve these issues increased over the intervening years and, on June 11, 1991, guidelines were announced by VA  Secretary Edward J. Derwinski for compensation of the veterans who had been subjects in the mustard and Lewisite testing programs. These guidelines loosened the normal restrictions on documentation for those veterans who participated in the testing programs and identified the diseases that the VA would consider to be residual effects of sulfur mustard or Lewisite. The diseases identified for compensation were laryngitis, chronic bronchitis, emphysema, corneal opacities, chronic conjunctivitis, and keratitis. Veterans filing claims believed that there were still other diseases caused by their exposure to these agents.

In addition to the changes in guidelines, Secretary Derwinski also requested the Institute of Medicine (IOM) to assemble a committee to survey the health effects of mustard agents and Lewisite. This request asked that special attention be paid to the long-term health effects of these agents and for the assessment to be based, to the degree possible within the time allowed and budget provided, upon published scientific literature dating back to 1917. This report results from the deliberations of the IOM Committee to Survey the Health Effects of Mustard Gas and Lewisite, whose specific charges were to

•  survey the published literature on the long-term health effects of mustard agents and Lewisite;

•  summarize the strength of association between exposure to these agents and specific diseases;

•  identify the gaps in knowledge regarding the contribution of exposure to these agents and disease; and

•  generate recommendations aimed toward decreasing the gaps in knowledge that may be found.

The committee met four times in the course of its work to consider as much of the scientific literature pertaining to mustard agents and Lewisite as possible. It was expected from the beginning that the scientific and medical literature would not be complete and that, for