Why was the CDC Agent Orange Study cancelled?

In December 1979, Congress directed the Veterans Administration, now known as the Department of Veterans Affairs (VA), to conduct a large-scale epidemiologic study to determine if Agent Orange has caused health problems in Vietnam veterans. For approximately 3 years VA and its contractor attempted to develop an adequate protocol or study design. VA, at the suggestion of Congress, then transferred responsibility of the study to the Centers for Disease Control (CDC).

Unfortunately after several years of research, CDC found that military records were unable to identify individuals who were exposed to Agent Orange in Vietnam. Subsequently, CDC did a special Agent Orange Validation Study to determine the feasibility of conducting the Agent Orange Study using indirect estimates of exposure to Agent Orange from military records (and self reports) and by comparing such measures with serum levels of 2,3,7,8-TCDD (dioxin). CDC maintained that the findings of the Agent Orange Validation Study confirmed conclusively that neither military records nor veterans' self reports of exposure to Agent Orange can identify exposed individuals needed for a full scale study.

This conclusion was agreed to by a CDC advisory group, the Science Panel of the Domestic Policy Council Agent Orange Working Group, and the Agent Orange Advisory Panel of the Congressional Office of Technology Assessment. Consequently, the study was canceled. Some people believe that an index of Agent Orange exposure for ground troops could still possibly be developed.

What can be done?

While the CDC Agent Orange Study could not be successfully completed, a substantial number of related research efforts have been completed and published, and other scientific studies are ongoing. VA, CDC, Air Force, and several other departments, agencies and organizations have been doing this important research. For information about these projects, see Agent Orange Brief, C2 and C3.

In July 1993, the Institute of Medicine (IOM) of the National Academy of Sciences recommended that a nongovernmental organization with appropriate experience in historical exposure reconstruction be commissioned to develop and test models of herbicide exposure for use in studies of Vietnam veterans. The IOM further recommended that these models be evaluated by an independent nongovernmental scientific panel established for this purpose. The IOM indicated that if the panel determines that a valid exposure reconstruction model is feasible, VA and other government agencies should facilitate additional epidemiologic studies of Vietnam veterans. Secretary Brown concurred, and VA is taking action to implement these recommendations where feasible. At VA's request, IOM is attempting to determine the feasibility of developing an useable herbicide exposure reconstruction model.

Who should be contacted for additional information regarding the cancellation of the CDC Agent Orange Study and the difficulties experienced in pursuing Agent Orange research?

Questions concerning the CDC Study can be directed to the Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30333. Other matters can be handled by the Registry Physician at the nearest VA medical center or by the Environmental Agents Service (131), Department of Veterans Affairs, 810 Vermont Avenue, N.W., Washington, DC 20420.