of exposure to herbicides and associated contaminants (dioxins). The task force was also asked to determine which adverse health effects are associated with exposure to dioxin, using the DVA standard of determination (Clapp et al., 1990).

On October 6, 1989, Edward J. Derwinski (then Secretary of Veterans Affairs) appointed Admiral E.R. Zumwalt, Jr., as a special assistant to help him in determining whether it is at least as likely as not that there is a statistical association between exposure to Agent Orange and specific health outcomes. On May 5, 1990, Admiral Zumwalt presented his report to the Secretary of Veterans Affairs. This report reviews relevant data in accordance with DVA standards relating to the evaluation of health effects of dioxin exposure. In addition to reviewing the data, Admiral Zumwalt reviewed the work of the DVA's Advisory Committee on Environmental Hazards' Scientific Council, and the protocol and standards employed by government-sponsored studies, to assess the credibility of these studies according to generally accepted scientific practice (Zumwalt, 1990).

Australia, New Zealand, and South Korea also sent troops to Vietnam to serve during the Vietnam era. In response to concerns of Australian veterans similar to those of American veterans about possible exposure to herbicides used in Vietnam, the Australian government conducted its own inquiries into the association between health effects and exposure to herbicides.

In October 1981, the Australian Senate Standing Committee on Science and the Environment undertook a study on pesticides and the health of Australian Vietnam veterans. This committee reviewed the use of pesticides, particularly phenoxy herbicides and chemicals containing dioxin, with reference to their ecological effects, and their effects on human and animal health, dealing primarily with the possible effects on Vietnam veterans of exposure to herbicides; it included all issues adversely affecting those who served in Vietnam. The Senate Standing Committee conducted 10 public hearings in several different cities in Australia as part of its inquiry (Australian Senate, 1982).

In May 1983, the Australian government established a commission to inquire about the use of chemical agents in Vietnam during the Vietnam era; the effects on Australian personnel of exposure to the chemical agents used; and the operation and administration of relevant Australian laws relating to claims by Australian personnel of chemical-caused disabilities (Evatt, 1985).

Approximately 4,700 South Korean veterans have filed claims with the South Korean Vietnam War Veterans Office, reporting that their medical problems appear to be related to Agent Orange. South Korea sent approximately