From 1962 to 1971, US military sprayed herbicides over Vietnam to strip the thick jungle canopy that could conceal opposition forces, to destroy crops that those forces might depend on, and to clear tall grasses and bushes from the perimeters of US base camps and outlying fire-support bases. Because of continuing uncertainty about the long-term health effects of the sprayed herbicides on Vietnam veterans, Congress passed the Agent Orange Act of 1991. The legislation directed the Secretary of Veterans Affairs to request the Institute of Medicine to perform a comprehensive evaluation of scientific and medical information regarding the health effects of exposure to Agent Orange and other herbicides used in Vietnam. 

Veterans and Agent Orange: Update 2008 is the eighth report in this series. The authoring committee found suggestive but limited evidence that exposure to Agent Orange and other herbicides used during the Vietnam War is associated with an increased chance of developing ischemic heart disease and Parkinson's disease for Vietnam veterans.