The US Congress passed the Agent Orange Act of 1991 to address whether exposure to herbicides, such as Agent Orange, contributed to long-term health effects in Vietnam veterans. The Act directed the Institute of Medicine to perform biennial comprehensive evaluations of the scientific evidence of exposure and possible health effects and publish their findings.
Veterans and Agent Orange: Update 2014 (released March 2016) is the tenth and last congressionally-mandated update. Based on the body of evidence, the Update 2014 committee changed the categories of association with exposure to the herbicides sprayed in Vietnam for three health effects.
Bladder cancer and hypothyroidism were moved from “inadequate or insufficient” evidence of association up to “limited or suggestive” evidence of association, while the birth defect spina bifida in the offspring of Vietnam veterans was demoted from “limited/suggestive” down to “inadequate/insufficient.”
The committee clarified that Vietnam veterans with “Parkinson-like symptoms,” but without a formal diagnosis of Parkinson disease, should be considered eligible under the presumption that Parkinson's disease and the veterans' service are connected. The committee also identified recommendations for the continued monitoring of the health of Vietnam veterans, and outlined procedures to help ensure that military personnel are followed from the time they are deployed in order to anticipate service-related health effects that could arise later in life.