Health and Disability

The latest and final in a series of congressionally mandated biennial reviews of the evidence of health problems that may be linked to exposure to Agent Orange and other herbicides used during the Vietnam War changed the categorization of health outcomes for bladder cancer, hypothyroidism, and spina bifida and clarified the breadth of the previous finding forParkinson's disease. The committee that carried out the study and wrote this report, Veterans and Agent Orange: Update 2014, reviewed scientific literature published between Oct. 1, 2012, and Sept. 30, 2014.

Bladder cancer and hypothyroidism were moved to the category of "limited or suggestive" evidence of an association from their previous positions in the default "inadequate or insufficient" category. A finding of limited or suggestive evidence of an association means that the epidemiologic evidence indicates there could be a link between exposure to a chemical and increased risk for a particular health effect. A finding of inadequate or insufficient evidence indicates that the available studies are of insufficient quality, consistency, or statistical power to permit a conclusion regarding the presence or absence of such a link. For both bladder cancer and hypothyroidism, new results from a large study of Korean veterans who served in the Vietnam War were compellingly suggestive of an association. In combination with pre-existing supportive epidemiologic findings and substantial biologic plausibility, the new information provided evidence to merit a change in category of association for these two outcomes.