Agent Orange was the infamous herbicide sprayed extensively in Vietnam to defoliate leafy jungles and eliminate hiding places for enemy troops. Estimates are that the spraying may have boosted the risk of the rare illness, which chiefly strikes in infancy or early childhood, by between 70 percent and 300 percent, researchers say. Conducted by a University of North Carolina at Chapel Hill public health expert and a national committee of other experts, the study involved compiling and reviewing the best available research evidence of Agent Orange's effects. The National Academy of Sciences' Institute of Medicine convened the 2000 Committee to review the latest findings on the herbicide and asked Dr. Irva Hertz-Picciotto, professor of epidemiology at the UNC School of Public Health, to be chair.
Additional research is needed to shed more light on the issue.
Congress's Agent Orange Act of 1991 mandated that a series of studies be conducted every two years for 10 years to evaluate the effects of herbicides that were used in Vietnam on Vietnam veterans' health, she said. An interim committee on which I served also found limited suggestive evidence of a link between type II diabetes and herbicide use in Vietnam. After reviewing hundreds of studies from the United States and abroad, Hertz-Picciotto and colleagues found no reason to change decisions of previous committees about possible associations between herbicides such as Agent Orange and those five illnesses, the scientist said. The other, a study of what illnesses children of Australian Vietnam veterans had been diagnosed with, found a greater than four-fold risk although most confounding factors were not controlled for. While direct measures of herbicide exposures weren't available, the committee found the studies persuasive since they were conducted in Vietnam veteran populations and showed a specific link to AML and not to other leukemias, the scientist said.