THURSDAY, Feb. 28, 2002 (HealthDayNews) -- Last year's finding that exposure to Agent Orange was linked to a deadly form of leukemia in the children of Vietnam veterans was wrong, an expert panel of the Institute of Medicine says.
An Australian study that appeared to establish a connection between exposure and acute myelogenous leukemia (AML) contained a miscalculation "that led its authors to incorrectly conclude that these children faced a significantly greater risk of AML than the general population," a committee report says.
"Our review of available studies, combined with the revised analysis from Australia, indicates that the evidence is too weak to draw any conclusions or even make tentative ones," says a statement by Irva Hertz-Picciotto, committee head and a professor of epidemiology at the University of California at Davis.
The finding is based on an ongoing review of the medical literature, says David A. Butler, study director at the Institute of Medicine.
"The Agent Orange Act of 1991 directed the Department of Veterans Affairs to do a continuing study," Butler says. "The next large review will be the Agent Orange Update 2002, which will come out around the end of this year."
Previous reports by the institute found suggestive, but not conclusive, evidence that exposure to Agent Orange, a defoliant used in the jungles of Vietnam, was linked to an increased incidence of diabetes, respiratory cancer, prostate cancer and spina bifida in children of veterans.
In the case of AML, says David S. Strogatz, chairman of the department of epidemiology at the State University of New York School of Public Health, "there were three important studies that led the committee to the judgment that there was limited, suggestive evidence of an association. The change of results of the Australian study had the effect of removing one leg of a three-legged stool."
The new finding will be used by the Department of Veterans Affairs to make decisions on medical coverage for affected children, Butler says.
"Right now, the scientific evidence doesn't support a connection between this disease in the children of Vietnam veterans and Agent Orange exposure," says a statement by Anthony Principi, Secretary of Veterans Affairs. "If future studies reach the legal threshold, I will support creating benefits for these children of Vietnam veterans."
The new finding will have little practical effect, "because the AML fatality rate is almost 100 percent and children usually die before the age of 10," says Phil Kraft, director of the National Veterans Service Fund, a private organization that provides counseling for veterans. "What benefits would they be paying, besides death benefits?"
About 750 cases of AML are reported in children under 15 in the United States every year. It is a fast-spreading form of leukemia that originates in the bone marrow and accounts for about 8 percent of all childhood cancers.
Kraft says that while he appreciates the Department of Veterans Affairs' continuing effort to assess risk, "my bottom line is that there shouldn't be a list. There should be no questions asked about health care for Vietnam veterans and their families. The money they have spent on study after study after study could easily have financed a wonderful health-care plan."
Agent Orange and other defoliants were sprayed on a large scale in Vietnam and Cambodia, starting in 1962. Spraying stopped in 1970, after a scientific report concluded that dioxin, one of the primary ingredients in the defoliants, could cause birth defects in laboratory animals. Assessing the damage is hampered by a lack of information about exposure among troops in Vietnam. Most information comes from studies of civilian exposure on the job or from accidents.
What To Do
Dioxin is present in agricultural products being sold today, Strogatz says, so anyone working with those products should be aware of the dangers and take protective measures.
The revised report is available from the Institute of Medicine.
Visit the Department of Veterans Affairs for its take on Agent Orange. If you're interested in issues peculiar to Vietnam veterans, try the Vietnam Veterans of America .
