Agent Orange may have killed GIs' kids

Evidence of link to fatal type of leukemia, but no proof that herbicide was cause  

David Brown / Washington Post 20apr01

[Reuters 19apr01 story below]

Washington -- A panel of scientists said yesterday there is some evidence of a link between a soldier's exposure to the herbicide Agent Orange during the Vietnam War and his children's risk for a specific form of cancer.

This is the second time in the past decade that experts at the National Academy of Sciences' Institute of Medicine have judged a childhood disease to be possibly caused by parental contact with toxic chemicals during the Vietnam War.

Although the connection between Agent Orange and acute myelogenous leukemia in children is weak, the secretary of veterans affairs, Anthony Principi, said he will seek congressional authority to make disability payments to veterans' offspring who may have survived the disease. How many people that may be is uncertain, however, as the cancer is rare and usually fatal.

More significant than the practical effects of the finding is the fact that it signifies the continuing expansion of the list of diseases possibly linked to the notorious defoliant. About 18 million gallons of herbicide were sprayed on Vietnam between 1962 and 1970, more than half of it Agent Orange, which contained the toxic compound dioxin.

Nine diseases, including lung cancer and prostate cancer, are on the list. Adult-onset diabetes is about to be added. The one other childhood condition is spina bifida, a birth defect that sometimes causes paralysis.

For purposes of compensation, the Department of Veterans Affairs assumes that everyone who served in Vietnam was exposed to Agent Orange. A veteran claiming disability from an officially herbicide-linked ailment doesn't have to prove actual exposure.

The academy's Institute of Medicine panel, consisting of 10 epidemiologists, toxicologists and physicians, specifically found "limited/suggestive evidence of an association" between herbicide exposure and leukemia.

The panel based its leukemia recommendation largely on three studies. One found that children with leukemia were more likely to have parents who reported exposure to pesticides than children without the disease. A second found that children with leukemia were more likely to have parents who had served in Vietnam or Cambodia than healthy children. The third study reported an unexpectedly high number of leukemia cases in the children of Australian Vietnam veterans.

"This does not establish that there is a causal association," said Irva Hertz-Picciotto, an epidemiologist at the University of North Carolina, who chaired the panel. What it says is that there may be some connection between Agent Orange exposure and the cancer, although it could be occurring by chance, she said.

Two things suggest a true connection, she said. One was that the more common childhood leukemia, acute lymphocytic leukemia, showed no link to herbicide exposure. The second was the predominance of acute myelogenous leukemia cases in children under age 2 in the studies. When the disease occurs at such a young age, there is a greater chance it arises from preconception parental exposures than when it occurs at an older age.

Government officials estimate there may be 500 to 1,000 children of Vietnam veterans who had acute myelogenous leukemia. The majority of children with the disease die.

Only 8,600 of the roughly 2.3 million surviving Vietnam veterans have sought disability compensation for an Agent Orange-linked disease.

Study looks at Agent Orange and child cancer

Sue Pleming / Reuters 19apr01

WASHINGTON -- There may a link between the dioxin-laced herbicide Agent Orange sprayed widely in the Vietnam War and a form of childhood leukemia found in veterans' children, said an official report released on Thursday.

The Institute of Medicine of the National Academies, an independent research body that often advises government, stopped short of establishing a direct connection between the herbicide and leukemia but said there was "limited or suggestive" evidence of such a link.

The report, ordered by Congress in response to concerns by Vietnam veterans and their families, reviewed the findings of two studies in particular that looked at the link between acute myelogenous leukemia (AML) in veterans' children and herbicides including Agent Orange.

"No firm evidence links exposure to the herbicides with most childhood cancers but the new research does suggest that some kind of connection exists between AML in children and their fathers' military service in Vietnam or Cambodia," said committee chair Irva Hertz-Picciotto, professor of epidemiology at the University of North Carolina, Chapel Hill.

Hertz-Picciotto said additional studies were needed to shed more light on the impact on veterans' children of Agent Orange, named after the striped orange barrels used to transport it.

"What is significant here is that this is a second-generation possible effect of Agent Orange," she told Reuters.

U.S. forces sprayed some 19 million gallons (72 million litres) of herbicides, of which Agent Orange is the best known, over southern Vietnam during the war to deny Communist guerrillas jungle cover.

Hanoi blames Agent Orange for causing tens of thousands of birth defects in Vietnam and has demanded compensation.

The U.S. government has consistently said a link remains to be proven between Agent Orange and hereditary birth defects. A U.S. Air Force study released last year, however, did show a significant link between it and diabetes in veterans.

In the studies on AML, the strongest link was seen in children diagnosed at the youngest ages, a pattern that suggested that the cause of a disease stems from a parent, said Hertz-Picciotto.

A third study found that the development of AML was more likely in the children of men who used pesticides or herbicides in their work, Hertz-Picciotto said.

The evidence in the new report was rated as "limited or suggestive" because while there was evidence of a link between exposure and the disease, it was not conclusive enough to say other factors did not influence the results.

Research into the health impact of Agent Orange had been hampered by inadequate information about exposure levels of troops in Vietnam, the report said.

"The research has just not been done in which we can say these people served here and so this is the exposure-level they got," said Hertz-Picciotto.

The National Academies was mandated by Congress to conduct two-yearly studies over a decade on the impact of Agent Orange on the health of veterans. The first report was released in 1994 and the final one will be in two years.

Earlier reports found evidence of a link between exposure to herbicides and soft-tissue sarcoma, Hodgkin's disease, non-Hodgkin's lymphoma and chloracne in veterans.

Hertz-Picciotto said additional studies provided "limited" evidence of diabetes, respiratory cancers, prostate cancer and multiple myeloma as well as the congenital birth defect spina bifida in veterans' children.

Most widespread sprayings of Agent Orange were conducted from airplanes and helicopters but some of the herbicides were dispersed from boats and ground vehicles or by soldiers wearing back-mounted equipment.

A 1969 study concluded that one of the primary chemicals in Agent Orange could cause birth defects in laboratory animals. The U.S. military suspended the use of Agent Orange in 1970 and halted all herbicide spraying in Vietnam the following year.

A Pentagon spokeswoman said the defense department would review the latest report before commenting on it.