Agent Orange-Spina Bifida Link:
Let's Look Again

Michael Gough
Cato Institute
April 1996

A new study by the Institute of Medicine (IOM) may open the floodgates for opportunistic lawsuits and unnecessary government regulation, highlighting once again the dangers of basing public policy on "junk science."

The IOM report Veterans and Agent Orange: Update 1996, released last week, concludes that there is "limited/suggestive evidence" for an association between a man's exposure to Agent Orange and the birth defect, spina bifida, in his children. That conclusion is not consistent with the analyses of other scientists. The next 90 days may provide an opportunity for the its scientific review. That review can play a major role in the expected debate about whether the Department of Veterans Affairs (VA) should compensate children with the birth defect and influence the number of lawsuits charging that exposures to herbicides, such as Agent Orange, have caused birth defects or increased the risks of birth defects.

Disputed Science

The basis for the IOM conclusion is a study of children born to former members of Operation Ranch Hand, the U.S. Air Force unit that sprayed 90 percent of the Agent Orange used in Vietnam. The authors of the Ranch Hand study, the advisory group to that study (I chaired that group at the time the birth defects study was reviewed), and the reviewers and editors of the journal in which the Ranch Hand birth defects study was published all concluded that the study showed no association between Agent Orange and birth defects.

Dioxin, always present in Agent Orange, is the focus of research on possible health effects of Agent Orange; conclusions about dioxin are tantamount to conclusions about Agent Orange. Many of the alleged human health effects of dioxin have fallen by the wayside, and both the Science Advisory Board of the Environmental Protection Agency and the French Academy of Sciences found no linkage between dioxin and birth defects and concluded that the only human illness definitely linked to dioxin is a skin disease.

The chairman of the IOM panel said that this latest conclusion about spina bifida requires more study, but it is difficult to imagine what there is to study. An excellent animal study has been done, and no populations of humans exposed to high concentrations of dioxin remain to be studied.

Doses of Agent Orange sufficient to cause overt toxicity and decreased sperm counts in male mice caused no increase in birth defect rates. There seems little point in repeating such an experiment. Because of concern about dioxin, manufacture of the dioxin-contaminated component of Agent Orange was terminated in the 1980s, so there are no populations of highly exposed people, such as factory workers, who have not already been studied.

What is now known about human effects is likely to be all that is ever available. What is known is worthy of another examination in full public view before the VA makes any decisions.

"Evidence" and the VA

VA secretary Jesse Brown has formed a working group to advise him before he makes a decision about whether the VA should compensate veterans' children. The working group must report to Brown in 90 days. This period for consideration is a welcome change from past VA policy based on "limited/suggestive" evidence.

The first IOM report on Agent Orange and Vietnam veterans, in 1993, concluded that there was "limited/suggestive" evidence of a connection between exposure to Agent Orange and lung cancer, prostate cancer, and multiple myeloma. Almost immediately, and without further consideration, the VA decided to compensate for respiratory cancers and multiple myelomas. Through November 1995, the VA had paid compensation to some 3,000 Vietnam veterans. That may be the only instance where compensation for lung cancer was handed out without consideration of smoking history.

A Chance for Re-examination

New legislation is required before the VA can pay compensation for diseases and disabilities in members of veterans' families. Such a program for spina bifida would not break the budget. If every one of the 2.7 million Vietnam veterans has one child and spina bifida occurs at the usual rate in their children, there will be only about 1,350 veterans' children with the birth defect.

If the VA decides to compensate -- whether on the basis of either the IOM report alone, or of further review -- far greater costs can be expected from the large number of potential lawsuits from the general public claiming that environmental exposure caused spina bifida. VA compensation would also renew calls for even stricter regulation of dioxin, with attendant administrative hearings and additional tests and studies (whatever they might be). Such costly burdens should never be put in place on the basis of disputed science.

More important than monetary costs, establishing government policy on the basis of disputed and uncertain science is simply wrong. The VA working group and congressional hearings, if properly managed, offer an opportunity to revisit the science.

If the review corroborates the IOM conclusions, the VA will be on firmer ground. If it does not, and VA or Congress decides against compensation, the VA will have acted on the basis of sound science. That makes sense.

Michael Gough is director of science and risk studies at the Cato Institute and the author of Dioxin, Agent Orange (Plenum Press, 1986). He formerly served as senior associate at the Office of Technology Assessment.

Material presented on this home page constitutes opinion of the author.