A Cover-Up on Agent Orange?

By Ed Magnuson

The medical detectives at the Atlanta-based Centers for Disease Control have a well-earned reputation for relentlessly tracking down the causes of such mysterious ailments as Legionnaires' disease. But the agency's record is in danger of being blemished by a bitter controversy over Agent Orange, a defoliant containing dioxin, a suspected carcinogen.

Critics charge that the agency and one of its senior officials, Dr. Vernon Houk, helped scuttle a $63 million study that might have determined once and for all whether U.S. troops exposed to Agent Orange suffered serious damage to their health. Houk maintains he recommended that the study be canceled on strictly scientific grounds. Yet there is evidence that the CDC suppressed reports from the National Academy of Sciences that directly challenged its position, and spurned extensive help from the Pentagon, leading the White House to kill the study.

Agent Orange was widely used in Vietnam to strip the thick jungle canopy that helped conceal enemy forces; only later did scientists become aware of the potentially dangerous long-term effects of dioxin, which has produced cancers in animals. The defoliant has been suspect ever since unknown numbers of Vietnam veterans developed various cancers or fathered seriously handicapped children. Based on the inability to prove a conclusive link between those ailments and Agent Orange, the Reagan and Bush administrations refused to compensate veterans for all but a few of these health problems. But critics charge that no clear connections have been established because no serious large-scale study of exposed veterans has been done.

The most forceful complaints about the CDC have been leveled by former Chief of Naval Operations Elmo R. Zumwalt Jr. As the Navy's top commander in Vietnam, he ordered that Agent Orange be sprayed in the Mekong Delta region to destroy vegetation from which the Vietcong regularly launched ambushes against U.S. patrol boats. In 1988 Zumwalt's son Elmo III, a former lieutenant who had served in the "brown-water Navy," died from a rare lymphoma. Zumwalt believes his son's exposure to Agent Orange was responsible.

Last month Zumwalt told a House subcommittee that the CDC's work on Agent Orange had been "a fraud." He singled out Houk for having "made it his mission to manipulate and prevent the true facts from being determined." New York Congressman Ted Weiss, chairman of the panel, charged in an interview that the CDC appeared to have "rigged" its investigation to support its view that a large study of exposed veterans was not feasible.

Congress authorized the CDC study in 1982 after receiving thousands of complaints from Vietnam vets about Agent Orange. Houk, director of the agency's Center for Environmental Health and Injury Control, was placed in charge. At the White House, a science panel of the Agent Orange Working Group supervised the CDC's investigation. The Pentagon assigned its Environmental Support Group to provide the CDC with Agent Orange spraying records and those of the deployment of soldiers who may have been exposed.

But the study soon bogged down in a complex dispute over identifying which soldiers were likely to have been exposed to Agent Orange. The CDC considered a company of 200 men potentially exposed if it passed within 1.3 miles of a recently sprayed area. The Army had fairly detailed records on the daily positions of its companies during the fighting. There were gaps, but the Pentagon group repeatedly told the CDC that other documents, such as daily journals and situation reports, could be used to pinpoint which units had ventured into areas sprayed with the defoliant. Houk's team complained that the Pentagon data were too spotty to determine whether companies had been deployed in normal formations spread over 200 to 300 yards or dispersed over distances of up to 12 miles. It stubbornly refused to make use of the other records.

By late January 1986, Dr. Carl Keller, chairman of the White House science panel, and several other of its members concluded that Houk had already decided that the CDC study was not feasible and was trying to pin the blame on the Pentagon. To break the impasse, retired Army Major General John Murray was asked by Defense Secretary Caspar Weinberger to review the Pentagon records. After a four-month study, Murray thought the records were useful. But as a nonscientist he did not feel competent to rebut the objections raised by Houk and the White House scientists. He gave up, agreed that the information was inadequate and suggested cancellation of the project.

Unknown to Murray and the White House, the Institute of Medicine, an arm of the National Academy of Sciences, then turned in a contracted consultants' report to the CDC on the Agent Orange study. It concluded that the Pentagon group was fully capable of "determining locations and filling gaps" in the troop movements and criticized the CDC's study for excluding many of the veterans most likely to have been exposed. The CDC never turned the institute's report over to the White House.

Murray presented his conclusions at a White House meeting on May 27, 1986. The White House moved to kill the study unless other ways could be found to identify exposed soldiers. Much later, Murray learned of the institute's report and began to doubt his recommendation. "I may have been a babe in the woods," he said in an interview. "My feeling now is that this whole thing deserves another look."

Instead of killing the project outright, the White House panel accepted a proposal by Houk to take blood tests of 646 Vietnam veterans, selected on the basis of their probable exposure, to see if they had elevated blood levels of dioxin. The tests showed that none had abnormal blood levels -- not surprising, given that the exposure would have taken place 20 years earlier and that none of those tested had handled Agent Orange directly.

Though many scientists ridiculed the blood tests, Houk used them to contend again that the Pentagon records could not be used to pinpoint exposure to Agent Orange. He recommended canceling the study; the White House Science Panel agreed, and the Domestic Policy Council did so in September 1987. This was after $43 million had been spent.

Once again the White House had acted without having all the facts. The Institute of Medicine only weeks earlier had written a blistering review of the CDC's work. It urged that each of the agency's major conclusions be deleted because the evidence presented by the CDC did not support them. The White House never received this devastating report.

Houk insists that his opposition to continuing the project was based solely on rigorous scientific principles. "If we could find a population of people who were exposed in sufficient numbers, we would have proceeded with our study," he says. "We just simply could not find them." Skeptics like Congressman Weiss suspect that the CDC did not want to antagonize the Reagan Administration, which was worried about the huge liability costs if Agent Orange was shown to cause the veterans' ailments. Whatever the reasons for its failure, the decision not to complete the study leaves open a vexing problem: whether Agent Orange will exact a toll on Vietnam vets and their descendants for generations to come.

With reporting by Jay Peterzell/Washington