From: Robina Suwol
Date: 24 Oct 2006
Remote Name: 220.127.116.11
Air Force Ignores Cancer Data on Agent Orange (Beyond Pesticides www.beyondpesticides.org )
October 11, 2006 Scientists who worked on a 25-year study of the impact of handling Agent Orange on the health of Air Force veterans says the Air Force left out evidence showing significant cancer effects. Joel Michalek, Ph.D., a statistician who worked on the study from the beginning and was its principal investigator for 14 years until he left in April, cited problems with the control group and said he found significant rates of cancer in both the Ranch Hand group, named after a corresponding Vietnam spraying mission, and its comparison group. Dr. Michalek's conclusions, published in two articles in the Journal of Occupational and Environmental Medicine in 2004 and 2005, were not included in the Air Force's $140 million final report on Agent Orange's impact on veterans' health.
Ronald Trewyn, Ph.D., biochemist at Kansas State University, and member of the Ranch Hand study advisory committee, reviewed the cancer chapter for that last report and argued that it should include data Dr. Michalek used to write the 2004 and 2005 articles. "They referenced those papers, but they left all the data out from those cancer papers that were done that showed the cancer effects."
Dr. Trewyn continued, "It's huge because then the conclusion is there's no cancer effect when as part of the study, the same investigators, just analyzing the data in a different way, found that when they did that, low and behold, then there were significant cancer effects. And so for the final report to say there's no cancer effect when the investigators themselves published papers saying there is a cancer effect, that's just flat scientifically wrong."
The Air Force reports spraying an estimated 368 pounds of the defoliant over the leafy jungles of Vietnam over a six-year period in an effort to expose enemy supply lines, sanctuaries and bases. Airmen were exposed to the sweet-smelling herbicide during spraying flights, while loading the chemical and while performing maintenance on the aircraft and the spraying equipment.
But Dr. Michalek says the exposure was wider because the defoliant was used to clear land for bases as well as for combat-related uses.
Since 1982, the Air Force's study has involved examining 1,000 "Ranch Handers" who handled the defoliant or came into contact with it, and about 2,000 other Air Force personnel not involved in the operation. Subjects were monitored every three to five years. The last report, based on testing done in 2002, concluded that the study "did not suggest an adverse relation between cancer and herbicide exposure." However, Dr. Michalek said more research needs to be done to determine whether airmen used as the control group in the study were also exposed to the chemical, and to figure out what other diseases the Air Force scientists may have missed because of the exposed comparison group. "That process was under way when I left ... to look at the exposure among members of the control group," Dr. Michalek told the Associated Press this month.
The Air Force said the study initially tried to compare the airmen who participated in spraying missions to a group not stationed in Southeast Asia, but there were not enough people to do that. The Air Force also said an earlier study of Agent Orange exposure showed that "current blood levels of dioxin in the vast majority of men who served as ground troops in Vietnam are indistinguishable from levels in the blood of similar veterans who did not serve in Vietnam." Dioxins are chemical compounds formed from various processes, including certain types of chemical manufacturing, such as making Agent Orange.
A Department of Veterans Affairs analysis in 1998 found that 5,908 claims for compensation related to Agent Orange had been approved out of 92,276 claims filed by veterans and their survivors. That was before diabetes was added to the list of diseases connected to Agent Orange, said Jim Benson, a spokesman for the Veteran Affairs Department.
Agent Orange is a 50-50 mixture of the herbicides 2,4-D and 2,4,5-T. All uses for 2,4,5-T were cancelled in 1985, however, 2,4-D is still one of the most widely used herbicides on lawns, school grounds and parks.