A study developed by Matthew S. Meselson, professor of Biology, has spurred the Department of Defense into action on defoliation in South Vietnam. The DOD has commissioned the National Academy of Sciences to do an in-depth study of the United States' use of herbicides.

A commission formed by Meselson stated that the United States' defoliation tactics in Vietnam have denuded one seventh of the land and may have caused a rise in birth defects. The final report will be published in book form this spring.

The Herbicide Assessment Commission was organized by the American Association for the Advancement of Science in December of 1969.

"We tried to cover as much as possible," Meselson said, "but the main points covered were the effects on crops and forests, in addition to the effects on humans."

The report stated that approximately 2000 square kilometers of land in South Vietnam have been sprayed in order to destroy the food-growing capabilities. The food destroyed would have fed approximately 600,000 people for one year.

"Our observations in Vietnam lead us to believe that precautions to avoid destroying the crops of indigenous populations have been a failure and that nearly all of the food destroyed would actually have been consumed by such populations." the report states.

The commission added that most crop destruction took place in the Central Highlands, the home of the Montagnards, a tribe racially and linguistically distinct from the Lowland Vietnamese.

When asked if the animosity between the lowlanders and Montagnards might have been a factor in the crop destruction, Meselson said, "The lowlanders' traditional dislike for the Montagnards may well have been one factor among the many which led to the lack of adequate precautions.

"More than one half of the Montagnards have been profoundly affected by the defoliation," Meselson added.

The less conclusive portions of the report are concerned with the effect of defoliants on humans.

The first area studied by the Commission was that of food chains. They concluded that dioxin, one of the impurities in the herbicide, is "exceedingly toxic, may be quite stable in the environment, and, being fat soluble, may be concentrated as it moves up the food chain into the human diet. Very rough calculations suggest that it is not impossible that significant amounts of dioxin are entering the Vietnamese diet."

Conclusive results cannot be obtained until more refined methods of determining the presence of the poison are discovered.

Conclusions

Laboratory experiments with the herbicide "Orange," showing that it caused birth defects in animals, led the Department of Defense last April to halt the use of the defoliant.

Over one half of South Vietnam's mangrove forests and one fifth of its hardwoods have been destroyed. Both are growing back at a slow rate, if at all.

"U. S. policy is changing, but we don't know whether we can ascribe any effect at all to our report. However, the White House is rapidly phasing out the use of herbicides," Meselson said.