SCIENCE IN THE NEWS #2074 - Agent Orange
By George GrowVOICE ONE:
This is Bob Doughty.
VOICE TWO:
And this is Sarah Long with Science in the News, a VOA Special English program about recent developments in Science. Today we tell about a chemical used by American forces during the Vietnam war in the Nineteen-Sixties and Nineteen-Seventies. It is called Agent Orange. It causes plants to lose their leaves. Studies say Agent Orange continues to affect people many years after the fighting stopped.
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VOICE ONE:
Monday was Memorial Day in the United States. Memorial Day is a holiday to honor Americans in the military who died in battle. This year, many Americans have been remembering the Vietnam War and events of twenty-five years ago. South Vietnamese forces officially surrendered to North Vietnam on April thirtieth, Nineteen-Seventy-Five. The Vietnam War affected the lives of millions of people twenty-five years ago. Today, it still affects many lives.
VOICE TWO:
During the war, American military forces attempted to destroy the natural hiding places of enemy forces. They sprayed about seventy-two-million liters of chemicals to kill plant growth over more than one-million hectares of what was then South Vietnam. They sprayed the chemicals between Nineteen-Sixty-Two and Nineteen-Seventy-One.
Most of the chemical mixtures contained dioxin. Dioxin is a substance known to cause cancer and birth defects in animals. The chemical mixture used most often was called Agent Orange.
VOICE ONE:
Many Americans who fought in Vietnam experienced health problems after the war. Hundreds of the veterans blamed Agent Orange.
One critic of Agent Orange was Elmo Zumwalt, Junior. Admiral Zumwalt served as Commander of American Naval Forces in Vietnam from Nineteen-Sixty-Eight to Nineteen-Seventy. Later, he served as Chief of Naval Operations and a member of the Joint Chiefs of Staff.
Admiral Zumwalt thought the United States should not have been involved in the Vietnam War. For him, the war represented a useless loss of life. It also represented a painful personal loss. His oldest son served with the American navy in Vietnam. Several years later, he died of cancer -- possibly caused by Agent Orange.
VOICE TWO:
Admiral Zumwalt had ordered the spraying of Agent Orange along rivers guarded by his son's boat. At the time, military officials did not know about the harmful effects of the chemical.
After he retired, Admiral Zumwalt worked to correct the wrongs done by Agent Orange. He said government officials refused to admit the harm that had been done to Vietnam veterans. He said there were attempts to hide the link between Agent Orange and the diseases it may cause.
VOICE ONE:
Veterans groups repeatedly criticized studies that showed little or no health problems caused by Agent Orange. One study in Nineteen-Ninety, for example, found no evidence of a link between Agent Orange and disease in humans. Another report said the chemical dioxin appeared to be less dangerous than some scientists believed. That study showed very high levels of dioxin can cause cancer in humans. But it also found dioxin might not be a cancer threat at lower levels.
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VOICE TWO:
In Nineteen-Ninety-One, Congress ordered an independent scientific study of the Agent Orange issue. The National Academy of Sciences organized the study. Congress also told the government to begin paying former soldiers who developed any of three diseases after serving in Vietnam. Two of the diseases are cancers - non-Hodgkin's lymphoma and soft tissue sarcoma. The other is a severe skin disease - chloracne.
In Nineteen-Ninety-Three, a committee of the Institute of Medicine released its report. Committee members studied almost six-thousand-five-hundred scientific reports about the effects on humans of the chemicals used to kill plants.
VOICE ONE:
The committee found a link between two other health conditions and Agent Orange. One is another kind of cancer - Hodgkin's disease. The second is a serious skin disease - porphyria cutanea tarda. The government added them to the list of diseases for which veterans can receive payment and free medical treatment.
Later, other cancers were added to the list. Government assistance also is offered to the children of some veterans. Studies found that veterans who worked with Agent Orange face an increased risk of having a child born with spina bifida. Spina bifida is a serious birth defect in which the baby's spinal cord is not completely covered.
VOICE TWO:
Earlier this year, the Defense Department released evidence linking Agent Orange to the disease diabetes. The new information came from a study of one-thousand former members of the Air Force. They all had worked on airplanes that sprayed Agent Orange or other chemicals. The study found that the Air Force veterans were more likely than other war veterans to get diabetes. It also showed that the disease seems to affect them sooner and more severely.
Medical experts are studying the findings. They may decide to add diabetes to the list of sicknesses linked to Agent Orange.
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VOICE ONE:
Agent Orange also has affected many people in other countries. The government of Vietnam estimates that more than two-million Vietnamese adults and their children have health problems caused by chemicals used during the war.
In March, American Defense Secretary William Cohen visited Vietnam. Vietnamese Prime Minister Phan Van Khai told Mr. Cohen that millions of Vietnamese have been affected by Agent Orange. The official said many families have three or four children born with physical disabilities.
Mr. Cohen offered to help Vietnam with joint health studies on the effects of Agent Orange. Vietnamese officials asked the United States to help the victims of the spraying.
VOICE TWO:
In Nineteen-Ninety-Four, a Vietnamese committee joined with a Canadian group, Hatfield Consultants, to begin studying the effects of Agent Orange. Research scientists selected the Aluoi Valley -- a place near the border with Laos -- as the main study area. The Aluoi Valley was heavily sprayed with Agent Orange and other chemicals from Nineteen-Sixty-Five to Nineteen-Seventy.
The study was designed to follow the movement of dioxin through the environment. The researchers tested soil from a farm and a former American military base. They also tested tissue from fish and ducks, and blood from people living in the area.
VOICE ONE:
Tests showed soil from the former military base had the highest levels of dioxin. Fish and material from waterways also had high dioxin levels.
Agent Orange dioxin also was found in human blood. High levels were found in people older than twenty-five, and in those between the ages of twelve and twenty-five. The researchers said the presence of dioxin in the young people provides evidence that the environment remains harmful. They say it shows dioxin is moving from the food grown in the area into humans.
VOICE TWO:
The researchers carried out more studies in the Aloui Valley last year. The new findings were announced last month. Tests confirmed higher than normal levels of dioxin in soil taken from the valley and in food. High levels of the chemical also were found in fish and bird tissues. And high levels were found in human blood and human breast milk collected from a village near the former military base.
The researchers say adults and children born after the war continue to eat foods with higher than normal dioxin levels. They say chemicals at the military base may be continuing to pollute the area.
VOICE ONE:
The problem of Agent Orange has been confirmed in other countries. Last year, American officials provided the government of Thailand with documents about Agent Orange testing in Thailand during the Nineteen-Sixties.
Also, the United States and South Korea have admitted that Agent Orange was used along the South Korean border with North Korea. It was sprayed to clear plant growth in Nineteen-Sixty-Eight and Nineteen-Sixty-Nine. The South Korean government has formed a group to investigate possible damage.
These discoveries show that the problem of Agent Orange is more widespread than anyone had thought.
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VOICE TWO:
This SCIENCE IN THE NEWS program was written by George Grow. This is Sarah Long.
VOICE ONE:
And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.
Source: www.voa.gov/special/