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 Press Release

March 10, 2002

U.S., Vietnam Sign Agreement on Joint Agent Orange/Dioxin Research

Press Release


Meeting of the Vietnamese and United States Delegations in Follow-Up to the Joint Vietnam-US Scientific Conference on Human Health and Environmental Effects of Agent Orange/Dioxin Hanoi, Vietnam

March 10, 2002

On March 3-6, 2002, the Vietnamese and United States Governments sponsored a scientific conference in Hanoi,Vietnam to exchange information on the health and environmental effects of Agent Orange and dioxin. This unique conference brought together scientists from Vietnam, the United States and 11 other countries to discuss the state-of-the-art of research into the health effects of dioxin. On the day following the conference, March 7, 2002, a select panel of international scientists identified data gaps in our understanding of the health and environmental effects of dioxin and recommended general areas of research in Vietnam that would help to fill these data gaps.

On Friday, March 8, 2002, senior scientists from the Vietnamese Ministry of Science, Technology and the
Environment, the Vietnamese Ministry of Health, the US National Institute of Environmental Health Sciences, the US Environmental Protection Agency and the US Centers for Disease Control and Prevention met in Hanoi to establish an agreement for future research activities using the findings from the three-day conference and one-day workshop as a guide. The Vietnamese and US Government Agencies agreed to the following joint research plan.

Two major areas of research were addressed at the Hanoi conference: direct research on human health outcomes from exposure to dioxin and research on the environmental and ecological effects of dioxin and Agent Orange. In both of these areas, the workshop participants identified critical research needs; the highest priority areas are outlined below.

Areas of Research to be Developed

Priorities for Health Research

The primary concerns in Vietnam from prolonged exposure to dioxin are for reproductive and developmental disorders that may be occurring in the general population. The key areas for research in Vietnam include spontaneous abortions, miscarriage, premature birth, congenital malformations,
endocrine disorders, neurological disorders, immunodeficiency, cancer, genetic damage and diabetes
mellitus. US and Vietnamese scientists will review the available literature and set priorities for areas where both determine that the literature is insufficient to determine the presence or absence of a hazard and more research is needed.

Preliminary discussions have suggested two areas of research that should be further developed; research on existing populations with high exposures to dioxin relative to populations with low exposures (for example, people living near hotspots) and research on therapies to reduce dioxin body burdens in humans (such as some herbal therapies being proposed in Vietnam). Further discussions of this research should seriously consider and be guided by the recommendations of the health scientists involved in the
consultative workshop held on March 7, 2002 (attached as Annex 1).

Priorities for Environmental Research

Dioxin contaminants of Agent Orange have persisted in the environment in Vietnam for over thirty years. In addition to a better understanding of outcomes of exposure, an improved understanding of residue levels and rates of migration of dioxin and other chemicals in the environment is needed. "Hot spots" containing high levels of dioxin in soil have been identified and others are presumed to exist but have yet to be located. Dioxin has migrated through soil and has been transported through natural processes such as
wind-blown dust and erosion into the aquatic environment. Contamination of soil and sediments provides a reservoir source of dioxin for direct and indirect exposure pathways for humans and wildlife. Movement of dioxin through the food web results in bioconcentration and biomagnification with potential ecological impacts and continuing human exposure.

Research is needed to develop approaches for more rapid and less expensive screening of dioxin residue levels in soil,sediment, and biological samples which can be applied in Vietnam. Improvements in this first step of analysis should be complemented by efforts to upgrade capabilities of laboratory facilities and equipment to international standards required by the research needs. These improved analytical capabilities can then be used to more readily determine locations of highly contaminated areas, monitor
remediation and understand migration of dioxin in the natural environment. Monitoring efforts need to be linked to modeling efforts to understand fate and transport of dioxin in the environment. Innovative and cost-effective approaches to environmental remediation for application in Vietnam need to be developed, tested and applied. The environmental agencies of both countries strongly support the need for high quality research, development, and capacity building in these areas as a means to identify, characterize and
mitigate dioxin ecological impacts and bridge knowledge gaps regarding human exposure both in the past and into the future. Coordination between health and environmental efforts will be necessary to achieve success in the efforts described above.

Preliminary discussions have suggested two areas of research that should be further developed: ecological and restoration research on a degraded upland forest (such as the Ma Da forest) and research on the identification, characterization and remediation of hot spots (such as Da Nang Airport). Further discussions of this research should seriously consider and be guided by the recommendations of the environmental scientists involved in the consultative workshop held on March 7, 2002 (attached as Annex 2).

Other Activities for the Development of Joint Research Collaborations

Any joint research effort between Vietnamese and US scientists on the health and environmental effects of Agent Orange/dioxin requires the development of long-term collaborations between scientists in both countries. In order to strengthen these collaborations, the following activities are needed:

1.Support and encourage the exchange of graduate and post-graduate trainees.

2.Support and encourage extended visits of senior scientists from both countries.

3.Develop and implement seminar series and training programs to support collaborations.

4.Provide support as needed to implement scientific exchange.

Process for Funding and Guiding Research

Both sides agree that no additional proposals or research will be conducted under this Memorandum of Understanding until the following tasks are completed:

1.Establishment of a Vietnam-US Joint Advisory Committee to:

Define the scope of the joint research program; Coordinate the collaborative research program on human health and environmental effects of Agent Orange/Dioxin; and Review and approve research content areas under the program.

This coordinating body should have a support unit in each country and should meet at least once every year.

2.Development of regulations governing the organization and implementation of the collaborative research program in reference to and specification of relevant stipulations under the Agreement on Scientific and Technical Cooperation between the Government of the Socialist Republic of Vietnam and the Government of the United States of America and those under applicable laws in each country and international
practices. In addition, formal agreements on the following issues must also be developed:

The methods by which research proposals are developed, evaluated and funded;

The eligibility criteria for scientists wishing to be included in this research;

The applicable scientific and ethical policies to which the joint research must comply;

The methods for evaluating compliance with applicable laws, regulations and policies and the frequency in which compliance is reviewed;

The degree to which research findings will be made available to the international scientific community; and

The avenues through which research findings will be published and the process that must be followed for
publication approval.

3.Funding resources and funding mechanisms are established to ensure the success of the research effort. These include sufficient funding for the core research effort, for human resources development, and for laboratory facilities and equipment.

This document comprises one memorandum of understanding and three Annexes: 1) Agent Orange/Dioxin Research Gaps Workshop on Health Effects; 2) Agent Orange/Dioxin Research Gaps Workshop on Environment; 3) List of participants from discussions on March 7 and March 8.

Signed in Hanoi on the 10th day of March 2002.

Dr. Nguyen Ngoc Sinh
Director General
National Environmental Agency
Ministry of Science, Technology and Environment
For the Vietnamese side

Dr. Anne P. Sassaman
Director, Division of Extramural
Research and Training
National Institute of Environmental
Health Sciences
National Institutes of Health
Department of Health and Human Services
For the U. S. side


Hanoi, Vietnam, March 7, 2002
Recommendations from the Scientists' Workshop to the Organizing Committee On a Proposed Framework of Areas for Joint Activities

On March 7, 2002, a group of scientists from Vietnam, the US and other nations met to recommend research projects to the US and Vietnamese Governments. These recommendations are given below and represent the consensus opinion of the scientists present at the meeting. It does not necessarily
reflect the policy of either nation.


The session participants were reminded of the goals of the day's activity and the conclusions of the conference sessions conducted over the past three days. The joint statement was distributed to members for orientation.

Members of the session introduced themselves and indicated their expertise and interest in particular health effects areas. Topics of concern for research opportunities and gaps were then summarized. Based on this discussion, the members of the session agreed to focus their discussion and provide
recommendations to the Joint Organizing Committee in four specific areas:

Dissemination of existing data and findings between U.S. and Vietnam scientists Training programs to enhance collaboration between U.S. and Vietnam scientists Short term opportunities Long term opportunities

Dissemination of existing data and findings between U.S. and Vietnam scientists

Members of the session agreed that special effort to publish the proceedings of the meeting as well as the creation of data resources for all interested scientists should be given high priority. Of special concern was the translation and dissemination of materials prepared by Vietnam scientists for the 10/80 Committee and 33 Committee, as that material would be of interest to scientists both within Vietnam and in the U.S. Opportunities for publication exist within Environmental Health Perspectives as well as various web
site locations. Federal agencies may want to charge several of the organizing committee members with the development of an agenda for topics for rapid paper or web-based publication.

Training programs to enhance collaboration between U.S. and Vietnam scientists

There are differences in research practices, health data, health care systems and technology available for research in the U.S. and Vietnam. Because of these differences, it is essential to take advantage of existing and potential new training opportunities to enhance collaboration. The Fogarty International Program was cited as an example of an existing training mechanism which would allow for training
opportunities. Opportunities to have U.S. staff work through the Hanoi School of Public Health should be explored.Creating opportunities for the exchange of young scientists and providing training in a broad range of areas was emphasized.

Short term opportunities

The health session members agreed that these should be completed within a year or have achieved substantial progress within a year.

Institutional Review Board capability -- members agreed that an urgent priority should focus on the development of

Institutional Review Board (IRB) capabilities within the health centers of Vietnam to facilitate participation in
research opportunities and collaborations with U.S. investigators. While the process was not discussed
extensively, one potential mechanism may be to bring the National Institutes of Health (NIH) staff to Vietnam to conduct workshops on research ethics as established in the U.S. (taking those workshops as an opportunity to promote pairing of U.S. and Vietnam scientists to further facilitate collaborative possibilities).

Planning grants -- the members agreed that the Federal agencies from both governments should explore rapidly the development of planning grants. These grants would support an investigator from the U.S. and an investigator from Vietnam to establish a collaboration and begin feasibility studies and planning for a formal grant. Funds would support travel and communication for both investigators for a period of 24-36 months while they develop a formal grant application to the U.S.

National Institutes of Health.

Principles for interactions and collaboration -- there is a need to develop guiding principles for interactions between U.S. and Vietnamese investigators.

Criteria for site selection for population studies -- while there is a clear interest in hot spots (i.e., highly
contaminated areas), they should not be the only sites of interest, and guiding criteria for evaluation of proposed sites need to be developed jointly by the U.S. and Vietnamese governments.

Yearly scientific meetings for collaborators and potential collaborators -- select relevant themes to highlight beyond presentation of research results (e.g., IRB issues, research design issues).

Long term opportunities

Birth cohort study -- similar to that being conducted in Denmark and planned in the U.S. Health effects surveillance systems which allow GIS and spatial disease monitoring, modeling and tracking. Clinical trials which include prevention research. Research linking health and environmental research. Development of collaborative population research based on appropriate disease categories; endometriosis, trophoblastic disease, neural tube defects. Enhance vital records systems -- birth registration, death certificates, census data, etc.


Hanoi, Vietnam, March 7, 2002

Recommendations from the Scientists' Workshop to the Organizing Committee On a Proposed Framework of Areas for Joint Activities

On March 7, 2002, a group of scientists from Vietnam, the U.S. and other nations met to recommend research projects to the U.S. and Vietnamese Governments. These recommendations are given below and represent the consensus opinion of the scientists present at the meeting. It does not necessarily reflect the policy of either nation.

Recommendations from the group:

Joint environmental research activities of the U.S. and Vietnam should include, as appropriate, aspects of the following research areas:

Analytical research, including research into detection and assessment of "hot spots," areas of high contamination. Fate and transport studies to estimate potential routes of exposure and assist in characterizing risk. Remediation studies to develop optimal technologies for removing hazardous contaminants. Ecosystem restoration research, focusing initially on upland forests but eventually including mangroves and aquatic ecosystems. All these ecological/environmental research activities will be
supported by appropriate capacity building, including scientific information transfer, information technology,
equipment, training (especially of young investigators), and support for collaborations.

Vietnamese scientists proposed the use of two model demonstration sites for research activities: Da Nang airport and Ma Da forest. These sites are proposed both because of their usefulness as models of the environmental effects and because they are more easily accessible than other affected sites are. The environmental effects at these two sites are very different, as noted below. The U.S. scientists endorsed
the idea of demonstration sites but said they would defer to the Vietnamese scientists for the choice of the specific sites.

Da Nang airport is an example of a highly exposed area. It was used as a military base during the war. There are many people living nearby whose water supply is compromised by hazardous contamination. Vietnamese scientists would suggest collaboration on projects to assess and remediate an area near Da Nang airport as a model for how such technologies could work. The most highly contaminated portion of the
site, which will be the focus of decontamination activities, is about one hectare. Note: Da Nang airport is currently being used as a commercial airport, so research activities would have to be conducted around ongoing commercial activity. Vietnamese authorities will have to be consulted to make sure activities on the contaminated area are kept separated from any human contact. The contaminated area is close by the airport, but it is isolated from it.

Ma Da is an example of a degraded upland forest. The site is located near Ho Chi Minh City. This demonstration site would be used to test ecosystem restoration strategies as opposed to remediation of contamination, since the forest is not at this time very much contaminated. The problem with this site
is ecosystem impact from deforestation rather than residual chemical contamination. Many attempts at restoration have been made which have not met with success. It is difficult to restore inland areas in which the soil has been degraded.

In addition, there was discussion of focusing research on the impacts of defoliation on the mangroves and how best to effect their recovery. There are concerns about the mangroves because they are a semi-aquatic system. They are also very important for the overall ecology. These are not, however, the first priority for the Vietnamese scientists. They might be selected as a third priority area if resources permit.

Research Plan for Da Nang site

The ultimate objective for the research and workplan for the Da Nang site is a feasible level of decontamination side-by-side with research on decontamination/remediation technologies, on fate and transport of dioxins, and on effects on flora and fauna in the area.

Analytical research: Investigation of different ways to measure dioxin and other chemical components of herbicides and their metabolites is needed.

Da Nang demonstration project will need site characterization to help select correct approaches for
remediation. Criteria for decontamination will need to be established.

Fate and transport: The effects of the patterns of water flow through this site during rainy season will necessitate studies of fate and transport of dioxin and other contaminants into streams and rivers. Ecological impacts, including impacts on biodiversity, should be evaluated.

Remediation research: Remediation technology research projects will need to be developed for Da Nang. It is critically important that trained personnel be made available to carry out this work to avoid injury to workers. The remediation and site characterization should be conducted along the most stringent guidelines, training and equipment for protection of workers.

In addition, many people live near the Da Nang site. It may be possible to coordinate research on human health effects of Agent Orange/dioxin with environmental research at this site.

Research Plan for Ma Da site

The ultimate objective for the research and workplan for the Ma Da site is restoration of the deforested area to a state that will promote the development of a tropical forest ecosystem.

Analytical research: Ma Da demonstration project will have a need for site characterization.

Ecosystem research: A two-pronged approach was proposed. This would include side-by-side efforts to do research projects on small areas and to attempt actual restoration at the same time on larger adjacent areas. The Dong Nai river ecosystem is also important to consider in planning ecosystem research on the Ma Da forest. In Ma Da forest, restoration has been initiated, but there is a question about whether the appropriate species have been used.

There are issues about ecosystem restoration in terms of what will be feasible. Many deforested sites have been invaded by grass and bamboo, which are impervious to herbicides. Burning the vegetation presents its own environmental problems. This issue will require careful consideration. It may be that an intermediate type of restoration could be the focus for initial efforts, rather than attempting to reconstruct the original ecosystem. Research on ecological succession is needed.

If resources are available, it is important for these two research projects to go forward in parallel, with
coordination and collaboration where necessary. There were no other known constraints that would prevent the two projects going forward together.

An interdisciplinary program was proposed as a model for joint activities. Such a program would support research teams focusing on analytical activities, fate and transport studies, development of remediation technologies, etc. Specific parts of the projects would focus on providing training and instrumentation. It was also recommended that studies take into account the needs and activities of health scientists and epidemiologists in order to ensure that health effects research and environmental research is optimally coordinated.


March 7, 2002 Discussion, Workshop on Health

U.S. Participants

1.Dr. Thomas Sinks, Centers for Disease Control and Prevention
2.Dr. Allan Smith, University of California, Berkeley
3.Dr. David Carpenter, State University of New York, Albany
4.Dr. Lutz Edler, German Cancer Research Center
5.Dr. Irva Hertz-Piccioto, University of California, Davis
6.Dr. Drue Barrett, Centers for Disease Control and Prevention
7.Dr. Michael Linnan, Health Attache, U.S. Embassy to Hanoi
8.Dr. Brenda Eskenazi, University of California, Berkeley
9.Dr. Paolo Toniolo, New York University
10.Dr. Long Ngo, Harvard University
11.Dr. Donald Mattison, Columbia University School of Public Health

Vietnamese Participants

1.Prof. Hoang Dinh Cau, Former Chairman of 10/80 Committee
2.Prof. Bui Dai, Former Director of Hospital 108
3.Prof. Phan Thi Phi Phi, Hanoi Medical College
4.Prof. Trinh Van Bao, Hanoi Medical College
5.Dr. Nguyen Thi Ngoc Phuong, Director, Tu Du Hospital
6.Prof. Nguyen Van Nguyen, Army Academy
7.Prof. Truong Dinh Kiet, Institute of Medicine and Pharmacology, Ho Chi Minh City
8.Prof. Le Bach Quang, Army Academy
9.Dr. Nguyen Phu Thang, Polio Clinic, Hue Province
10.Dr. Chu Quoc Truong, Army Academy

March 7, 2002 Discussion, Workshop on Environment

U.S. Participants

1.Dr. Vance Fong, U.S. Environmental Protection Agency
2.Dr. Arthur Galston, Yale University
3.Dr. John Geisy, Michigan State University
4.Dr. Sheila Newton, National Institute of Environmental Health Sciences
5.Dr. Dennis Paustenbach, Exponent, Inc.
6.Dr. M. B. Ray, National University of Singapore
7.Mr. Gary Sigmon, U.S. Embassy, Hanoi
8.Dr. Jeanne Stellman, Columbia University
9.Dr. William Suk, National Institute of Environmental Health Sciences
10.Dr. William Farland, U.S. Environmental Protection Agency

Vietnamese Participants

1.Prof. Dang Vu Minh, National Center for Natural Science and Technology
2.Prof. Vo Quy, Vietnam National Institute
3.Prof. Dang Huy Huynh, Environmental Resources Protection Association
4.Prof. Tran Xuan Thu, Joint Vietnam-Russian Tropical Center
5.Prof. Chu Pham Ngoc Son, Analytical Environmental Service Center
6.Prof. Nguyen Duc Hue, Hanoi National Institute
7.Dr. Nguyen Van Minh, Environmental Treatment Center
8.Dr. Dang Thi Cam Ha, National Center for Natural Science and Technology
9.Eng. Phung Tuu Boi, forest Investment and Planning Institute

March 8, 2002 Discussion

U.S. Delegation

1.Dr. Anne Sassaman, National Institute of Environmental Sciences
2.Dr. Christopher Portier, National Institute of Environmental Sciences
3.Dr. William Farland, U.S. Environmental Protection Agency
4.Dr. Drue Barrett, Centers for Disease Control and Prevention
5.Mr. Gary Sigmon, U.S. Embassy, Hanoi
6.Dr. Joel Michalek, Department of Defense
7.Dr. Larry Needham, Centers for Disease Control and Prevention
8.Dr. Michael Linnan, Health Attache, U.S. Embassy, Hanoi
9.Mrs. Sandra Lange, National Institute of Environmental Sciences
10.Dr. Sheila Newton, National Institute of Environmental Sciences
11.Dr. Thomas Sinks, Centers for Disease Control and Prevention
12.Mr. Vance Fong, U.S. Environmental Protection Agency
13.Dr. William Suk, National Institute of Environmental Sciences

Vietnamese Delegation

1.Dr. Nguyen Van Tuong, Ministry of Health
2.Dr. Nguyen Ngoc Sinh, Ministry of Science, Technology and Environment
3.Prof. Trinh Van Bao, Ministry of Health
4.Eng. Phung Tuu Boi, Ministry of Agriculture and Rural Development
5.Dr. Nguyen Tien Dung, Ministry of Science, Technology and Environment
6.Dr. Dang Thi Cam Ha, National Center for Natural Science and Technology
7.Dr. Tran Manh Hung, Ministry of Health
8.Prof. Phan Thi Phi Phi, Ministry of Health
9.Dr. Vo Quy, Hanoi University


I - The chemical used during the Vietnam War:

1-Historical background:

During the Vietnam War, in addition to conventional weapons, the United States military used toxic chemicals to spray large areas of southern Vietnam, as well as part of Laos and Cambodia. The use of chemicals in this  war began in 1961 and was halted by the US in 1971. However, forces of the regime in Saigon continued to use these chemicals until 1975. Although many toxic substances were employed, the most common were herbicides and defoliants.
In 1937-1938, US chemical makers discovered a new variety of herbicide, which could mimic plant hormones, causing plants to wither or shed their leaves (hence, the term defoliant). These chemicals were initially thought to have no harmful effect on the environment.
Two chemicals  2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (Trichlorophenosyacetic acid), became widely accepted in agriculture from 1940 onwards. During the 1950s and 1960s, herbicides these two chemicals contributed to the "green revolution" which saw great increase in agricultural production throughout the world. Today, 2.4-D is still used in agriculture (although recent research suggests it may be linked with cancer).

However, 2.4.5-T has been banned in the US and a number of other countries during the 1970s as research began to link this chemical with mutations in experimental animals. The 2.4.5-T used in these experiments were discovered to contain impurities belonging to a class of compounds known as dioxins, which we now know to be both highly toxic and end environmentally persistent. A form of 2.4.5-T with much reduced dioxin content is still used in agriculture and forestry in some North European countries.
During the First World War (1914-1918), the war which involved the greatest use of chemicals in mankind history took place. As many as 100 million kg of toxic chemicals were used as weapons. Recognizing the terrible effects of toxic chemicals even on non-combatants the League of Nations promulgated a convention in 1924 banning the use of noxious substances in wartime, many countries have signed this convention.
The US Defense Department studied the use of herbicides and defoliants in the early 1960s, conducting experiments on the chemicals and research on aerial spraying techniques in the US and Thailand as well as southeast Asian battlefields. The US military began using herbicides in the South Vietnam battlefield in 1961.
In the early period, between 1961-65, herbicides were used only around military bases, artillery positions and along roadsides. When the war reached its peak between 1966-1970, toxic chemicals were sprayed from the air over a wide area of southern Vietnam and expanded to Laos and Cambodia.
The herbicide/defoliant campaign was aimed at the following major goals:

To protect US and allied military bases from attack by clearing grass
         and shrubs and defoliating trees.

   To destroy foliage in order to discover hidden military positions, stores and transport routes, thus facilitating air and artillery strikes.

 To destroy crops thought useful to guerilla forces; typically local residents were restricted to 'strategic hamlets' in order to limit contact with guerillas.

In the early period of the chemical war, WE aircraft with Saigon regime markings and Western pilots in civilian clothes conducted aerial spraying operations. The chemical spraying campaign was code-named: "Operation Ranch Hand".

2. Chemical substances used during the Vietnam Conflict

Herbicides and defoliants

These chemicals have different mixtures with names such as Agent Purple, Agent Orange I and II, Agent Green, Agent Blue, Agent White, Agent Pink, Dinoxon, Trinoxon, Triquat and so on. Agent Orange, Agent Green, Agent White... are only military codes, marked by a band of color paint of that color on the storage drums to facilitate identification in store rooms. These names do not refer to the color of the chemical in the drum.

Volume of sprayed chemicals-Kinds and time

Opinions differ on the volume of chemicals used. The US Defense Department official account is 17,585,778 gallons (66,650,086 liters). Other reports put the volume at 72 million litters, of which 44 million liters were Agent Orange. Table 1 shows the breakdown of chemicals used by year, volume and area in hectares.

Table 1

Principal chemicals deployed by US forces

Year of spraying (estimate)
Volume of spray (106 kg)
Area of spraying (106 ha)
Percentage of total sprayed area
Agent Orange
Agent White
Agent Blue
Note: Agents Orange, Agent White, Agent Blue and Malathion were mainly sprayed by C-123 planes, while CS was sprayed by helicopters. Malathion was used to control mosquitoes. CS is commonly known as tear gas.

Table 2 shows the volume of Agents Orange, White and Blue sprayed each year between 1991 and 1971.

Table 2

Herbicides used during the Vietnam War
Volume sprayed annually (cubic metre=103 litters)

Agent Orange
Agent White
Agent Blue

Dioxin and related compounds

On theory, herbicides would degrade within weeks or months after spraying in natural environment. However, among herbicides sprayed in Vietnam, Agent Orange and other chemicals based on 2,4,5-T contain dioxin, which is stable and highly toxic.
The most toxic of the dioxin family is 2,3,7,8-TCDD (Tetrachloro Dibenzo-p-Dioxin), also called TCDD.

It is claimed that dioxin (2,3,7,8-TCDD) is  highly toxic, "the most toxic chemical discovered by mankind so far". Dosages of a few millionths of gram per kg body weight have been known to kill experimental animals. Some scientists estimate that the population of New York could all die if a mere 80 g of TCDD were put city's water supply.

At present, it is thought that the half-life of TCDD in soil is about 15 years or longer, while its half-life in human body the time is estimated at between 5 and 8 years. However, in a number of low-level creatures (shrimps, fish) its half-life is estimated to be about one month.

Dioxin can be produced in a variety of industrial settings. For this reason, dioxins have attracted the interests of scientists for over 20 years. Since 1981, international seminars on dioxin and its related compounds have been held virtually every year.

It is difficult to estimate the amount of dioxin in Agent Orange. Sources have estimated figures between less than 0.1 per million and more than 60 ppm, with an average of 3 ppm. Roughly, a total of 170-kg of dioxin was sprayed in South Vietnam throughout the war.

Environmental released dioxin contaminates the human body in three ways:

-     The most important is through food, and to a lesser extent, drink.
-     The second way if via the respiratory tract: experiments on animals show that 92 per cent of dioxin pumped into the respiratory tract penetrates body tissues.
-     The third is trough skin, which is in direct contact a contaminated chemical or dioxin-contaminated soil. However, the absorption of dioxin through skin is low.

It is believed that between 85-90 percent of a body's dioxin burden comes from contaminated food. As dioxin is poorly soluble in water, contamination through drinking is very small.

Environmental dioxin probably enters the human in the following way. after an area is sprayed, dioxin reaches the ground. Some of it sticks to organic substances in soil, other more is carried by water to rivers and lakes, sinking into the bottom mud, and contaminating fish such as catfish or eel and invertebrates such as shrimp, which in turn can contaminate humans.

In 1970's, Italian scientists conducted research on the possibility of dioxin contamination through food crops (rice, wheat, corn, bean and fruits). They cultivated food crops in experimental fields using fertilizers with a high content of dioxin. They and came to the conclusion that dioxin does not convert into the final products of the plant. Hence, crops grown on dioxin contaminated soil do not contain dioxin. However, if dioxin-contaminated soil sticks to these products, people or animals eat them will be contaminated with dioxin. In some Northern European countries, cattle living near chemical factories, which emitted dioxins, became contaminated by ingesting contaminated grass.


Foods, which can contain dioxin, are mainly shrimps, fish, meat and milk. Foods such as grains, rice, fruits do not contain dioxin.

After entering the human body, dioxin is absorb through the gastro-intestinal tract and enters the blood circulation. Dioxin first concentrates in the liver, fat, skin and muscle tissues, but then is gradually accumulates in fat tissues. This is because dioxin is soluble in fat. Dioxin is eliminated from of the body through bile, but since bile is re-absorbed by the intestines its elimination from the body is very slow.

In pregnant women, dioxin can go to the foetus through the placenta. After birth, dioxin can be eliminated through the mother's milk, but the toxin then enters the nursing child. Dioxin can be found in the eggs of chickens, ducks and other birds.


According to the Forest Survey and Planning Institute (Vietnam Ministry of Agriculture and Food Industry), the total acreage of forests sprayed with chemicals was 3,104,000 ha, (17.8 percent of South Vietnam's natural acreage). Of this, 95 percent was inland forests (2,954,000 ha) and 5 percent coastal mangrove forest (150,000 ha).

This caused a great ecological imbalance, destroying timber, wild animals and forest products. The seed source of the forest was debilitated, making it that much harder to restore natural forest. Without cover to retain water, flooding in the rainy season and drought in the dry season, adversely affected agricultural production. Topsoil washed away, making it far easier for the land to become exhausted and lateritlized, still further hindering forest recovery. While the uplands became eroded, the lowlands became choked with sediment, still further increasing the threat of flood.


Dioxin can be analyzed to study on the aftermath of Agent Orange deployment, in surveying its effects in contaminated areas, and in determining the role of dioxin on human health.

However, it is not easy to test for dioxin residues in Vietnam. Dioxin testing today is precise, requiring costly modern equipment. Even developed countries have only a few laboratories, which can perform these tests. At present, the World Health Organization has certified only about ten laboratories worldwide as capable of analyzing dioxins. This is one reason the cost of a dioxin test is very high.

A few Vietnamese laboratories are able to conduct some dioxin testing, but the cost is also high, between 7-9 million Vietnamese dong per test.

Collecting and preserving samples must be done under a strict protocol to prevent further chemical contamination. The sample container must be absolutely free of contamination. Organic samples (such as food, fat tissue, blood or milk) must be kept deep-frozen (-20 C) during transportation to the laboratory.

Thus, testing cannot be done conducted widely. Testing is not yet done for clinical diagnosis, either in Vietnam or in developed countries.

So far, most dioxin testing is done abroad to ensure the impartiality and scientific accuracy.

Nearly 30 years have elapsed since the use of these chemicals ended. So general dioxin levels in general are lower both in the environment and human tissues in comparison with wartime.

In 1980, Professor Ton That Tung was the first Vietnamese scientist to collaborate with Dutch scientists in dioxin testing on soil from Rung Sat area (of Ho Chi Minh City). In 1984, international cooperation was extended, first with US scientists (A. Schecter), and then with scientists from France, Japan and Canada. To date, about 4,000 samples of variety materials have been tested at eight laboratories in the Netherlands, Germany, France, Japan, Canada and the US. Test results have been reported in seminars within and outside Vietnam, and published widely in Vietnamese and foreign languages.

These are the results of the testing in brief.

1. Dioxin level in Soil and River Mud:

In several areas examined, (excluding former chemical stores, airports, sea ports), no alarmingly high levels of dioxin were found. (The US Environment Protection Agency sets alarming detoxification level at over 1 ppb (1,000 ppt). (Chart 1)

With only some hundreds of samples taken from such a wide area of Southern Vietnam, that conclusion has yet to be confirmed.

2. Dioxins level in Food:

In 1973, fish and shrimp tested for dioxins often had shockingly high levels of dioxins. Those tested from 1986 to now were found to have much lower levels (chart 2-3).

Research conducted by Schecter and Furst to compare dioxin levels in food from Vietnam, Russia and Germany showed that until 1990, the dioxin level in commonly-used food in Vietnam is not higher than food in other countries  (chart 4).

Research by Prof. Dr. Le Cao Dai shows that in comparison with the tolerable daily intake of World Health Organization standard (10 pg /kg body weight/ day).(chart 5).  

-     Food collected in 1973, and tested at Harvard University suggest the daily intake would have been between 40 and 235 times the permissible level of dioxins set by the World Health Organization;
-     In 1986-1990, this level decreased by about one tenth and one Thirty-fifth

3. Dioxin level in Human tissues:

Not until 1984 did we have conditions to conduct systematic tests for dioxins in human tissue (fat, blood and breast milk) in people living in sprayed areas and non-sprayed areas.

These tests show:

a. In fat tissue (chart 6-7):

Only 12% of the samples taken in areas of Northern Vietnam, which was not effected by chemicals, tested positive of dioxins with average strength of 1.7 ppt.

As many as 83.3% of the samples taken in Southern Vietnam where chemical spraying operations took place prove positive for dioxins, with average strength of as high as 17 ppt.

Thus, the dioxin level in fat tissue of people living in sprayed areas in Southern Vietnam is higher than people who lived in non sprayed areas.

Chart 7 shows dioxin level in Vietnam (sprayed and non-sprayed areas) compared with industrialized countries (USA, Canada, Japan,). Dioxin levels in sprayed areas of Southern Vietnam is ten fold higher than those in the North and two or three fold higher than industrialized countries.

b. In breast milk of nursing mothers

Breast milk taken from nursing mothers living in sprayed-areas (Tan Uyen - Song Be, Can Gio - Saigon in Southern Vietnam) was tested for dioxins for the first time in 1970 (Baughmann - Messelson-Harvard University). Three years later, in 1973, the same group returned to the same places to repeat the sampling.

In the 1970 study, dioxin levels in breast milk were very high, averaging 484ppt with some samples reaching 1,450ppt, the highest level recorded in the world. The 1973 research found that although dioxin levels in breast milk of nursing mothers had decreased, averaging 131ppt, ranging from  

Similar research was conducted in 1986, showed that dioxin levels decreased remarkably compared to 1973, ranging between 7 and 20ppt. However, breast milk from the South still had from three to six times higher dioxin levels than samples taken in the North (average 1.8-2ppt).

Results of a survey conducted by the World Health Organization in 1988 comparing levels of dioxins in breast milk of nursing mothers worldwide are shown in chart 9. These data indicate that dioxin levels in breast milk in other countries is 2-3ppt, in Hanoi 2.2ppt, but in Ho Chi Minh City 7ppt, and in Song Be province 17ppt. Nursing mothers from Agent Orange-sprayed areas have higher levels of dioxin in milk than women in Hanoi (non-sprayed area) and industrial countries.

c. In veterans from the North:

During the second Indochina war, many young Northerners including soldiers, volunteers and administrative officials participated to the war in the South and where also exposed to Herbicides. Tests for dioxins in fat tissue and blood were conducted among ex-soldiers study the long-lasting effects of the chemicals.

Results of these tests, shown in chart 10-11, indicate that the dioxin burden of ex-soldiers who were in the Southern battlefields is much higher than the people who lived permanently in the North.

In conclusion, tests for dioxins in soil and food conducted since 1986 indicates that the level of dioxins in the environment and human tissues decreased over time. Dioxins in commonly used food returned to normal and level in once contaminated soil is not so high.

In other hand, people who were exposed to Agent Orange, people who lived in sprayed-areas and Northerners who served in the South during the war still have higher levels of dioxin than people who lived in non-sprayed areas in Northern provinces.

Most worthy of note is the level of dioxins in breast milk of nursing mothers. The high level of dioxins in breast milk spreads contamination from mothers to children.


1. Studies by US scientists:

Bitter dispute lasted for years on the consequences of Agent Orange on US Vietnam war veteran. Veterans pressured the US government to study the aftermath of Agent Orange. A US Air Force study begun in 1979 was suppressed more than 15 years or where published, figures were altered. While independent research accumulated information on the harmful effects and thousands of veterans and their families complained of health problems. Their claims became a class-action compensation suit against chemical companies.

In the late 1980s, an Admiral E. Zumwalt a retired high-ranking US officer, participated to the discussion and contributed to clarification of the problems. Zumwalt commanded US forces during the Vietnam War and ordered the use of Agent Orange along canals in Southern provinces to protect US naval forces from guerrilla attack. His son was also in the military and fought in Vietnam. After the seeing death of his son from cancer and the disability of his grandson believed to be linked to Agent Orange exposure, he asked the US Congress and the American Academy of Sciences to reconsider previous studies.

In 1994 and 1996, the Institute of Medicine under the American Academy of Sciences officially admitted that there was evidence linking the following 10 diseases Agent Orange exposure. Four diseases were stated to have sufficient evidence and six having “limited evidence”.

a. Diseases with sufficient evidence of a link with exposure to herbicides:

- Soft tissue sarcoma
- Non-Hodgkin's lymphoma;
- Hodgkin's disease; and
- Chloracne.

b. Diseases having limited evidence to of a link with exposure to herbicides:

- Respiratory cancers (including cancers of the lung, larynx, trachea and bronchus);
- Prostate cancer;
- Multiple Myeloma;
- Peripheral neuropathy (acute or subacute);
- Spina bifida; and
- Porphyria Cutanea Tarda.

2. Studies done in Vietnam:

Vietnamese scientists have conducted many studies on the long lasting effects of chemicals on human health. Those studies suggested that in people exposed to Herbicides compared to non-exposure people have:

-     An increase rate of primary liver cancer and oropharynx cancer. Several abnormality of pregnancy such as:
-     Miscarriage;
-     Still birth, premature-birth;
-     Hyditiform mole and choriocarcinoma
-     High rates of birth defects, especially neural tube defects including  
anencephalia, microcephalia, hydrocephalia, spina bifida, cerebral palsy  

Congenital malformations could occur successively in several children of the  same family. There is evidence that there exists a second generation of disabled children, grandchildren of veterans who served in southern battlefields.

There is an increase rate of infant mortality, particularly in the years right after the war.  This is believed to be associated with the higher level of dioxins in breast milk of nursing mothers at that time.

Many other health conditions seem to be linked to Agent Orange exposure :
-     Loss of appetite, insomnia, weight loss, fatigue, headache, impaired vision or hearing;
-     Hepatitis, liver cirrhosis;
-     Immune-deficiency: increase rate of infectious diseases and malaria;
-     Intestinal diseases, gastric ulcer, gastroduodenitis;
-     Chloracne and skin diseases, dermatitis
-     Arteriolosclerosis, hypertension and cerebral circulation disorders.

3. Number of Agent Orange victims:

Surveys on Agent Orange victims have not been carried out nationwide until December, 1998. Through pilot surveys, the number could be estimated at between 800,000 and one million nationwide. In addition, there are from 70,000-100,000 children born deformed as a result of Agent Orange exposure. These numbers will, however, change with every passing day as older victims die and new victims are added to the list.

The Standard to Identify Agent Orange victims

A standard to identify Agent Orange victims is necessary in order to provide relief to Agent Orange victims, within the Government policy to give preferential treatment to them.  Based on domestic and foreign studies, propose the following two main criteria to categorize the victims of Agent Orange:

-     Criterion of exposure to Agent Orange during the war;
-     Criterion of pathology: suffering from one or more diseases believed to be associated with Agent Orange.

a. Criterion on exposure to Agent Orange during the war:

+ To Northerners (from Quang Binh province northwards):
War veterans, young volunteers, and administrative officials who served in the south during the war (from 1961-1975) are considered to be exposed to Agent Orange. Those people who operated in extensively sprayed areas (see the map) during the 1966-1970 period are listed in the high-risk group.

+ To Southerners:
All people who lived in Southern Vietnam (from Quang Tri province southwards) from 1961-1975 are believed to be exposed to Agent Orange. The number of people who lived in extensively-sprayed areas (see the map) during the 1966-1970 period are considered to be directly sprayed and listed in the high-risk group.

b. Pathological problems due to Agent Orange exposure:

1. Cancers:
Liver cancer
Soft tissue sarcoma
Non-Hodgkin's lymphoma
Hodgkin's disease
Respiratory cancers (including cancers of the lung, larynx, trachea and bronchus)
Prostate cancer

2. Metabolic disorders:
Lipid: cerebro-vascular, coronary artery disease.
Glucoid diabetes.

3. Neuoraphy
Peripheral neuropathy (acute or subacute)
Multiple myeloma

4. Skin diseases
Porphyria cutanea tarda

5. Reproductive problems
Still birth
Hyditoform moles, choriocarcinoma
Birth defects in the first and second generation.


1-Scientific research:
Scientific research should be continued, in order to fully investigate the long term harmful effects of the chemicals used in war on the environment and human health and learn the most appropriate measures for overcoming them.
On the environment

-     Identify the places of inland and mangrove forest currently destroyed by the chemicals. Because these places belong to different provinces of southern Vietnam with different conditions of altitude, microclimate, geology, local habits, any reforestation program should be appropriate to each area if it is to be successful
-     Complete the dioxin analysis in soil of "hot spots" (areas suspected of being highly contaminated with dioxin: former American airbases, chemical warehouses, sea ports, places of chemical flux due to accidents during the spraying operation (there were 48 similar places during Operation Ranch Hand) in each place, sampling should be done at different depths.
-     Conducting clean up operations in areas polluted with over 1000 ppt, dioxin in soil.
-     Besides herbicides, we should also consider the environmental consequences of the irritant chemical (tear gas, CS). Investigation should be made to identify where CS containers were dropped in southern Vietnam forests and determine the best way to destroy them.
On human health:
Numerous research projects could be done to make clear more deeply the effects of dioxin on human health. Research should focus on the following problems:
-     Pathology linked to Agent orange/dioxin exposure
-     Specific measures for prevention and treatment those pathology
-     Persistence of dioxin on humans and the environment
-     Investigation throughout the country on the total number of Agent Orange victims

2-Solving the effects of the chemical war on the environment:

-     The only way to recover the environment is to replant the destroyed forests, Former studies show that such operations can be successful, even in heavily spayed areas, But it requires a considerable funding.
-     Several methods can be proposed to clean up dioxin in highly contaminated areas (if such areas still exist). The best method is to burn the soil at high temperature. But such operations require specialized technology.
3- Solving the harmful effects on human health:

      Several measures must be taken in order to minimize the harmful effect of chemicals on humans:

Disseminating knowledge on the chemicals war, their effects on health,
    Preventative measures and measures for the early detecting illnesses.
Educating the population about hygiene and disease prevention.
Implementing family planning, abolishing superstitious beliefs including
    Discrimination against malformed children.
Regular health control for early detection of diseases especially for
    people in high risk groups.
-     Victims of Agent Orange need help for the treatment of their illnesses, and support to improve their living standards which are, in general, lower social assistance than average.
-     Malformed children must be categorized in according to the nature of  their disease in order to receive special care.
-     Surgical treatment and functional rehabilitation
-     Special education and professional training
-     The community, and especially the government, should allow the victims certain privileges such as disability compensation and heath insurance
-  Special schools for malformed children and priority in getting suitable

 Press Release Nov 4, 2002

Washington, Nov. 4 (Bloomberg) -- Dow Chemical Co. and Monsanto Co. will get a U.S. Supreme Court hearing as they seek to head off a new round of lawsuits by Vietnam veterans exposed to Agent Orange, a defoliant used by the military and later linked to cancer.

The justices agreed to hear an appeal by the chemical companies in a case that may buttress the ability of businesses to resolve group personal injury claims through a single nationwide settlement.

Dow, Monsanto and 11 other companies say two men seeking to sue them are bound by a 1984 settlement that was designed to resolve all claims by veterans against the makers of Agent Orange for $180 million. A federal appeals court permitted a suit by Daniel Stephenson and Joe Isaacson, who developed cancer after the 1994 deadline for seeking payments from the settlement fund.

The lower court ruling ``undermines the legal peace that petitioners paid $180 million to secure,'' the companies said! in their appeal.

Stephenson and Isaacson say their interests weren't adequately represented in the negotiations that led to the 1984 agreement. The settlement was designed to resolve all claims on behalf of the 2.5 million veterans who served in Vietnam from 1961 to 1972.

The 2nd U.S. Circuit Court of Appeals in New York, citing two recent Supreme Court decisions limiting class-action settlements, ruled 3-0 that Stephenson and Isaacson could press ahead with their suit.

The companies ``would like to be done and say, `You get nothing,' but I don't think our system of justice allows that,'' said Isaacson's attorney, Gerson H. Smoger.

Lawyers on both sides of the case said they don't know how many other Vietnam veterans might become eligible to sue under the 2nd Circuit's reasoning.

Dow's shares rose 9 cents to $26.57 at 10:22 a.m. in New York Stock Exchange composite trading, while Monsanto's shares rose 15 cents to $17.00.

Chemical Shower

The lawsuit is the latest chapter in a long-running legal and medical battle over Agent Orange, a powerful plant-killer that contained dioxin and was showered onto the jungle, and U.S. soldiers, during the Vietnam War.

Dow and Monsanto produced about two-thirds of the Agent Orange used during the conflict, Smoger said.

Other defendants in the case include units of Occidental Petroleum Corp., Valero Energy Corp., YPF SA and Koninklijke Philips Electronics NV.

At the Supreme Court, Dow and Monsanto argue that the lawsuit seeks to reopen issues that had been resolved by the courts almost two decades ago. The companies say both a federal trial judge and an appeals court concluded that the settlement was a good deal for veterans because they weren't likely to win had their cases gone to trial.

Dow, based in Midland, Michigan, and St. Louis-based Monsanto argue that the 2nd Circuit ruling, if allowed to stand, would raise new que! stions about hundreds of other settlements. Asbestos settlements would be especially vulnerable because people exposed to the fiber may not show signs of illness for decades, said Seth Waxman, the lawyer for Dow and Monsanto at the high court.

``The fear is that nothing is ever going to be over in these contexts,'' Waxman said.

Vietnam Service

The justices will hear arguments next year and rule by the end of June.

Stephenson served in Vietnam from 1965 to 1970 on the ground and as a helicopter pilot. He was diagnosed in 1998 with multiple myeloma, a bone marrow cancer.

Isaacson, who served in Vietnam in 1968 and 1969, worked at an Air Force base for planes that sprayed Agent Orange. He was diagnosed in 1996 with non-Hodgkin's lymphoma.

Dow and Monsanto already are facing other legal battles. A West Virginia jury concluded Oct. 24 that Dow's Union Carbide unit is legally responsible for thousands of asbestos-related deaths and i! llnesses, while Monsanto may face chemical cleanup costs related to its 1997 spinoff of Solutia Inc.

The case is Dow Chemical v. Stephenson, 02-271.