The Human Health Impact of Agent Orange

Reproductive Impacts

The issue of whether or not Dioxin causes birth defects in humans is still debated. It is clear in animal studies that Dioxin causes birth defects in all species studied. The herbicide 2,4-D has also been shown to be teratogenic, causing birth defects, in animal studies. Scientists hesitate to extrapolate these animal studies to epidemiological studies on humans.   

The March of Dimes estimates that six percent of live births worldwide result in a child born with a major birth defect that is either genetic or partially genetic in nature, including those that may be caused by exposure to toxic chemicals. Some birth defects may not be evident until several years after the child’s birth.

Any understanding of birth defects, in order to be extrapolated in any meaningful way, require statistically significant quantities and the examination of a large exposed population. In addition, most epidemiological studies only focus on the offspring of exposed men, which produces less understanding about how Dioxin impacts reproduction outcomes in women. As a result, epidemiological studies on humans are challenging. 

Do Duc Diu, 58, tries to prevent daughter Do Thi Hang, 19, with congenital brain seizures, from injuring herself. Photo: Kuri Takashsashi, Chicago Tribune


For sure, ever since progress has been made in the studies of epigenetics, there has been increasing understanding about how chemicals, such as Dioxin, can influence how genes are signaled to turn on or off in order for certain functions to occur in fetal development. 

The U.S. National Academy of Sciences has reviewed the studies on the impacts of Dioxin and herbicides on birth defects and found inadequate or insufficient evidence of correlation between the two. It remains unclear if Dioxin can cause birth defects in exposed U.S. Veterans, other than spina bifida. Currently, spina bifida in children born to male veterans is the only recognized condition that is eligible for compensation by the VA. But in children of U.S. female veterans, there is an added layer of complexity.

The VA does recognize a wide range of birth defects as connected to their service, but do not attribute it to Agent Orange exposure, or Dioxin specifically. Female veterans have to prove that their child’s birth defects have no known cause and that they themselves have no family history of any such conditions in order to be eligible for benefits. With only approximately 8,000 female veterans, the number of children receiving support from the VA is very small. 

“Vietnam is home to a disproportionately large number of disabled children – including many affected by exposure to chemicals left over from the spraying of Agent Orange.”
– Frank Susa, U.S. Fund for UNICEF, 2008.

While the U.S. Institute of Medicine attributed only spina bifida and anencephaly to paternal exposure to Dioxin, Vietnamese researchers have been studying the impacts of Agent Orange since the war and have found an increased risk of abnormal birth outcomes, including infertility, miscarriages, stillbirths, and birth defects via both paternal and maternal exposure. Among the birth defects found were spina bifida, hydrocephaly, malformations of the extremities, musculature issues, developmental disabilities, congenital heart defects and cleft-palate. 

Vietnamese researchers have also found higher rates of birth defects in the grandchildren of the wartime exposed population.

Dang Hong Nhut overlooks the crib of young child with hydrocephalus in Bien Hoa. Mrs. Nhut was herself impacted by Agent Orange. She fought numerous cancers and had 3 miscarriages before a still birth in her 5th month of pregnancy. Her unborn son was severely disabled. She dedicated her life to helping children impacted by Agent Orange and died in 2018.

The conditions of these children are believed to be associated with their parent or grandparent’s exposure to Agent Orange-Dioxin during the war. Indeed in Viet Nam in the formerly sprayed regions and among veterans who served in the sprayed regions, there are high rates of children and young adults with mobility, speech and cognitive disabilities at varying levels of severity. Children who are unable to attend school are unemployable and in need of round-the-clock care. These affected populations face the greatest social and economic challenges.

As of 2018, UNICEF-Viet Nam estimated half a million children under 18 with disabilities live in Viet Nam. In general, there are higher rates of children believed to be affected by Agent Orange in the areas of the country that were more heavily sprayed and also in designated Dioxin hotspots.

Stills from “The Last Ghost of War” (2008), by dir. Janet Gardner. More information.

The Second Generation.
Photo: James Nachtwey