Agent Orange Exposure & Blood Cancer Risk
Last updated: April 2023
Agent Orange is a chemical that was used during the 1960s and early 1970s as part of war efforts in Vietnam, Laos, and the Korean demilitarized zone. It was sprayed by the U.S. military in order to destroy crops and forest cover and to clear vegetation that surrounded U.S. bases.1
In the process, roughly 1.5 million troops and many civilians were exposed to the chemical.
Decades after its use ended, questions still linger about Agent Orange and whether it causes chronic lymphocytic leukemia (CLL), among other blood cancers and long-lasting health problems.2
What is Agent Orange?
Agent Orange is a type of defoliant called a phenoxy herbicide. It came in drums identified by a bright orange stripe around the container (hence the name). Agent Orange was an equal mixture of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).1
Agent Orange also contained small amounts of chemicals known as dioxins, which are recognized by health organizations worldwide to be human carcinogens (cancer causing). The most common dioxin found in Agent Orange was also one of the most toxic to humans, 2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD.1
Millions of gallons of Agent Orange were used during the Vietnam War.
In the early 1970s, research revealed that Agent Orange and similar herbicides caused birth defects in lab animals. Around the same time, soldiers coming home from Vietnam began blaming a constellation of health problems on the chemicals, including skin rashes, cancer, psychological problems, birth defects in their children and more. The military stopped using Agent Orange in 1971.1
Linking Agent Orange, CLL, and other blood cancers
Despite decades of research, we still don’t have definite answers about whether Agent Orange causes CLL.
Several U.S. federal and state government institutions, plus Australia, Germany, Italy and Vietnam, have followed the long-term health of Vietnam veterans, factory workers and farmers exposed to this class of chemicals. They’ve looked at possible links between Agent Orange (or dioxin) and a number of cancer types.1
A 2002 report from the Health and Medicine Division (HMD) (formally known as the Institute of Medicine) of the National Academy of Sciences, Engineering, and Medicine reviewed the research up to that point and found sufficient evidence of an association between exposure to herbicides and chronic lymphocytic leukemia. 3
In 2008, the HMD added hairy cell leukemia and other chronic B-cell leukemias to its findings.4
Then, in 2014, the report was updated again to say that CLL, soft tissue sarcomas, non-Hodgkin lymphoma, and Hodgkin lymphoma were all associated with Agent Orange exposure. There is less evidence that respiratory cancers (lung, bronchus, trachea, larynx), prostate cancer, multiple myeloma, and bladder cancer are associated with exposure to these chemicals.5
These findings mean that veterans and their families were eligible for a host of health care and survivor benefits due to their exposure to Agent Orange.
But, it still didn’t answer the question of whether Agent Orange directly causes CLL. This research only said that exposure to it during the Vietnam War has been linked to a slightly increased risk of developing CLL and other cancers.6
CLL is the most common form of leukemia in adults and usually appears in older adults, especially those over age 60, thus long after they left military service. It is more common in men than women, and whites more than other ethnic groups.
Its symptoms include persistent fatigue, weakness, frequent infections that are otherwise unexplained, weight loss, swollen lymph nodes, enlarged liver or spleen, bleeding or bruising more easily, and bone pain or tenderness.
If you’re a veteran with CLL or other associated blood cancer
The Veteran’s Administration recommends those who think they may have been exposed to Agent Orange to get cancer screening tests and contact their doctor immediately if they experience any symptoms.
Veterans may also join the Agent Orange Registry to get tested and learn more about the benefits related to exposure.
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