Agent Orange and cancer
Agent Orange is a herbicide mixture that was predominantly used by the United States during the Vietnam War to eliminate forest cover and control weeds. It is composed of two herbicides, 2,4-D and 2,4,5-T, the latter of which is associated with a hazardous by-product known as TCDD or dioxin, classified as a human carcinogen. Exposure to Agent Orange has been linked to several types of cancer, including soft-tissue sarcoma, non-Hodgkin lymphoma, and chronic lymphocytic leukemia, among others. Individuals who served in Vietnam, as well as civilians and workers exposed to the chemical, are considered at risk. The health implications of Agent Orange exposure have been studied primarily in populations that faced significant exposure to dioxin, revealing potential health impacts that extend to the children of affected individuals. Although the U.S. military ceased the use of Agent Orange in 1970 due to concerns about its effects, numerous lawsuits have been filed by veterans seeking justice for health issues linked to their exposure. As a result, the United States has imposed a permanent ban on the use of 2,4,5-T and Agent Orange. This history reflects both the environmental consequences of warfare and the ongoing health challenges faced by those affected.
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Agent Orange and cancer
DEFINITION: Agent Orange was a chemical mixture used in the United States to control weeds and in Vietnam during the Vietnam War to remove forest cover. So named because of the orange stripes painted on its storage drums, Agent Orange is a blend of two herbicides: 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Although 2,4,5-T is not highly poisonous, the manufacturing process generates a toxic by-product called TCDD, or 2,3,7,8-tetrachlorodibenzo-p-dioxin. This dioxin, classified as a human carcinogen, tainted Agent Orange formulations.
ALSO KNOWN AS: Super Orange
RELATED CANCERS: Soft-tissue sarcoma, non-Hodgkin lymphoma, Hodgkin disease, chronic lymphocytic leukemia (CLL), acute myelogenous leukemia (AML)
Exposure routes: Inhalation, ingestion, skin contact, ocular absorption
Where found: Herbicide mixtures formerly used for agricultural, forestry, and military purposes
At risk: Combatants and civilians exposed to Agent Orange during the Vietnam War and their children, workers occupationally exposed to the chemical, and populations exposed through domestic herbicide spraying. Anyone who served on a Navy or Coast Guard vessel in the Vietnam-adjacent waterways between 1962 and 1975 is believed to have been exposed to Agent Orange.
Etiology and symptoms of associated cancers: Because epidemiologic data on Vietnam veterans is limited, the health effects of Agent Orange have been studied indirectly in certain populations highly exposed to dioxin or dioxin-tainted herbicides. These studies provide sufficient evidence linking Agent Orange to chloracne, an acne-like skin disorder, and to certain cancers induced when TCDD activates a protein receptor in target cells. Soft-tissue sarcomas develop from fat, muscle, or deep body tissues and usually appear as lumps. Hodgkin disease (highly curable) and non-Hodgkin lymphoma originate in lymphatic tissue, resulting in painless swelling of under the skin. Chronic lymphocytic leukemia, which develops from white blood cells, is often asymptomatic, but later is marked by enlarged lymph nodes. Agent Orange has been linked, with limitations, to a small increase in bladder cancer, as well as multiple myeloma, prostate cancer, sarcomas, and respiratory cancers, according to the National Academy of Medicine (NAM; formerly the Institute of Medicine).
Paternal exposure to Agent Orange may be associated with acute myelogenous leukemia in children. This fast-growing cancer of the bone marrow produces abnormal white blood cells and results in fatigue, shortness of breath, and increased susceptibility to infection. Skin cancer, kidney cancer, and male breast cancer are among other cancers that have been studied among those exposed to Agent Orange and similar herbicides but that the NAM has classified as having insufficient evidence of association.
History: Phenoxy herbicides, including the 2,4,5-T component of Agent Orange, were developed in the 1940s and widely used in agriculture and forestry. Starting in 1960, during the Vietnam War, the United States military sprayed Agent Orange onto lands in Vietnam and Laos. It suspended this activity in 1970 after a study in laboratory animals linked 2,4,5-T to birth defects. Since the 1980s, various groups of Vietnam veterans have filed lawsuits against the makers of Agent Orange. The United States has permanently banned all uses of 2,4,5-T and, consequently, Agent Orange.
Bibliography
“Agent Orange and Cancer Risk.” American Cancer Society, 13 Feb. 2023, www.cancer.org/cancer/risk-prevention/chemicals/agent-orange-and-cancer.html. Accessed 17 June 2024.
Haberman, Clyde. “Agent Orange's Long Legacy, for Vietnam and Veterans.” The New York Times, 11 May 2014, www.nytimes.com/2014/05/12/us/agent-oranges-long-legacy-for-vietnam-and-veterans.html. Accessed 17 June 2024.
Institute of Medicine, Board on the Health of Select Populations. Veterans and Agent Orange: Update 2012. National Academies P, 2012.
“Veterans' Diseases Associated with Agent Orange.” VA Public Health, 24 Jan. 2024, www.publichealth.va.gov/exposures/agentorange/conditions/index.asp. Accessed 17 June 2024.
Waskey, Andrew Jackson. "Agent Orange." Encyclopedia of the Veteran in America. Ed. William A. Pencak. ABC-CLIO, 2009, pp. 28–32.
Williams, Stephen B., et al. "Exposure to Agent Orange and Risk of Bladder Cancer Among US Veterans." JAMA Network Open, vol. 6, no. 6, 2023, doi.org/10.1001/jamanetworkopen.2023.20593. Accessed 17 June 2024.