Thursday, February 6, 2014

Agent Orange and Cancer
About 3 million Americans served in the armed forces in Vietnam and nearby areas during the 1960s and early 1970s, the time of the Vietnam War. During that time, the military used large amounts of mixtures known as defoliants, which are chemicals that cause the leaves to fall off plants. One of these defoliants was Agent Orange, and some troops were exposed to it. Many years later, questions remain about the lasting health effects of those exposures, including increases in cancer risk.

This article offers a brief overview of the link between Agent Orange and cancer. It does not offer a complete review of all evidence – it is meant to be a brief summary. It also includes some information on benefits for which Vietnam veterans exposed to Agent Orange may be eligible.
During the Vietnam War, US military forces sprayed millions of gallons of herbicides (plant-killing chemicals) on lands in Vietnam, Laos, and other nearby areas to remove forest cover, destroy crops, and clear vegetation from the perimeters of US bases. This effort, known as Operation Ranch Hand, lasted from 1962 to 1971.

Different mixes of herbicides were used, but most were mixtures of 2 chemicals that were phenoxy herbicides:

  • 2,4-dichlorophenoxyacetic acid (2,4-D)
  • 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)
Each mixture was shipped in a chemical drum marked with an identifying colored stripe. The most widely used mixture contained equal parts 2,4-D and 2,4,5-T. Because this herbicide came in drums with orange stripes, it was called Agent Orange. Today, Agent Orange refers generally to all the phenoxy herbicides sprayed at the time. (Other types of herbicides were also used, including cacodylic acid and picloram.)

The 2,4,5-T in Agent Orange was contaminated with small amounts of dioxins, which were created unintentionally during the manufacturing process. Dioxins are a family of dozens of related chemicals. They can form during the making of paper and in some other industrial processes. The main dioxin in Agent Orange, 2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD, is one of the most toxic.

After a study in 1970 found that 2,4,5-T could cause birth defects in lab animals, the use of 2,4,5-T in Vietnam was stopped. A year later, all military herbicide use in Vietnam ended. During the 1970s, some veterans returning from Vietnam began to report skin rashes, cancer, psychological symptoms, birth defects in their children, and other health problems. Some veterans were concerned that Agent Orange exposure might have contributed to these problems. These concerns eventually led to a series of scientific studies, health care programs, and compensation programs directed to the exposed veterans.

A large class-action lawsuit was filed in 1979 against the herbicide manufacturers, and was settled out of court in 1984. It resulted in the Agent Orange Settlement Fund, which distributed nearly $200 million to veterans between 1988 and 1996.

Although there is now quite a bit of evidence about the health effects of Agent Orange, many questions have not yet been answered.

No comments:

Post a Comment