Agent Orange was one of several 'rainbow herbicides' used by the U.S. military to defoliate forests and destroy crops during the Vietnam War. Between 1961 and 1971, under Operation Ranch Hand, aircraft sprayed roughly 19 million gallons of herbicides over South Vietnam; Agent Orange accounted for the largest share, on the order of 11 to 12 million gallons. Its dioxin contaminant, TCDD, was an unintended byproduct of manufacturing.
The consequences outlasted the war by decades. Dioxin persists in soil and sediment at former storage and spray sites, and exposure has been associated with cancers, neurological disease, heart disease, diabetes, and birth defects. Cleanup at major hot spots such as Da Nang has proceeded with U.S. funding in recent years, while debates over compensation and responsibility — the debates that motivated projects like the one once hosted here — remain unresolved.