The worst dioxin-contaminated site in Vietnam is Bien Hoa airbase, which is 30 miles north of Ho Chi Minh City, after President Nixon ordered the U.S. military to stop spraying Agent Orange in 1970, this is the site where all the Agent Orange barrels remaining in Vietnam were collected. The barrels were processed and shipped to Johnston Island in the Pacific Ocean, where they were incinerated at sea in 1977.