The Fate of Agent Blue, the Arsenic Based Herbicide, Used in South Vietnam during the Vietnam War

• 作者: Kenneth R. Olson Larry Cihacek
• 来源期刊: 土壤科学期刊(英文)
• 学科: 农学
• 关键词: Ansul Chemical Company Arthur W. Galston ARSENIC As Food Crops Groundwater Marinette WISCONSIN Menominee MICHIGAN Menominee River Rice Rice Paddies Rainbow Herbicides Mekong Delta
• 年，卷（期）: 2020,（11）
• 页码范围: 518-577
• 页数: 60页
• 分类号: S51

摘要

The destruction of the South Vietnamese rice (<em>Oryza sativa L</em>) crop using an arsenic-based herbicide known as Agent Blue during the American Vietnam War (1965-1972) was not a secret;however, it received little media attention in the United States. Republic of Vietnam and United States (U.S.) militaries began destroying food crops (rice) in November of 1962 primarily via aerial applications in the Mekong Delta and Central Highlands of South Vietnam. Spraying of Agent Blue on 100,000 ha of mangrove forests and about 300,000 ha of rice paddies just before rice harvest time resulted in the destruction of the standing crop and rendered the land contaminated with arsenic (As). Six Rainbow herbicides, commonly called Agent Orange, Agent Green, Agent Pink, Agent Purple, Agent White, and Agent Blue, were sprayed on wetlands, rice paddies, forests, mangroves, bamboo and military base perimeter fences to defoliate jungle vegetation, reveal guerilla hiding places and destroy the food supply of enemy troops. South Vietnamese farmers, U.S. and Republic of Vietnam military personnel, and communist insurgents were exposed to these herbicides with immediate and longer term impacts on personal health, civilian household food security and population-wide famine. Agent Blue (cacodylic acid, C₂H₂AsO₂,) was the most effective of all the Rainbow herbicides in killing rice and grasses. Manufacturing of cacodylic acid began in the late 1950s in the U.S. at the Ansul Company chemical plant in Marinette, Wisconsin and Menominee, Michigan. During the Vietnam War, ocean going ships were loaded with 208-liter Agent Blue barrels and shipped via the St. Lawrence Seaway to the coast of South Vietnam. Arsenic (As) is a naturally occurring element that is found throughout SE Asia deltas including the Mekong Delta. Today arsenic contaminated rice and groundwater are growing concerns as neither naturally occurring arsenic nor anthropic arsenic have a half-life and cannot be destroyed. Anthropic arsenic has re