US Air Force records indicate that at least 6542 fumigation missions were conducted during the Ranch Hand operation. By 1971, 12 percent of the total area of South Vietnam had been sprayed with defoliant chemicals, at an average concentration of 13 times the recommended application rate for use by the US Department of Agriculture. Only in South Vietnam, it is estimated that 10 million hectares of agricultural land were finally destroyed. In some areas, TCDD concentrations in soil and water were hundreds of times higher than levels considered safe by the United States Environmental Protection Agency. Altogether, more than 20% of the forests of South Vietnam were sprayed at least once during a period of nine years.
