According to a decision announced on Oct. 13, US veterans of the Vietnam war who were exposed to AO and have subsequently contracted diseases such as B cell leukemia, Parkinson's and ischemic heart diseases will be considered for government welfare.

The decision raises the total number of categories of patients to enjoy benefits for exposure to AO to 15.

As a result, some 200,000 US Vietnam veterans are estimated to benefit from the welfare. The Department said more than 2 million US veterans were exposed to the toxic from January 1965 to April 1970.

In the past US veterans exposed to AO have sued the US chemical companies that produced and sold the toxic chemical to the US government.

Their complaints were resolved outside of court, with some plaintiffs paid several thousands USD each. After that, they won their case and received an annuity of US$1.52 billion in total.

Meanwhile, Vietnamese AO victims have not yet received any compensation from US chemical companies as the US court dismissed their lawsuit.

According to data provided by US scientists, between 1961 and 1970, the US army sprayed some 80 million litres of toxic chemicals, containing more than 300kg of dioxin, in South Vietnam.

Consequently, around 4.8 million Vietnamese people were exposed to the deadly toxic chemical and some 1.4 billion ha of land and forests, 12 percent of Vietnam, were covered in the toxin.