Hanoi says the defoliant, which was used by US forces during their Southeast Asian folly to strip trees and plants of vegetation and deny North Vietnamese troops cover, continues to have devastating health consequences.

Washington, on the other hand, argues that there is not enough evidence to link the spraying of millions of litres of Agent Orange to generations of birth defects and other diseases, as claimed by its former enemy.

Agreeing to disagree, both governments signed a memorandum of understanding in March last year on a framework for more research into the impact of the defoliant.

To date, despite the best attempts by academics on both sides of the Pacific, the MOU has neither funded nor helped any studies in Vietnam. However, privately-funded research initiatives have taken place.

One such study, released last week and published in the August issue of the Journal of Occupational and Environmental Medicine, found that Agent Orange continues to contaminate people through their food consumption.

"Although the spraying ended over three decades ago, in certain areas of Vietnam, food is clearly a present-day route of intake of dioxin from Agent Orange, as it might have been since the spraying began in 1962," it said.

The project, conducted last year by scientists from the United States, Germany and Vietnam and led by Dr Arnold Schecter of the University of Texas School of Public Health, a veteran Agent Orange researcher, analysed dioxin levels in 16 food samples taken from Bien Hoa City.

Bien Hoa, some 30 kilometres (20 miles) north of Saigon -- later renamed Ho Chi Minh City -- and once home to a sprawling US air force base where Agent Orange was stored, is considered a dioxin "hot spot," one of several in southern Vietnam.

Over the past five years, the blood dioxin levels of 43 residents of Bien Hoa were extensively tested. Approximately 95 percent of blood samples were found to have elevated levels of TCDD.

TCDD, the most toxic of chlorinated dioxins, is a by-product from the manufacture of Agent Orange, and can cause an increase risk of cancers, immune deficiencies, reproductive and developmental changes, nervous system problems and other health effects.

"Clearly, food, including duck, chicken, some fish and a toad, appears responsible for elevated TCDD levels in residents of Bien Hoa City, even though the original contamination occurred 30-40 years before sampling," the report said.

The US embassy in Hanoi declined to comment on the study.

Not surprisingly, the Vietnamese government has touted the findings as a validation of its own research.

"We support this survey which has revealed findings similar to our own conclusions," said Dr Tran Manh Hung, chairman of the national committee set up to examine the consequences of chemical warfare in Vietnam.

"According to our studies, the level of danger from Agent Orange is still very serious in Vietnam."

But Schecter injects an element of caution into the debate, saying more credible research needs to be done into Hanoi's claims that Agent Orange has resulted in congenital malformations and liver cancer.

"It will take careful and slow high quality research by Vietnamese scientists, who know their country, and Western scientists, who are ahead in methodologies of health research, working without government -- US or Vietnam -- interference to answer questions about the causes of malformations and cancers in Vietnam," Schecter told AFP.

According to an April report by New York's Columbia University, between 1961 and 1971, the US military sprayed 77 million litres of Agent Orange, whose name derived from the orange bands on the drums containing the product.

Although Hanoi has not asked directly for compensation, it has long sought financial damages from Washington for the victims of the herbicide, which it says currently number around one million people.

In the United States, some 7,500 Vietnam veterans have already won the right to monthly compensation payments for diseases linked to Agent Orange.

Over 58,000 Americans and around three million Vietnamese died during the war, which ended in April 1975 with fall of Saigon.

The two antagonists established diplomatic relations in 1995 and five years later signed their landmark trade pact.

WAR.WIRE