HANOI -- Thirty-five years after US forces stopped spraying Agent Orange in Vietnam, Vietnamese who were exposed to the defoliant are about to have their day in court.
From 1961 to 1971, the US military sprayed more than 20 million gallons of Agent Orange and other herbicides over South Vietnam to deprive communist forces of food and forest cover. The herbicides were contaminated with poisonous dioxin. Vietnam says millions of its citizens have suffered diseases and birth defects as a result.
Last year, 27 Vietnamese filed a class-action suit against the chemicals' manufacturers,
It is the first Agent Orange suit filed by Vietnamese. Hearings will begin tomorrow in the US District Court's Second Circuit in Brooklyn.
The chemical companies have moved to dismiss the case, saying US law bars suits against corporations for work they carry out under government contracts. The Vietnamese plaintiffs argue this immunity does not protect companies when their products are dangerously defective, as Agent Orange was.
''The companies knew that their sloppy manufacturing processes caused Agent Orange to contain high levels of dioxin," said Jonathan Moore, one of the plaintiffs' American lawyers. ''They ignored it, because they figured the only people getting sprayed were 'the enemy.' "
The plaintiffs also argue that spraying Agent Orange was a war crime, since international law prohibits the use of chemical weapons. The defendants say this claim is baseless.
''Agent Orange was a defoliant, used to protect US and South Vietnamese troops," said Scott Wheeler, a spokesman for Dow Chemical. ''In no way was it ever used as a weapon."
The companies say that, contrary to the plaintiffs' claims, dioxin in the trace amounts in which it was present in Agent Orange has never been shown to cause disease in humans. Moreover, because the US government was well aware of the herbicides' dioxin levels, the manufacturers say, the government-contractor defense protects them. They say any settlement with Vietnamese victims should result from negotiation between the US and Vietnamese governments, not from litigation against the manufacturers.
Last month, the US government filed a statement supporting the chemical companies. It argued that the court has no authority to judge ''the validity of the president's decisions regarding combat tactics and weaponry," including Agent Orange.
For Nguyen Thang Son, such legal questions are beside the point. Son, 55, served with the North Vietnamese Army in the border region between North and South from 1965 to 1972, fighting in the bitter battles for control of the A Luoi Valley and the town of Khe Sanh in 1968. He was exposed to Agent Orange ''too many times to remember," he said in a recent interview at his home in Hanoi.
''The Americans would spray it out of planes," Son said. ''One day you might inhale it several times. The next day once; the next day two or three times."
Today, Son says he experiences stomach troubles, difficulty breathing, and headaches. His two children suffer even more. His daughter Nguyen Phuong Tui is epileptic, blind, and deaf. At 29, she has the physique of a 10-year-old, and is unable to speak or move by herself.
His son Nguyen Thang Tung, 25, is blind. A graduate of Hanoi's Conservatory of Music, Tung is an accomplished player of a traditional single-stringed instrument called the dan bau and performs regularly on national television.
But his father worries about his future. ''No girl dares marry him," said Son, for fear his children will also suffer birth defects. ''That's my greatest sorrow."
No one knows how many Vietnamese have been exposed to dioxin from American-sprayed herbicides. A recent government-commissioned study by the Institute of Medicine, an arm of the National Academy of Science, found that at least 2.1 million Vietnamese had been directly sprayed.
Dioxin also persists in the environment and in the food chain. Studies of Agent Orange ''hot spots" find elevated levels decades after the spraying stopped, particularly in meat and fish. A joint US-Vietnamese study of the A Luoi Valley in Vietnam's central highlands, where Son fought, found dioxin levels in some breast milk dozens of times higher than maximum levels recommended by the World Health Organization. Birth defects in local villages were 1½ to 4 times more frequent than they had been before the war.
Dow Chemical and Monsanto maintain that decades of study have failed to show Agent Orange caused health problems.
''The overwhelming weight of scientific evidence says there's no link between Agent Orange and serious human illness," said Monsanto spokesman Glynn Young.
The Institute of Medicine, however, says there is strong evidence that exposure to herbicides is associated with five serious diseases, including Hodgkin's disease and a form of leukemia. It says there is ''suggestive" evidence that herbicides might cause birth defects and cancer.
While the manufacturers have never acknowledged Agent Orange causes disease, they reached a $180 million settlement in 1984 with US veterans exposed to the herbicide. The last payments under that scheme were made in 1997. Vietnamese were not eligible.
The scientific questions will not be at issue tomorrow. The relevant legal questions are whether the defendants are indemnified as government contractors, and whether the statute of limitations has expired. Under the US Alien Tort Claims Act, plaintiffs have 10 years to file their cases. The Vietnamese say they were unable to file claims in US courts until 1994, when Washington lifted its trade embargo on Vietnam.