Scientists reveal that the us military bombarded Vietnam with greater quantities of Agent Orange and other defoliants than previously estimated. The findings were unearthed by a study spanning five years, conducted by us -based Columbia University's environmental health specialists. It also discloses that the defoliant sprays contained higher amounts of carcinogenic dioxins than formerly thought.

The Columbia group studied records of spraying operations in Vietnam to determine the types of defoliant used in particular missions. They estimate that 77 million litres of Agent Orange were sprayed, and not 70 million litres as recorded before.

The most important finding was the amount of dioxins used. Project head Jeanne Stellman thinks that twice the quantity of dioxins was sprayed than previously calculated. "Millions of Vietnamese were likely to have been sprayed upon directly,' the report concludes.

Other studies have revealed that some Vietnamese harbour up to 200 times the average amount of dioxins in their bodies. The report is likely to ratchet up pressure on the us to conduct further research on veterans exposed to the defoliants and from Vietnam for damages.