For the first time, a study shows the sharp increase in prostate, skin and other types of cancer – a conclusion drawn from a statistical study of US veterans who sprayed toxic chemical dioxins during the war.

Between 1965 and 1970, US forces used more than 19 million gallons of Agent Orange over the forests of southern Vietnam in an attempt to expose enemy troops – with devastating health effects on hundreds of thousands of Vietnamese and thousands of US troops.

The director of the National Protection Fund for Agent Orange Victims, Le Ke Son, said only 10% of those people disabled by the herbicide were recognised as victims of the chemical agent.

"Incomplete statistics show that there are over one million victims of the dioxin nationwide, including second and third generation victims," Son said.

The latest study analysised data gathered over the past two decades - information collected for the Air Force Health Study on Operation Ranch Hand.

Dangerous exposure

The research suggests that Vietnamese and veterans with the highest exposure to dioxin were more than twice as likely to develop cancer "at any anatomical site" than unexposed veterans who were in southeast Asia for two years or less.

"Incomplete statistics show that there are over 1 million victims of the dioxin nationwide, including second and third generation victims"

Le Ke Son, 
director, National Protection Fund for Agent Orange Victims

The Ranch Hand veterans' risk of contracting prostate cancer was more than six times greater than that of the other veterans, while their risk of melanoma, a type of skin cancer, was more than seven and a half times greater, the study found.

But Joel Michalek, an author of the analysis, cautioned that there was less statistical confidence in the figures for prostate cancer and melanoma because they were based on a small number of cases.

The analysis will be published in the February edition of the Journal of Occupational and Environmental Medicine.