A Vietnamese worker jumps from a mound of construction material at the site of a former American airbase in Danang, Vietnam on Wednesday, April 24, 2013. The U.S. government is paying for a cleanup at the airbase, which was used during the Vietnam War to store Agent Orange defoliant since linked to illnesses and disabilities among Vietnamese. [Photo: Hau Dinh/Imagine China]
Fifty years after US warplanes first sprayed a chemical weapon, known as Agent Orange, on Vietnam's jungles to destroy enemy cover, the US is helping clean up one of the most contaminated sites - Danang airport.
The airport, which once served as one of America's major air-bases, has been referred to as a dioxin "hotspot" due to the high concentration of toxicity in the soil and sediment there.
During the Vietnam War (1962-71) the US military dumped an estimated 75 million litres of Agent Orange and other herbicides on about a quarter of former South Vietnam - decimating around 20234 square kilometres (5 million acres) of forest.
Dioxin has been linked to cancer, birth defects and other disabilities.
Part of the contaminated site consists of a dry field where US troops used to store and mix the defoliant before it was loaded onto planes.
The area also includes lakes and wetlands where dioxin has seeped into the soil and sediment over the decades.
The site is only separated from busy residential communities by a high concrete wall.
But now, by the side of the tarmac of Vietnam's third busiest airport, a square concrete structure has been built, measuring 70 metres (230 feet) by 100 metres (328 feet).
There, around 73 thousand cubic metres (2578 cubic feet) of contaminated soil and sediment will be placed for treatment, before being returned back to the airport grounds.
The "thermal desorption" treatment, which is being used in this 84 million US dollar remediation joint project, is said to be the most effective and scientifically proven method for destroying dioxin.
In the pile structure, excavated soil and sediment will be heated up to between 750 and 800 degrees Celsius (1382 and 1472 Fahrenheit).
At that temperature, dioxin will be broken down into harmless substances, primarily carbon dioxin and water.
It is expected that 95 per cent of the dioxin will be destroyed through the heating process while any vaporised dioxin will be vacuumed out and captured in a secondary treatment system.
This will ensure that no dioxin and other contaminants are released into the environment.
The project is expected to be completed by 2016. 1 2