The Vietnam War, which lasted 30 years and left 4m Vietnamese and 58,000 US troops dead, came to an end 40 years ago today with the fall of Saigon

Tan Tri does not know a thing about Agent Orange. But doctors say he lives with its effects every day, when he crawls off his wooden bed and waits for someone to feed him. He is 25.

His mother Vo Thi Nham was exposed to Agent Orange when US forces showered the chemical across swathes of Vietnam half a century ago to the destroy jungle cover of its wartime enemy.

Nham believes it’s the reason her son was born physically and mentally disabled.

“Other people around here were affected by Agent Orange, too, but it was really bad for us,” Nham said at her home in Danang, central Vietnam. “At least they can walk – he can’t.”

Tri, slumped on the concrete floor at her feet, chimed in.

“I can walk with my arms!”, he said, correcting her.

The Vietnam War ended 40 years ago today and its memory is fading among its young population. But Agent Orange is the enduring legacy it cannot forget, with children of a second post-war generation still being born with deformities which their doctors believe are linked to the defoliant.

Today, deformities are visible everywhere. In the streets, beggars carry children with swollen heads or unnaturally bent limbs. Bodies are twisted, some are born without eyes

Some three million Vietnamese have suffered from fatal diseases, disabilities and illness after coming into contact with Agent Orange, according to the Vietnam Association of Victims of Agent Orange/Dioxin (VAVA).

Today, deformities are visible everywhere. In the streets, beggars carry children with swollen heads or unnaturally bent limbs. Bodies are twisted, some are born without eyes.

A Reuters journalist this month travelled from north to south Vietnam and documented lives of many disabled people whose relatives doctors say were exposed to Agent Orange.

One former soldier, Do Duc Diu, said he buried 12 of his 15 children after they died as infants. He has graves prepared for two daughters who are sick and may not live long.

Nguyen Thi Van Long (right) and her best friend Dinh Thi Huong, who is deaf and mute, spend time together at Friendship village, a hospice for Agent Orange victims outside Hanoi. The fathers of both girls were soldiers who were exposed to the the chemical during the Vietnam War and health officials link the girls’ health conditions to the defoliant. Some 120 children and 60 Vietnamese veterans stay at Friendship village, which was established in 1998. Photo: Damir Sagolj/Reuters

Le Dang Ngoc Hung, 15, lies taciturn on a bamboo mat most of the day, his listless eyes and mouth drooping. Hung cannot walk and has the delicate skin of a newborn because he rarely ventures outside.

“It was sad,” his mother, Le Thi Thao, said recalling when she discovered his disability. “But he is my son, so of course, I have to take care of him.”

Agent Orange is complex, its long-term impact much debated and subject to legal cases by Vietnam and American veterans. US studies have found heightened risks of prostrate, lymphocytic leukaemia and melanoma in exposed servicemen, but similarly with the impact of dioxin on post-war generations of Vietnamese, research indicating strong links has also cited complexities in making conclusive determinations.

The US is fast becoming an important ally for Vietnam, but Agent Orange remains a source of friction.

Washington allocated $43 million in 2012 to clean land contaminated by dioxin from the estimated 20 million gallons of Agent Orange sprayed in Vietnam from 1962-1971, but many Vietnamese say that’s not enough.

Some American veterans are sympathetic, like Chuck Palazzo, who has devoted years of his life to working with Vietnamese to fight the stubborn vestiges of Agent Orange.

But he’s unsure if they’re winning the battle.

“Does it get better or does it get worse?” he said. “It’s a grind. And you have to keep at it. We just have no idea how long this is going to last.”