© Jan Banning / Panos Pictures..Between 1961 and 1971, US troops sprayed 72 million litres of herbicides over ± 10% of the surface of South Vietnam - 51 million of this was Agent Orange, containing a total of 170 kilos of 2,3,7,8-T4CDD (dioxin)..Laboratory tests led to the conclusion that dioxin can lead to birth defects and genetic damage in animals. Vietnamese and other researchers found higher rates of congenitally malformed babies among people who have been sprayed with this defoliant..Cam Lo district (Quang Tri province) just south of the former North-South border is one of the heavily sprayed areas..Ho Van Thach (boy, 10), here with his sister Ho Thi Thiet (6), mother Dang Thi Kim Yen (34) and father Ho Van Thanh (36) is a possible victim. The father: "Thach can't recognize anything. His legs and arms can move, he can't speak. When he feels hungry, he cries. His eyes look normal. For all personal activities he needs help. He can't sit in bed.".Both grandfathers were soldiers in the South-Vietnamese army. In the early '80's Thanh worked in a forest "where all the trees were burned; no leaves, only branches". They live in Cam Lo town.