A boy flashes the peace sign while practicing how to write the Vietnamese alphabet at a center for children affected by dioxin exposure in the village of Hoa Nhon, near Da Nang, Vietnam.The Da Nang Association of Victims of Agent Orange/Dioxin says that more than 1,400 children around the city suffer from mental and physical disabilities because of dioxin exposure, a legacy of the U.S. military's use of Agent Orange and other herbicides during the Vietnam War more than 40 years ago. About 60 children attend the Hoa Nhon center each day. Many of them have mental disabilities, while others cannot hear or speak. It usually takes a new child about a year to learn how to interact with other children, says Phan Thanh Tien, the association's president. Staff members try to teach the children to read and write, sew clothes, make handicrafts and help their families raise crops and livestock. Children who cannot hear or speak are taught sign language. The Vietnam Red Cross estimates that 3 million Vietnamese suffer from illnesses related to dioxin exposure, including at least 150,000 people born with severe birth defects since the end of the war. The U.S. government is paying to clean up dioxin-contaminated soil at the Da Nang airport, which served as a major U.S. base during the conflict. But the U.S. government still denies that dioxin is to blame for widespread health problems in Vietnam and has never provided any money specifically to help the country's Agent Orange victims. May 29, 2012.