A senior Vietnamese health official called yesterday for normal diplomatic and trade ties between Washington and Hanoi, and suggested that the continuing outflow of refugees could be controlled or halted if the continuing outflow of refugees could be controlled or halted if the United States would supply aid to Vietnam.

Dr. Ton That Tung, national director of science and health for Vietnam, made the statements in an interview with editors of The Washington Post. Tung, on a five-week U.S. visit sponsored by the American Friends Service Committee, also represents the former imperial capital of Hue in the Vietnamese National Assembly. He is among the highest officials of the Hanoi regime to visit here.

A cancer specialist who has published research on the effects of chemical defoliants used by the United States in Vietnam, Tung said the medical effects of the war are still being felt. High incidences of miscarriages, birth defects and liver cancer, he said, are all believed to have been caused by defoliants.

According to Tung, half of all infants born with birth defects in one hospital in Vietnam are anancephalic-born with no upper portion of the brain. That defect, he said, is normally found in about one percent of the infants born with congenital defects.

Tung said there are no controls, and no pre-war statistics, with which to compare the present situation. But villagers in the countryside, he said, are reporting the births of many more deformed infants, and many more miscarriages than they are accustomed to.

Concerning refugees, Tung attributed the exodus of about 85,000 "boat people" from Vietnam last year - a flow which is continuing to other Southeast Asian countries - to poor economic conditions caused by war and to propaganda from Peking. He said ethnic Chinese had been warned by Peking that they would be killed if they remained in Vietnem.

"If you will help us economically, we will stop it," Tung said of the exodus. "Our economy was destroyed by the war. You fought the war. The destroyed economy is the reason they are leaving."

Tung likened the flow from Vietnam to the emigration from Ireland in the 1840s due to the potato famine.

For many months after the fall of Saigon in the spring of 1975, the Hanoi government insisted that the United States agree to reconstruction aid as a prior condition of normal diplomatic relations. By the time Vietnam dropped the condition last year, the Carter administration was unwilling to move ahead.

Since last November, the United States has taken the view that Vietnam's invasion of Cambodia, its increasingly close relations with the Soviet Union and the plight of the "boat people" refugees must be taken into account in discussing diplomatic relations. No active Washington-Hanoi discussions at the official level are taking place at present.