Pentagon officials said Friday that a preliminary investigation had found dioxin contamination at Fort A.P. Hill, Va., where 32,000 Boy Scouts camped during a national jamboree in 1981.

The Pentagon, however, said the dioxin -- one of the most toxic chemicals known to man -- did not pose a health hazard because the nearest Boy Scout encampment was 150 feet away from the contamination.

An Army spokeswoman, Maj. Mary Andrews, said Pat Hillier, assistant secretary of the Army for installations and logistics, and other military officials met Friday with representatives of the Boy Scouts of America to discuss the situation.

"At that meeting, Mr. Hillier stated that the Boy Scouts did not camp in areas of known contamination. Since the area of contamination was so small, levels so low and length of time the scouts were there so short, preliminary findings indicate that the residual contamination is not great enough to pose a health hazard," Andrews said.

She said a small shed adjacent to the Boy Scout encampment had been used to store Silvex, a weed-killer containing "very low levels of dioxin."

In Denver, Dr. Barry Rumack, director of the Rocky Mountain Poison Center, expressed concern Friday about possible hazards posed by the dioxin contamination during the 1981 jamboree.

"Dioxin is probably one of the most toxic chemicals known in the world," Rumack said. He said the substance can cause cancer and is mutagenic, capable of causing abnormalities in fetuses.

Rumack said all of those exposed should be examined and monitored by doctors for several years.

The Army statement issued by Andrews said that during the 1981 jamboree, some "staff personnel" were billeted near the shed where the weed-killer was stored.

"They were housed in Army tents equipped with plywood flooring as well as cots, so primary contact with the ground in this area was minimal. The nearest campsite used by scout youths was 150 feet away from the area of contamination," the spokeswoman said.