Dioxin is described by the Environmental Protection Agency as an unwanted, potentially deadly chemical byproduct that is sometimes produced in the process of making certain insecticides and herbicides. A colorless liquid, it can bond with soil and may be either inhaled by humans or absorbed through the skin, according to scientists.

It is broken down by soil bacteria and sunlight, a fact that has led critics to wonder whether the amount of dioxin present at A.P. Hill at the 1981 Boy Scouts jamboree was not significantly higher than the level shown by soil tests this year.

Scientific data on health problems associated with dioxin is not yet complete, and yesterday national and regional health officials debated the best course of action for worried parents.

A skin rash known as chloracne as well as tissue cancers and bladder and liver disorders have been associated with dioxin, but not in great enough numbers to establish a statistical link, scientists said.

Symptoms may occur from three to 10 weeks after exposure, according to physicians at the regional Rocky Mountain Poison Center in Denver, and there is no statistical curve showing what disorders occur at what level of contamination.

Nor is there consensus on how long one must be exposed to the dioxin to be considered in danger. The level of 1 part per billion described by the federal Centers for Disease Control (CDC) in Atlanta is the smallest measurable and is expected to result in one extra case of cancer per 1 million persons, but it assumes a lifetime, or 70-year exposure, to the chemical.

Doctors at the Rocky Mountain Poison Center said there is no way of knowing how often those cases increase when the parts per billion are 10, or hundreds of times greater.

At the CDC, a spokesman described the chances for contamination as "exceedingly remote" based on information from the U.S. Army and the Boy Scouts of America. "Our estimate is that no harm was done," said spokesman Robert Alden. "We feel that any medical testing of boys at this time is unnecessary."

At the Rocky Mountain Center, however, doctors said they have told several hundred concerned callers that in their opinion the Army's on-site soil test won't do the job.

"The sign on our board today says, 'Test the boys, not the soil,' " said poison center Director Dr. Barry Rumack. "I proposed to the CDC and the Department of Defense last Friday that the only way to really handle this is to get a statistical sample of the people who were there at the time and compare a control group. If we see more symptoms than we figured, then we know we have a problem. If we don't, fine."