Air Force personnel who served in the gulf war are far more likely than those who didn't to suffer chronic, unexplained symptoms such as fatigue, memory loss and joint pain, a government study concluded.

The findings from the Centers for Disease Control and Prevention support numerous previous studies showing evidence that thousands of the 700,000 personnel sent to the 1991 war suffer from a variety of unexplained symptoms, which some call "gulf war syndrome."The CDC researchers were unable to link the symptoms to any biological agent or particular disease.

The study, published in Wednesday's Journal of the American Medical Association, arose from a 1994 Pentagon request that the CDC investigate a "mystery illness" among gulf war vets from an Air National Guard unit in Lebanon, Pa.

Led by Dr. Keiji Fukuda, a CDC epidemiologist, the researchers in 1995 compared the health of members of the Pennsylvania unit and others who served in the Persian Gulf with those in three other Air Force units.

The researchers asked subjects whether they suffered from one of 35 symptoms and then categorized cases as either severe or mild-to-moderate.

Mild-to-moderate illness was found in 39 percent of the gulf war veterans, compared with 14 percent of the non-vets. Severe cases were found in 6 percent of the vets but in just 0.7 percent of non-vets.

Lab tests for various illnesses and biological agents, such as anthrax, showed no link between symptoms and gulf war status. Tests for chemical agents were not done.