A new Air Force report says an often-cited 1984 government study that was supposed to be "reassuring" for Vietnam veterans exposed to Agent Orange was flawed.

The revised study said while the chemical defoliant could not be "confidently identified" as the reason for a series of health problems among veterans who handled the chemical, it could not be "exonerated" either.The report, released Monday by Sens. John F. Kerry, D-Mass., and Tom Daschle, D-S.D., was hailed by veteran activists as a major breakthrough.

"For the first time the Air Force is saying in a major way that they cannot rule out dioxin as the cause of ill-health effects," said Barry Kasinitz, spokesman for Vietnam Veterans of America.