Air Force Reserve members who flew C-123 aircraft after they were used for spraying Agent Orange in Vietnam were exposed to the toxic herbicide and may be at risk for developing related diseases, according to a federal study released Friday.

An Institute of Medicine scientific panel comprised of public health experts stated "with confidence" that some of the 1,500 to 2,100 Air Force Reserve personnel who flew on C-123s after the war were exposed to chemical levels that exceed health guidelines for workers.

Subsequently, they may face increased risk for developing illnesses associated with exposure to the components of Agent Orange, according to the study.

The findings — from aan educated group led by Harvard Public Health expert Robert Herrick — are a hard-fought victory for a small group of former service members who have lobbied for years to be included among those presumed to be exposed to Agent Orange as a result of their military service.

Led by retired Air Force Maj. Wes Carter, the members of the C-123 Veterans Association have pushed the Veterans Affairs Department to recognize illnesses they've developed and say are related to exposure.

But VA consistently has maintained that trace amounts of dioxin on the metal surfaces in the aircraft, which were stripped of their spraying apparatus after the war, would not pose a threat to troops because it is not "biologically available for skin absorption or inhalation."

The VA's stand, according to the department's C-123 exposure website is that "although residual TCDD — the toxic substance in Agent Orange — may be detected in C-123 aircraft by sophisticated laboratory techniques many years after its use, the [VA] concluded that the existing scientific studies and reports support a low probability that TCDD was biologically available in these aircraft. Therefore, the potential for exposure to TCDD from flying or working in contaminated C-123 aircraft years after the Vietnam War is unlikely to have occurred at levels that could affect health."

But according to Carter and the Vietnam Veterans of America, at least 10 C-123 crewmen who flew in the aircraft after the war have died of cancers commonly linked to Agent Orange.

And with many of his former colleagues ill or dying, Carter expanded his lobbying efforts to veterans service organizations, Congress and academia to help obtain health care and, if those sickened rate it, compensation.

In early 2014, VA paid the IOM $500,000 to study the issue and put the controversy to rest.

But the report's conclusions do not support VA's long-maintained position.

In developing the report, panel members reviewed existing evidence, public input, interviews with experts and existing tests performed on the aircraft.

The group found that while the evidence is limited, the data indicate that the Reserve members could have been exposed through multiple routes and "some reservists quite likely experienced non-trivial increases in their risks of adverse health outcomes."

The findings, which the VA received Thursday, have stirred action within the Veterans Affairs Department. The VA has 60 days to respond to the report, but on receipt of it Thursday, officials held the first meeting of a working group to address related issues and is planning follow-up action.

Deputy Secretary Sloan Gibson attended the working group meeting, and VA Undersecretary for Benefits Allison Hickey was to be briefed Friday on the findings as well, according to VA officials.

"I can't speak for [Hickey] but I know it is an important issue for her," said

VA Assistant Secretary for Policy and Planning Dr. Linda Schwartz during a public briefing on the report at the National Academy of Sciences in Washington, D.C.

Schwartz said in addition to determining who has been affected, VA must also assess whether legislative action is needed to offer them health care and benefits.

From 1962 to 1971, C-123s sprayed more than 10 million gallons of Agent Orange on enemy encampments and the dense jungles of Southeast Asia.

Following the war, they were assigned to squadrons at Westover Air Reserve Base, Massachusetts; Pittsburgh Air Reserve Base; and Rickenbacker Air National Guard Base, Ohio.

One C-123 nicknamed "Patches" is on display at the National Museum of the U.S. Air Force at Wright-Patterson Air Force Base, Ohio.

But before Patches could be moved into the museum in 1994, it was deemed too contaminated to go on display and scrubbed down by a hazardous materials crew.

The Air Force also destroyed 18 C-123s in 2010, cutting them down and smelting them out of concerns about potential liability for Agent Orange, according to Air Force documents.

In its report, the panel did not weigh in on whether the VA should approve compensation claims filed by C-123 veterans but noted in strong, unequivocal language that the veterans were exposed.

"The committee is firm in its conviction that Air Force reservists working in C-123s were exposed (in the technical sense of the word of having bodily contact with the chemicals) to the components of Agent Orange to some extent. The committee members could not stand behind any particular exposure estimates produced by manipulating the existing data, but they are clear in their finding that the [evidence is] fully consistent with exposures that exceeded international guidelines."

Following the briefing, Carter, who has cancer and heart disease he believes is linked to Agent Orange exposure, said he was relieved by the findings and hopes for swift action from VA.

"[Retired Air Force Brig.] General Hickey said she'd go by the decision of the IOM ... [VA] needs to act quickly, because this is not solely about compensation. These are veterans who should have been entitled to medical care at the VA and those doors were shut," Carter said.

He noted that as a military retiree who was injured during the Persian Gulf War, he already is eligible for VA care. The fight, he said, was for those who are gravely ill and have no health benefits or can't work because of their illnesses.

With the new decision by the IOM panel, he hopes they'll get help, he said.

"This was my last trip to D.C.," he said. "And it was worth it."