The Veterans Affairs Department is weighing whether to add several diseases to the list of health conditions presumed in Vietnam veterans to be caused by exposure to Agent Orange.

A VA working group is studying a report issued in March by the Institute of Medicine to determine whether bladder cancer, hypothyroidism and Parkinson's-like symptoms — illnesses the IOM said may be more strongly linked to exposure than previously thought — should automatically make a Vietnam veteran eligible for VA disability benefits and health care.

According to Dr. Ralph Erickson, VA's chief consultant for post-deployment health services, the group will make a recommendations to VA Secretary Robert McDonald on whether the diseases should be added to a list of 15 already in place.

"We are in the midst of a deliberative process, carefully looking at all the IOM committee put in the report and additional information that has come out since," Erickson said. "We will be putting together a VA response that will be brought before senior leaders and ultimately brought before the secretary."

The process could take up to two years, a VA spokeswoman added.

Roughly 1 million Vietnam veterans are enrolled in the VA health system, according to the department. Based on a review of data for one year, 5,484 of these veterans have been diagnosed with bladder cancer, 15,983 suffer from hypothyroidism and an estimated 1,833 have Parkinson's-like symptoms.

The working group also is looking into the role, if any, Agent Orange exposure has played in the development of hypertension in Vietnam veterans. According to VA, 307,324 Vietnam veterans in the Veterans Health Administration have high blood pressure.

"Hypertension has been a question that has been asked," Erickson said. "The cohort of men and women who heroically served their country in uniform and went to Vietnam are in their 60s, 70s and 80s, and these individuals, merely because of their age, are starting to accrue chronic diseases that come with aging. It's a delicate matter to tease out whether someone has hypertension because of their age or whether it would be related to an exposure to Agent Orange."

VA began recognizing diseases associated with herbicide exposure in Vietnam beginning in 1991, naming 15 diseases as presumed to be related, including Hodgkin's disease, multiple myeloma, non-Hodgkin's lymphoma, early-onset peripheral neuropathy, porphyria cutanea tarda, prostate cancer, respiratory cancers, soft-tissue sarcoma, chloracne, type-2 diabetes mellitus, light chain amyloidosis, ischemic heart disease, chronic B-cell leukemias, Parkinson's disease, and spina bifida in offspring of veterans.

The most recent IOM report actually downgraded spina bifida in the children of Vietnam veterans, saying research does not support a previously held belief that the disease occurred in offspring of exposed veterans at higher rates.

But the change of spina bifida from "limited or suggestive evidence" it is related to exposure to "inadequate or insufficient" evidence should not affect disability payments to the 1,153 descendants of Vietnam veterans who receive them, Veterans Benefits Administration senior adviser for compensation services Brad Flohr said.

VA recommends that veterans who have an illness they believe is related to Agent Orange exposure file a claim; they are considered on a case-by-case basis if the illness is not on the presumptive condition list.

Should new diseases be added to the list, the regulation would go into effect 30 days after it is published in the Federal Register.

If a veteran dies of a condition determined to be a presumptive condition after the veteran's death, VA will provide dependency and indemnity compensation benefits to eligible spouses, children and parents of that veteran.

Patricia Kime covers military and veterans health care and medicine for Military Times. She can be reached at pkime@militarytimes.com.