LORDS VALLEY, Pa. — Daniel Mould’s sense of abandonment was profound.

An Air Force staff sergeant wounded in a chemical weapon accident in 2004, he willingly helped the military study his wounds. From his bed in a Philadelphia burn ward, as blisters from sulfur-mustard agent erupted on his skin, he signed a waiver allowing doctors to gather his body fluids to experiment with new laboratory methods for confirming chemical exposure.

Over the next 18 months, as the military gave him attentive care and doctors prepared peer-reviewed journal articles about his case, another branch of the service, the Army, concluded that it needed to be exhaustive in tracking troops exposed to chemical warfare agents: Citing Sergeant Mould’s burns, it called for monitoring victims for life.

The case seemed a welcome example of the military’s working closely with a patient to improve understanding of a rare battlefield risk and to develop practices to learn from patients’ medical experiences. Then came the shift.

When Sergeant Mould accepted medical retirement in 2006, he was suffering a cascade of health problems, but he said he had been assured of long-term monitoring. Instead, he said, “the Air Force never contacted me again. I’ve never been tracked.”