Karaj, Iran ? His frail body perched on a pillow, Ali Shakiebeinejad whispered a few words at a time through a green plastic mask connected to an oxygen canister.

“I first noticed the beautiful smell. It was sweet, like garlic or roses,” the former shoe repairman recalled. A deep racking cough interrupted him. “But I didn’t know what it was.”

Then only 19, the Iranian was too preoccupied with the rout of his military unit and his impending capture by the Iraqis. And for the next 27 months he was a prisoner of war.

Five years ago, the growing number of unusual symptoms – a worsening cough, constant respiratory infections, gum disease that caused his teeth to fall out, pounding headaches and excessive weight loss – were finally diagnosed. Doctors told Shakiebeinejad that he was a victim of mustard gas, the chemical weapon most used by Iraq during its eight-year war with Iran.

In a declassified report, the CIA estimated in 1991 that Iran suffered more than 50,000 casualties, including untold thousands of deaths, from Iraq’s use of several chemical weapons. But Iran claims the tally has since soared as both troops and civilians have developed the telltale symptoms up to 15 years later because low-dose exposure deferred physical deterioration or collapse.

“We are beginning to understand that we may only have seen the tip of the iceberg. We may not yet have seen the majority of victims,” said Dr. Farhad Hashemnezhad, a young pulmonary specialist who has reluctantly become an expert on chemical weapons.

“Many patients don’t know that their complaints – coughing, tightness in the chest, difficult respiration – have anything to do with chemical weapons, especially after all these years,” the doctor said. “At least 20 percent of the current patients are civilians who didn’t think they were close enough to be exposed.”

One of the common causes of civilian casualties was use of water contaminated by chemical weapons, he said.

Doctors became so concerned by the growing number of cases that the government two years ago started putting ads in Iranian papers calling on anyone who had been in specified areas during the war to report to one of the nation’s 30 centers for the disabled and get medical checkups. What the ads did not say, to avoid panic, was that the areas had been hit by Iraqi chemical weapons.