Is Katrina cough a legitimate new ailment or run-of-the-mill allergy?

That's the question that a five-year Tulane University study is designed to answer. Led by Henry Glindmeyer, a professor of pulmonary, critical-care and environmental medicine in Tulane's medical school, researchers are keeping tabs on the respiratory health of 1,000 local workers.

The project is underwritten by a 1.86 million dollar grant from the National Institute for Occupational Safety and Health.

Each volunteer will answer a questionnaire, undergo a noninvasive breathing test and wear a monitor for five or six hours to detect workplace exposure to dust, bacteria and mold.

This is the first long-term scrutiny of a phenomenon that people initially linked to residual damage caused by Hurricane Katrina, the ensuing floods and weeks of standing water late in the summer of 2005.

However, a state health-department study in April 2006 of more than 56,000 emergency-room visits did not find an increase in severe respiratory problems.