Help with ? about poor air quality in pool - coughing swimmers

I work out at a small YMCA pool. We have had increasing problems with our swim team kids and some of the masters swimmers struggling to breathe in the pool area during workouts (more than normal!). We get an asthma-like coughing response when working hard, and some kids now get it as soon as they walk in the pool room. My observation is that the problem has worsened recently. When asking the obvious questions of the staff, there has been no known change in the chemicals, etc. We get mostly shrugs of denial from the YMCA. This really concerns us as parents and swimmers about what we are doing to our athletes' respiratory systems. How can I get this problem diagnosed? What sort of professional could evaluate the problem? It could be an air quality issue caused by a chemical treatment problem, or an HVAC air handling problem, or both. Poor ventilation has been one theory. Any suggestions?