The National Institute for Occupational Safety and Health (NIOSH) received a confidential request from firefighters of Cherokee County Fire Station 21 in Ball Ground, Georgia. In the request, firefighters expressed concerns about the air quality in the building and the possibility that the indoor environment might be causing health effects experienced by some of the firefighters. Primary health concerns were: asthma, bronchitis, respiratory infections, sinusitis, growths in the sinus cavity, bloody mucous, nose bleeds, shortness of breath, coughs, fevers, eye/skin irritation, mold allergies, and diarrhea. Listed exposures included air fresheners, dirty air ducts and vents, inadequate fresh air, water leaks in restrooms, and other airborne irritants. The NIOSH response consisted of calls to requesters and county officials, reviews of Indoor Air Quality (IAQ) reports prepared by independent consultants and sent to NIOSH by the requesters, and a walkthrough of the community center that houses Fire Station 21. NIOSH also visited 4 other community centers and fire stations of the same design and built in the same time-frame by county contractors. During the walkthrough, the NIOSH industrial hygienist conducted: visual inspection of the building for indicators of mold, moisture, and dampness; real-time monitoring of temperature, relative humidity, carbon dioxide, and carbon monoxide concentration in and outside of the buildings; and use of a moisture-meter for differential determination of water content in building materials. The NIOSH medical officer conducted interviews with employees to assess what health symptoms were present and whether they may be building-related. Visual observations of conditions that were deemed to have potential for impacting IAQ were made. Visible mold, rust, and water condensation on air supply vents was found in the restrooms. Inspection of the wall cavities located between the restrooms and the kitchen area in all five of the fire stations found evidence of water damage and mold at the base of the interior wall surfaces. Visible mold was present on clothing and other items stored in the Station 21 turn-out gear room. Condensation was evident on the interior surfaces of ductwork observed through an inspection panel at the air conditioning unit. A sewer drain back-up occurred during the site visit in the Station 21 laundry room floor drain. Measured indoor relative humidity levels were above the recommended guidelines, and levels of carbon dioxide were within the recommended range. Firefighters reported various health problems including headaches, allergies/congestion, sinusitis, fatigue, and asthma. In most cases, these symptoms were perceived as temporally related to work. Firefighters who had relocated from Station 21 to other stations, reported a decrease in symptoms after leaving Station 21. Thirty-three percent of firefighters at Station 21 reported a confirmed diagnosis of asthma, a prevalence much higher than in the general population which is about 10%. Two additional firefighters were being treated with asthma medications, but had not yet been tested for asthma. If these two additional individuals are also diagnosed, this elevates the number of personnel with asthma to 44%. Of the individuals with confirmed or likely asthma, 75% never had asthma prior to working in Station 21. The other 25% reported having childhood asthma that had resolved, but recurred after working at Station 21. NIOSH conducted one walkthrough at Cherokee County Fire Station 21 in Ball Ground, GA, to address employee concerns about the indoor environment and health effects they were experiencing. We measured excessive relative humidity in the firefighter living quarters and found visible mold in plumbing chases. High rates of self-reported symptoms in Station 21 raise concern that a portion may be building-associated health effects. In particular, the prevalence of reported physician diagnosed asthma is much higher (33%) than the asthma prevalence in the general population, which is about 10%. We recommend further evaluation of the building envelope including the roof for areas of water damage or mold. Water damaged materials should be removed and replaced using appropriate precautions for protecting occupants and for persons conducting the remediation. Additionally, employees with asthma and allergic conditions should bring this report to their physicians for counsel regarding the investigation of possible work-related patterns of peak flow, airways hyper-reactivity, and/or medication use.