Offices in a high-rise office building in Pittsburgh, PA were experiencing indoor air quality issues following restoration work to repair flood damage caused by a cooling tower malfunction. Occupants continued to complain of eye and skin irritation, and hay fever-like symptoms. Consultants involved in the restoration work were unable to determine the cause of the continuing issues. We were commissioned to investigate the situation and find a solution.
Interviews of those involved in the restoration work determined that damage included collapse of suspended ceiling tiles, and flooding of the space. Water had saturated duct insulation above ceilings, ceiling tiles, drywall, carpeting and all contents. Drying had been promptly performed, and water damaged ceiling tiles and contents removed. Drywall was repaired, carpeting was cleaned and retained, and duct insulation was dried and retained. We performed a detailed inspection of the impacted area and collected samples of dust and air for analysis by scanning electron microscopy (SEM). Analysis of the samples found that, while the space had been dried quickly enough to prevent mold growth, irritant particulate matter, including mineral wool from damaged ceiling tiles, drywall dust, and fiberglass remained in the carpeting and interstitial spaces. Air sampling demonstrated that this particulate became airborne during normal occupation of the space. Normal cleaning procedures, such as had occurred after restoration of the space, are inadequate to remove such particulate.
We designed a cleaning procedure targeting the offending particulate, and monitored the cleaning work. Following this work, clearance dust and air sampling were performed to verify that the cleaning had removed the offending particulate. Following this work, there were no more indoor air quality complaints related to the flood event.