The World Trade Center disaster and its recovery work involved a range of hazardous occupational exposures that have not been fully characterized but that can be reasonably assumed to have the potential to cause mucosal inflammation, preferentially (but not exclusively) in the upper airway. A high prevalence of rhinosinusitis and upper airway disease (UAD) symptoms was reported by several early surveys. Clinical studies demonstrated objective, clinically significant, and persistent chronic perennial rhinosinusitis and UAD—with or without seasonal exacerbation—in a large proportion of patients. Demonstration of an association between UAD and available exposure indicators has been limited. Atopy seemed to be associated with increased UAD symptom severity and to be a risk factor for upper, but not lower, airway disease. World Trade Center-related UAD is considered an irritant-induced disease but not, in many cases, of acute onset. No data thus far suggest an increased upper airway cancer incidence.