Concentrations of alkanes (C20–C35), 14 polycyclic aromatic hydrocarbons (PAHs) and PAH ketones, and three hopanes are reported from four locations near the World Trade Center (WTC) (three of the locations within 300m of the debris pile). The highest concentrations of individual PAHs across the four locations were for fluoranthene (10.3ng/m3 at site W), pyrene (8.7ng/m3 at site W), and chrysene (6.2ng/m3 at site W). The EPA Unmix Version 6.0 receptor model was used to estimate the impact of WTC fires and recovery efforts on ambient PM2.5 concentrations. Five factors were identified: open burning of building debris, smoldering fires from building debris, a mixed recovery source, a sulfate/debris removal source, and motor vehicle exhaust.