Paterson City, NJ, was selected for the Urban Community Air Toxics Monitoring Project (UCAMPP) because it has mixed land-use with a high population density and multiple air toxic sources, e.g., stationary emissions from metal plating and recovery plants, area emissions from commercial boilers, and mobile emissions from US interstate highway Route 80 and a major NJ Transit Bus Depot. To examine the potential impact from local industrial, commercial, and mobile sources in Paterson, a background site in Chester was monitored concurrently for comparison. A suite of air toxics, e.g., aldehydes, PAH, VOC, elemental carbon, organic carbon, hexavalent chromium (Cr-VT), and trace elements in PM10 were measured during UCAMPP. Significant seasonal variations in ambient Cr-VT concentrations were observed in both Paterson and Chester. Ambient Cr-VT concentrations were not associated with total Cr. The regression analyses were consistent with the spatial and temporal variability results that showed significant differences in season but not in sampling site or a day of the week. This is an abstract of a paper presented at the 101st AWMA Annual Conference and Exhibition (Portland, OR 6/24-27/2008).