SOURCE APPORTIONMENT OF WINTERTIME PM(10) AT SAN-JOSE, CALIF

A Pilot air-quality monitoring study was conducted at two locations in San Jose, Calif., between 12/16/91 and 2/24/92, with daytime (0600 to 1800 PST) and nighttime (1800 to next day 0600 PST) PM(10) (particulate matter with an aerodynamic diameter less than or equal to 10 mu m) samples. Source profiles (the fractional chemical composition of emissions) from local paved road dust were combined with source profiles from other studies for input to the Chemical Mass Balance (CMB) receptor model to apportion the measured PM(10) to sources and to determine the additional information needed to develop emission-reduction strategies. Residential wood combustion was the largest contributor during this period, especially to nighttime samples, and averaged approximately 45% of the PM(10) mass. Other significant sources included primary motor vehicle exhaust, resuspended road dust, and secondary ammonium nitrate, each contributing between 15% and 20% of the average wintertime PM(10). Secondary ammonium sulfate and primary marine aerosol contributions were detectable, but these contributed less than 5% to the average PM(10).