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) (particula te matter with an aerodynamic diameter less than or equal to 10 mu m) samples. Source profiles (the fractional chemical composition of emiss ions) from local paved road dust were combined with source profiles fr om other studies for input to the Chemical Mass Balance (CMB) receptor model to apportion the measured PM(10) to sources and to determine th e additional information needed to develop emission-reduction strategi es. Residential wood combustion was the largest contributor during thi s period, especially to nighttime samples, and averaged approximately 45% of the PM(10) mass. Other significant sources included primary mot or vehicle exhaust, resuspended road dust, and secondary ammonium nitr ate, each contributing between 15% and 20% of the average wintertime P M(10). Secondary ammonium sulfate and primary marine aerosol contribut ions were detectable, but these contributed less than 5% to the averag e PM(10).