Primary and secondary carbonaceous species in the atmosphere of Western Riverside County, California

摘要: Elemental carbon (EC), organic (OC) and PM2.5 mass concentrations were measured from September 2001 through January 2002 in Mira Loma, CA. EC OC analyzed using the NIOSH (National Institute of Occupational Safety Health) 5040 thermal/optical transmittance method. Loma found to be higher than those other urban sites South Coast Air Basin (SoCAB), while comparable or lower SoCAB sites. Overall, accounted for 26% 5% total PM2.5, respectively. OC/EC ratios ranged 1.6 12.8 with an average 5.2. These values observed at United States by a factor 2. A stronger correlation between suspended was noted months photochemical activity (December January, r=0.82) greater (September October, r=0.64). The elevated levels OC, ratios, seasonal difference attributed part significant secondary aerosol formation. fraction that (SOC) estimated minimum ratio method Chemical Mass Balance (CMB) modeling. Based on method, contribution SOC tended during (63%) (44%). CMB modeling, contributed 14% 57% study period. these findings suggest can appreciably affect measures control emissions precursors incorporated as region-wide air quality management plan could lead perceptible drop this area.