The major PM2.5 constituents across all sites (relative contribution ± SD) are ammoniated sulfate (20 % ± 11 %), crustal material (13.4 % ± 9.9 %), equivalent black carbon (11.9 % ± 8.4 % 2.5. PM2.5 COMPOSITION, SOURCES, AND AIR Figure 2.5.1. Chemical composition of the fine aerosol compared with the total PM2.5 mass for the second half of the Atlanta Supersite Study. Plot (a) shows results from a 24-hr average and (b) 1-hr average. Events dominated by SO42-are indicated by 2s-4s and events dominated by organic
The mass scattering efficiency (MSE) of PM 2. 5 ranged from 3.0 to 5.0 m 2 g 1 for aerosols produced from anthropogenic emissions and from 0.7 to 1.0 m 2 g 1 for natural dust aerosols. The mass absorption efficiency (MAE) of EC ranged from 6.5 to 12.4 m 2 g 1 in urban environments, but the MAE of water-soluble organic carbon was only 0.05 to 0.11 m 2 g 1 . Characterization of PM2.5 chemical composition at the 1. Environ Sci Pollut Res Int. 2017 Apr;24(12):11836-11846. doi:10.1007/s11356-017-8684-3. Epub 2017 Mar 25. Characterization of PM2.5 chemical composition at the Demokritos suburban station, in Chemical Composition of PM2.5 Based on Two-Year While sulfate and nitrate contributed 32% and 21% to PM2.5 for acidic aerosols, and 22%, 17% of PM2.5 from sulfate and nitrate for neutral aerosols. Chemical Composition of PM2.5 Based on Two-Year Measurements at an Urban Site in Beijing - Aerosol and Air Quality Research
Exposure to ambient fine particulate matter (PM2.5) is a leading risk factor for the global burden of disease. However, uncertainty remains about PM2.5 sources. We use a global chemical transport model (GEOS-Chem) simulation for 2014, constrained by satellite-based estimates of PM2.5 to interpret globally dispersed PM2.5 mass and composition measurements from the ground-based surface PM2.5 chemical composition and spatiotemporal PM 2.5 chemical composition and spatiotemporal variability during the California Regional PM 10/PM 2.5 Air Quality Study (CRPAQS) Judith C. Chow,1 L.-W. Antony Chen,1 John G. Watson,1 Douglas H. Lowenthal,1 Karen A. Magliano,2 Kasia Turkiewicz,2 and Donald E. Lehrman3 Received 1 July 2005; revised 7 December 2005; accepted 4 January 2006; published 25 May 2006. PM2.5 chemical composition at a rural background site PM2.5 Chemical composition Correlation analysis Air mass back trajectory 1. Introduction Atmospheric aerosols have been of environmental concern since the Industrial Revolution. The discovery and increased understanding of their detrimental health and environmental effects gave rise to policies
Daily PM2.5concentrations ranged from 15.9 to 156.7 µg m3with an average of 66.0 ± 35.1 µg m3. The average PM2.5mass during the Olympics decreased by 49% from the second stage (20 July to 7 August), mainly due to the reduction of secondary inorganic aerosols (i.e., sulfate, nitrate, and ammonium (SNA)). Spatial and Temporal Variation in PM2.5 Chemical Strong seasonal and geographic variations in PM 2.5 chemical composition are identified. Only seven of the 52 components contributed 1% to total mass for yearly or seasonal averages [ammonium (NH 4 + ), elemental carbon (EC), organic carbon matter (OCM), nitrate (NO 3 ), silicon, sodium (Na + ), and sulfate (SO 4 2 )]. Surface PM2.5 Atmospheric Composition Analysis Group Aerosol optical depth (AOD) from the NASA MODIS C6.1, MISR v23, MAIAC C6, and SeaWiFS satellite products are combined and related to surface PM2.5 concentrations using geophysical relationships between surface (PM 2.5) and AOD simulated by the GEOS-Chem chemical transport model.
We estimate ground-level fine particulate matter (PM 2.5) total and compositional mass concentrations over North America by combining Aerosol Optical Depth (AOD) retrievals from the NASA MODIS, MISR, and SeaWIFS instruments with the GEOS-Chem chemical transport model, and subsequently calibrated to regional ground-based observations of both total and compositional mass using Geographically Trends in ambient air pollution levels and PM 2.5 chemical Wang X, Bi X, Sheng G, et al. Chemical composition and sources of PM10 and PM2.5 aerosols in Guangzhou, China. Environ Monit Assess 2006;119:425-39. Feng QD, Dang Z, Lv XW, et al. Chemical speciation distribution of PM2.5 - bound heavy metals in the air. Ecol Environ Sci 2011;20:1048-52. Trends in ambient air pollution levels and PM 2.5 chemical Wang X, Bi X, Sheng G, et al. Chemical composition and sources of PM10 and PM2.5 aerosols in Guangzhou, China. Environ Monit Assess 2006;119:425-39. Feng QD, Dang Z, Lv XW, et al. Chemical speciation distribution of PM2.5 - bound heavy metals in the air. Ecol Environ Sci 2011;20:1048-52.
Implications:PM 2.5 mass and chemical composition show large contributions from carbon, sulfate, nitrate, ammonium, and fugitive dust during winter and summer and across fourteen large cities. Multipollutant control strategies will be needed that address both primary PM 2.5 emissions and gaseous precursors to attain China's recently adopted PM 2.5 national air quality standards. Chemical Composition of PM2.5 and Its Impact on Inhalation The results showed that the daily average PM2.5 concentration ranged from 21 to 255 µg/m3, with an annual average of 73 ± 49 µg/m3. SO42, NO3, NH4+, and organic matter (OM) were the dominant components, accounting for 13%, 20%, 11%, and 20% of annual PM2.5 mass loading, respectively.