Temporal and spatial variations in organic and elemental carbon concentrations in PM10/PM2.5 in the metropolitan area of Costa Rica, Central America

Comparison of Measurement-Based Methodologies to Apportion Secondary Organic Carbon (SOC) in PM2.5: A Review of Recent Studies

“…Seasonal and regional variations of SOA have been examined thoroughly over the North American continent using the EC-tracer method [1,38,89,92,93,109,[113][114][115][116][117][118][119][120][121]. Overall, annual SOC levels ranged from 1.1 to 2.7 µgC m −3 , contributing to 27-70% of PM 2.5 OC ( Figure 2; Table SA2 (SM)).…”

“…SOC estimates in warm periods in the US obtained from the literature showed that 29-43% (1.0-1.8 µgC m −3 ) of PM 2.5 OC was secondary, with the highest contribution (43%, 1.2 µgC m −3 ) at a rural location (Centreville) ( Figure 3, Table SA3 (SM)). Few examples of SOC estimations are also available in Central and South America [109,[118][119][120][121] ( Figure 2). The annual average SOC contribution was approximately 57% and reached up to 87% of PM 2.5 OC in Mexico [109] (Figure 2, Table SA2 (SM)).…”

Concentrations of aliphatic and polycyclic aromatic hydrocarbons in ambient PM2.5 and PM10 particulates in Doha, Qatar

“…Furthermore, the average PM 2.5 /PM 10 ratio was about 0.30, a typical value for sampling sites affected by the desert environment as reported in the Eastern Mediterranean (0.26) (Kocak, Mihalopoulos, and Kubilay 2007), Arizona, USA (0.28) (Mar et al 2000), Jeddah, Saudi Arabia (0.33) (Khodeir et al 2012) California, USA, (0.35) (Ostro, Broadwin, and Lipsett 2000), Negev Desert, Israel (0.35) (Andreae et al 2002), and Kuwait (0.40) (Brown et al 2008). However, higher PM 2.5 /PM 10 ratio values were reported in typical urban sites like in Zhengzhou, China (0.66) (Wang et al 2017), urban areas of Costa Rica (0.55-0.77) (Murillo et al 2013), multiple urban sites of France (0.63), Italy (0.65), and the northeastern United States (0.54) (Sorek-Hamer et al 2017), and across 20 European study areas (0.49-0.74) (Eeftens et al 2012). The low value of this ratio indicates the dominance of coarser particles that are primarily associated with mineral/fugitive dust and marine aerosols (Kocak, Mihalopoulos, and Kubilay 2007;Murillo et al 2013;Pipal and Satsangi 2015) in the arid Qatar Peninsula.…”

“…However, higher PM 2.5 /PM 10 ratio values were reported in typical urban sites like in Zhengzhou, China (0.66) (Wang et al 2017), urban areas of Costa Rica (0.55-0.77) (Murillo et al 2013), multiple urban sites of France (0.63), Italy (0.65), and the northeastern United States (0.54) (Sorek-Hamer et al 2017), and across 20 European study areas (0.49-0.74) (Eeftens et al 2012). The low value of this ratio indicates the dominance of coarser particles that are primarily associated with mineral/fugitive dust and marine aerosols (Kocak, Mihalopoulos, and Kubilay 2007;Murillo et al 2013;Pipal and Satsangi 2015) in the arid Qatar Peninsula.…”

“…It was also observed ( Figure S3) that PM 2.5 and PM 10 have a weak correlation (R 2 = 0.49), suggesting primary sources of PM 2.5 and PM 10 might be different. Fine particles could originate from local industrial and vehicular activities, while coarse particles could be marine aerosols, soil dust, and fugitive dust (Murillo et al 2013;Pipal and Satsangi 2015). Furthermore, the average PM 2.5 /PM 10 ratio was about 0.30, a typical value for sampling sites affected by the desert environment as reported in the Eastern Mediterranean (0.26) (Kocak, Mihalopoulos, and Kubilay 2007), Arizona, USA (0.28) (Mar et al 2000), Jeddah, Saudi Arabia (0.33) (Khodeir et al 2012) California, USA, (0.35) (Ostro, Broadwin, and Lipsett 2000), Negev Desert, Israel (0.35) (Andreae et al 2002), and Kuwait (0.40) (Brown et al 2008).…”