Intra-community spatial variation of size-fractionated PM mass, OC, EC, and trace elements in the Long Beach, CA area
Department of Civil and Environmental Engineering, University of Southern California, 3620 South Vermont Avenue, Los Angeles, CA 90089, USA Atmospheric Environment
(Impact Factor: 3.28).
07/2008; 42(21):5374-5389. DOI: 10.1016/j.atmosenv.2008.02.060
Local traffic patterns and proximity to pollution sources are important in assessing particulate matter (PM) exposure in urban communities. This study investigated the intra-community spatial variation of PM in an urban area impacted by numerous local and regional sources. Weekly size-segregated (<0.25, 0.25–2.5, and >2.5 μm) PM samples were collected in the winter of 2005. During each 1-week sampling cycle, data were collected concurrently at four sites within four miles of one another in the Long Beach, CA area. Coefficients of divergence analyses for size-fractionated PM mass, organic and elemental carbon, sulfur, and 18 other metals and trace elements suggest a wide range of spatial divergence. High spatial variability was observed in the <0.25 μm and 0.25–2.5 μm PM fractions for many elements associated with motor vehicle emissions. Relatively lower spatial divergence was observed in the coarse fraction, although road dust components were spatially diverse but highly correlated with each other. Mass and OC concentrations were homogeneously distributed over the sampling sites. Possible oil combustion sources were identified using previously documented markers such as vanadium and nickel and by distinguishing between primary sulfur and secondary sulfate contributions. This study shows that, although PM mass in different size fractions is spatially homogeneous within a community, the spatial distribution of some elemental components can be heterogeneous. This is evidence for the argument that epidemiological studies using only PM mass concentrations from central sites may not accurately assess exposure to toxicologically relevant PM components.
Available from: Caiqing Yan
- "Atmospheric scales of air pollutant transport can be roughly categorized into microscale (0–100 meters), mesoscale (tens to hundreds of kilometers), synoptic scale (hundreds to thousands of kilometers) and global scale (> 10 3 kilometers). Both PM 2.5 and BC have been classified as mesoscale air pollutants that can travel tens to hundreds of kilometers (Krudysz et al., 2008; Wang et al., 2011). This is because their atmospheric lifetime is fairly long so that they can be transported and dispersed within a large region (Cape et al., 2012; Chen et al., 2013 "
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ABSTRACT: Developing countries, such as China, are facing serious air pollution issues due to fast economic development. In this study, traffic related air pollutants, including number concentration of ultrafine particles (UFPs, diameter < 100 nm), mass concentrations of PM2.5and black carbon (BC) were measured near the Peking University (PKU) campus in Beijing in December 2011. Data were collected concurrently at a roadway site and on PKU campus. Meteorological data were collected at approximately 40 meters northeast from the roadway sampling site. The traffic density was determined from recorded video footage. Roadside UFP and PM2.5concentrations were not significantly higher than on campus. A statistically significant Pearson’s correlation of 0.75 was found between BC and PM2.5mass concentrations. No apparent correlation was found between wind speed and UFP number concentrations, but strong log-decay correlations were found between wind speed and PM2.5(R2= 0.80). There were three days during the measurements when both PM2.5mass concentrations and UFP number concentrations were higher at the campus site than at the roadway site. This suggests there were potential local emission sources on campus. Temporal profile of UFPs at the campus site peaked around lunch and dinner time, suggesting emissions from the surrounding restaurants and cafeteria that used Chinese-style cooking might have contributed to the observed PM2.5and UFP levels on campus.
Aerosol and Air Quality Research 08/2015; 15(4). DOI:10.4209/aaqr.2014.11.0295 · 2.09 Impact Factor
Available from: Jyoti Prakash Maity
- "While particulate mass concentrations can be spatially homogeneous, certain toxic particulate components may be unevenly distributed originating from specific sources, creating a potential for exposure of large populations to healthrelevant particulate components (Krudysz et al. 2008). Assessing population exposure to particulates thus requires evaluation of the communityscale spatial variability representing different elemental particulates as well as toxicologically relevant components. "
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ABSTRACT: This study proposes a practical method to estimate elemental composition and distribution in order to attribute source and quantify impacts of aerosol particles at an urban region in Kolkata, India. Twelve-hour total particulates were collected in winter (2005-2006) and analyzed by energy-dispersive X-ray fluorescence technique to determine multi-elemental composition, especially trace metals. The aerosols consist of various elements including K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, and Pb which exhibit significant concentration at various sites (p < 0.05). The concentration of different metallic elements were found in the order of Zn > Pb > Ni > Cu > Cr > Co. Statistical multivariate analysis and correlation matrix analyses were performed for factor identification and consequent source apportionment. Contour profiles demonstrate spatial variation of elemental compositions indicating possible source contribution along with meteorological influences. Spatial differences were clearly most significant for Zn, Ni, Pb, and Cu reflecting the importance of anthropogenic inputs, primarily from automobile sources.
Environmental Monitoring and Assessment 09/2010; 168(1-4):561-574. DOI:10.1007/s10661-009-1134-z · 1.68 Impact Factor
Available from: Yang Liu
- "Finally, we estimated pairwise Coefficients of Divergence (COD) to assess the degree of uniformity in the PM 2.5 concentrations as well as absolute differences in the PM 2.5 chemical compositions among the sites. COD has been used as a complementary measure to correlation analysis, to characterize spatial patterns of particulate matter in several multi-site comparative analyses (Wongphatarakul et al., 1998; Pinto et al., 2004; Kim et al., 2005; Krudysz et al., 2008). In this context, two sites may exhibit strong linear associations with each other in total PM 2.5 mass, yet have absolute levels that differ substantially; yielding both high correlations and high COD values. "
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ABSTRACT: This manuscript presents results from an extensive, multi-country comparative monitoring study of fine particulate matter (PM2.5) and its primary chemical components in Israeli, Jordanian and Palestinian cities. This study represented the first time that researchers from these countries have worked together to examine spatial and temporal relationships for PM2.5 and its major components among the study sites. The findings indicated that total PM2.5 mass was relatively homogenous among many of the 11 sites as shown from strong between-site correlations. Mean annual concentrations ranged from 19.9 to 34.9 μg m−3 in Haifa and Amman, respectively, and exceeded accepted international air quality standards for annual PM2.5 mass. Similarity of total mass was largely driven by SO42− and crustal PM2.5 components. Despite the close proximity of the seven, well correlated sites with respect to PM2.5, there were pronounced differences among the cities for EC and, to a lesser degree, OC. EC, in particular, exhibited spatiotemporal trends that were indicative of strong local source contributions. Interestingly, there were moderate to strong EC correlations (r > 0.65) among the large metropolitan cities, West Jerusalem, Tel Aviv and Amman. For these relatively large cities, (i.e., West Jerusalem, Tel Aviv and Amman), EC sources from the fleet of buses and cars typical for many urban areas predominate and likely drive spatiotemporal EC distributions. As new airshed management strategies and public health interventions are implemented throughout the Middle East, our findings support regulatory strategies that target integrated regional and local control strategies to reduce PM2.5 mass and specific components suspected to drive adverse health effects of particulate matter exposure.
Atmospheric Environment 06/2010; 44(20-44):2383-2392. DOI:10.1016/j.atmosenv.2010.04.007 · 3.28 Impact Factor
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