- 1University of Silesia in Katowice, Institute of Chemistry , Katowice, Poland (istanimi@us.edu.pl)
- 2Department of Public Health Sciences, University of Rochester Medical Center, Rochester, NY, USA
- 3Institute for Sustainable Environment, Clarkson University, Potsdam, NY, 13699 USA
Assessing the site-to-site variability of source contributions to the ambient PM2.5 concentrations plays an important role in estimation of exposure misclassification in epidemiological studies. Exposure misclassification error may be substantially lowered when accounting for the heterogeneity of source contributions resulting in a lower relative risk evaluation.
The aims of this study were to identify the common pollution sources and their contributions from the PM2.5 compositional data collected during the two sampling campaigns (2012/13 and 2018/19) of the Multiple Air Toxics Study (MATES) at ten sites across the South Coast Air Basin using positive matrix factorization and to characterize the spatial variations among the source contributions by coefficients of determination and divergence.
The results of the study showed that the major common contributor to the PM2.5 mass at all sampling sites was the “gasoline vehicle” source followed by “aged sea salt”, “biomass burning”, “secondary nitrate”, “secondary sulfate”, “diesel vehicles”, “soil/road dust” and “OP-rich”. The contribution patterns of all eight sources were highly heterogeneous over time. Among them, the highest spatial variability was found for the contributions from “OP-rich” source in both MATES campaigns suggesting the different wildfire contributions that occurred in the region. Alternatively, the smallest spatial site diversities were observed for the highly correlated contributions of the “secondary sulfate” and “aged sea salt” sources obtained from the MATES data collected in 2012/13 and for the “soil/road dust” sources from 2018/19 campaign. Overall, the source contributions obtained for Inland Valley and Rubidoux were the most different in comparison to the other sites likely due to their distant location from the Pacific Ocean and the major industrial region in Los Angeles.
How to cite: Stanimirova, I. and Hopke, P. K.: Assessment of spatial variability in PM2.5 source contributions during two sampling campaigns (2012/13 and 2018/19) across ten sites in the South Coast Air Basin, California, the USA., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14163, https://doi.org/10.5194/egusphere-egu25-14163, 2025.
