Spatial distribution and sources identification of elements in PM2.5 among the coastal city group in the Western Taiwan Strait region, China

The main purpose of this study was to investigate the spatial variations of 20 elements (Al, Si, Ti, Ca, Fe, Mg, Cr, Mn, Ni, P, S, K, Cu, Cl, V, Se, Br, As, Zn, and Pb) in PM2.5 (particle matters≤2.5μm in aerodynamic diameter) in the coastal city group in the Western Taiwan Strait (WTS) region, China during spring 2011. The average PM2.5 mass concentration at 13 sites was 77.0μg/m3 and the elemental fraction accounted for about 10–20%. Multivariate analyses (principal component analysis and cluster analysis) and a correlation matrix were used to identify the sources of elements in PM2.5. The results revealed that the elements originated mainly from traffic emissions, coal combustion, pyrometallurgical processes, and crustal sources. Spatially, the concentrations of elements were generally higher in several rapidly growing locations, and the enrichment factors (EFs) for most elements were much higher at the northern sites than those at the southern sites, suggesting that the air quality in the northern part of the study area was strongly affected by anthropogenic activity. Backward wind trajectory analysis during the sampling period indicated that the concentrations of elements in PM2.5 in the WTS region were greatly impacted by dust particles transported from Northern China in spring. ► Elements in PM2.5 among the city group in the Western Taiwan Strait were studied. ► PCA and CA results indicated that multi-sources contributed to the elements. ► Elements were abundant in several fast growing locations. ► Elements were much highly enriched at the northern sites than the southern sites. ► Air masses from the Northern China might elevate the element concentration.