Pollution Characteristics of Heavy Metals in PM2.5 and Their Human Health Risks Among the Coastal City Group Along Western Taiwan Straits Region, China

Abstract

PM2.5 samples were collected from 11 sampling sites in the coastal city group along western Taiwan Straits region, China, and these heavy metal elements (Zn, Cu, Pb, Ni, Cr, As) were detected using particle-induced X-ray emission (PIXE) method. The pollution characteristics, enrichment factors and source apportionment of heavy metals in PM2.5 were analyzed, and furthermore, their human health risks were determined. The result showed concentration distribution was obviously different between PM2.5 and heavy metals in the city group, for the main sources (e.g. construction dust and ground dust) for PM2.5 were not the main contribution to these heavy metals. The enrichment factors of Zn, Cu, Pb, Mn, Ni, Cr, As exceeded 10, which suggested these metals were enriched and significantly impacted by anthropogenic pollution. Three main groups of heavy metals in PM2.5 were identified by principal component analysis (PCA-MLR), such as coal combustion and traffic emissions (70.59%), multiple sources (coal and oil combustion, pyrometallurgical process, 17.55%) and other industry (11.86%). The risk levels for carcinogenic heavy metals (Ni, Cr, As) and non-carcinogenic heavy metals (Zn, Cu, Pb, Mn) were lower than the average level of risk acceptance (10-6), which suggested these heavy metals did not cause harm to human health in these cities.