Source identification of polycyclic aromatic hydrocarbons in terrestrial soils in Chile

In this study, a combination of the diagnostic binary ratios of PAHs and multivariate descriptive statistics was applied to identify the sources of PAHs in Chilean terrestrial soils. A total of 15 PAHs from the terrestrial soil of 28 locations in three cities of Chile were chemically characterized using gas chromatography mass spectrometry (GC-MS). The total concentrations of twelve likely carcinogenic PAHs were defined as the sum of Phe, An, Fluo, Pyr, B[a]A, Chry, B[b]F, B[k]F, B[a]P, Ind, D[a, h]A and B[g, h, i]P and ranged from 0.0215 to 4.37 μg g⁻¹ with an arithmetic mean of 0.618 ± 0.911 μg g⁻¹. The levels of these PAHs were classified as moderate to high compared to World Soils (WS). All sampling stations were dominated by high molecular weight PAHs, four-ring (39.1%) and five-ring (29.6%) PAHs were the most abundant groups in the terrestrial soils of Chile. The PAH diagnostic ratios suggested that PAHs are primarily of pyrogenic origin. Further multivariate descriptive statistics (i.e., hierarchical cluster analysis (HCA) and principal components analysis (PCA)) identified pyrogenic combustion as the main emission source of PAH contamination in Chilean terrestrial soils.