Association of soil polycyclic aromatic hydrocarbon levels and anthropogenic impacts in a rapidly urbanizing region: Spatial distribution, soil–air exchange and ecological risk

Utility of soil linear alkylbenzenes to assess regional anthropogenic influences with special reference to atmospheric transport

“…Apparently, the spatial distribution pattern of ΣLAB levels indicated greater anthropogenic impacts on the terrestrial environment of the central PRD than the other three regions, and the central PRD may have served as an important source of LABs found in remote areas. This spatial pattern of soil LABs was similar to that of soil PAHs with higher concentrations of both Σ 28 PAH and Σ 15 PAH in the central PRD than in other three geographic regions (Wei et al, 2014b), indicating that the concentrations of both LABs and PAHs were well reflective of anthropogenic influences on the regional terrestrial environment.…”

“…(r 2 = 0.06, p b 0.05; Fig. S3a) possibly implied that soil organic matter was not the key factor controlling the distribution of hydrophobic compounds in soils, which was also corroborated by the poor correlation between TOC and PAHs (Wei et al, 2014b). Besides, a weak relationship between the concentrations of ΣLAB and anthropogenic PAHs (Σ 15 PAH) (Wei et al, 2014b) (r 2 = 0.18, p b 0.05; Fig.…”

“…Furthermore, this industrial soil was also enriched with TOC (25.7%) and PAHs (21,000 and 12,000 ng/g for Σ 28 PAH and Σ 15 PAH, respectively) (Wei et al, 2014b). Hence, the soil sample was probably contaminated by point sources (e.g., wastewater from paper mills and petroleum industry (Wei et al, 2014b)), and can be treated as a point-source soil. As a result, it is reasonable to exclude this sample from significant difference tests and Kriging interpolation for spatial distribution.…”

“…Our previous study (Wei et al, 2014b) utilized soil polycyclic aromatic hydrocarbons (PAHs) to elucidate anthropogenic impacts on the terrestrial environment of a large watershed in South China, the Pearl River Delta (PRD; Fig. S1 of the Supplementary data; "S" indicates tables and figures in the Supplementary data thereafter), and the central PRD was found to have become a secondary source of PAHs to the adjacent areas through atmospheric transport.…”

“…The procedures for soil sampling design and collection were detailed previously (Wei et al, 2014b). Briefly, a total of 224 surface soil samples were collected between December 2009 and March 2010 in the PRD and adjacent areas from six land-use types, i.e., industry, agriculture, drinking water source, landfill, residency, and forestry (Fig.…”