Polycyclic Aromatic Hydrocarbons in Surface Soils of Kunming, China: Concentrations, Distribution, Sources, and Potential Risk

Abstract

The concentrations, distribution, possible sources, and potential risk of polycyclic aromatic hydrocarbons (PAHs) in surface soils were studied in Kunming, which is situated in a lake basin of the Yunnan-Guizhou plateau. 15 PAHs were analyzed in 40 surface soil samples (0-5 cm layer) collected from six types of land uses in the Kunming urban area. Meanwhile, the potential sources of PAHs in surface soils of Kunming were investigated by PAH composition ratios, isomer ratios, and principal component analysis (PCA). The total concentrations of 15 PAHs ranged from 101.64 to 6,208.25 ng/g (dry weight basis). The concentrations in different land uses increased in an order as: green space (541.43 ng/g) < education area (756.49 ng/g) < business area (810.17 ng/g) < residential area (1,034.36 ng/g) < industrial area (1,166.79 ng/g) < roadside greens (2,146.76 ng/g). The results of sources identification suggested that PAHs in surface soils of the Kunming urban area were greatly affected by combustion activities which came mainly from coal combustion and vehicular traffic. In addition, the toxic equivalency factors (TEFs) were used to estimate benzo[a]pyrene-equivalent concentration in surface soils of Kunming, and the risk level of PAHs in Kunming's urban surface soils was low as a whole.

Sources and cancer risks assessment of polycyclic aromatic hydrocarbons in particulate matter and surface soils in Kunming, China

“…Similarly, FLA (13.85%) was the most abundant compound in surface soil samples, followed by PYR (13.77%), PHE (12.85%), CHR (11.61%), ANT (8.87%) and BbF (7.86%). FLA, PYR, CHR, PHE and BbF were the abundant compounds both in PM and surface soil samples, which was similar with earlier paper on the profiles of PAHs in Kunming (Lin et al, 2013;Yang et al, 2015;Zhao et al, 2014). Obviously, the proportions of FLA absorbed in all measured samples were relatively higher than that of other compounds.…”

“…The daily samples collected at each site were extracted and processed separately, and they were extracted cumulatively and a single value was obtained for each site. Details of the analysis of PAHs have been described previously (Lin et al, 2013;Yang et al, 2015). Before analysis, the filters and surface soils were lyophilised for 72 h using an Eyela FDU-1200 freeze drier (Tokyo, Japan).…”

“…It is significance to notice the pollution characteristics of PAHs in this city. Earlier papers on the results of PAHs in Kunming were focused on TSP and surface soils, showed that PAHs were detected both in TSP and surface soils (Lin et al, 2013;Yang et al, 2015). However, there is a lack of data documenting PM 2.5 -bound PAHs in Kunming, which can better understand the fate of PAHs pollution and assess the potential human health risks.…”

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

“…If naphthalene is assumed not to contribute significantly to the overall ecological impact of ∑ 16 PAH, the ∑ 15 PAH data acquired in the present study can still be used to characterize soil contamination (Motelay-Massei et al, 2004;Maliszewska-Kordybach et al, 2008;Lin et al, 2013). Based on this classification, 80.3% of the soils investigated in the present study can be considered being non-contaminated, 13.1% weakly contaminated, 3.1% contaminated, and 3.5% as heavily contaminated by PAHs.…”

Study of polycyclic aromatic hydrocarbons (PAHs) in soil samples from Al-Ahdab oil field in Waset Region, Iraq

“…Honda et al (2007) have analyzed 21 PAHs in soil samples collected from particular sites in Japan from 1959-2005 and found the total concentration in the range of 53-2180 mg/kg. Lin et al (2013) have analyzed forty surface soil samples (0-5 cm depth) from Kunming/China and found the total concentration of 15 PAHs was between 102 and 6208 mg/kg. Man et al (2013) have evaluated 55 soil samples from different land use types in Hong Kong/China on human cancer risk related to PAHs.…”