Distribution, sources, and potential risk of polycyclic aromatic hydrocarbons in soils from an industrial district in Shanxi, China.

Abstract

Concentration, composition profile, orientation distribution, sources, and potential risks of 16 polycyclic aromatic hydrocarbons (PAHs) were analyzed in 76 surface (0-25cm) soil samples collected from the Changzhi industrial district in July 2014 using a gas chromatography mass spectrometer (GC-MS QP2010 Ultra) system. The composition patterns of the PAHs were dominated by the presence of four-ring PAHs (average 42.9%), followed by three-ring (average 25.9%), five-ring PAHs (average 25.6%), two-ring PAHs (average 5.03%), and lastly, six-ring PAHs (average 0.641%). Source apportionment of the soil PAHs was also performed by the diagnostic ratios, principal component analysis (PCA), and coefficient of divergence (CD) analysis indicated signatures of PAHs sources (including incineration, coal/wood combustion, and vehicular exhaust emission). The total concentration of 16 PAHs (∑16PAHs) found in the roadsides soils (RS) ranged from 2197 to 25,041μgkg-1, with an arithmetic mean value of 12,245μgkg-1; followed by the village soils (VS), which ranged from 2059 to 21,240μgkg-1, with a mean of 8976μgkg-1; and lastly, the agricultural soils (AS), which ranged from 794 to 16,858μgkg-1, with a mean of 3456μgkg-1. According to the numerical effect-based soils quality guidelines of Maliszewska-Kordybach, the levels of PAHs in the sampled industrial areas range from high to heavy contamination. The values of total benzo[a]pyrene toxicity equivalent values (∑Bapeq16PAHs) in the sample areas ranged from 0.087 to 3611μgkg-1 with an average of 969μgkg-1. According to the soil quality guidelines of Canada, values found in the highest range (100μgkg-1), which are equal to those of ∑Bapeq16PAHs found in the industrial area samples, will exert adverse biological effects. The results of this research could potentially be useful for local governments to control toxicity exposure, promote actions to alleviate PAHs contamination, and to manage human health at both work and industrial areas.