寿光土壤中多环芳烃的污染特征及风险评估

以山东省寿光市为研究区域,采集了39个土壤样品,分析了26种PAHs的含量.结果表明,26种多环芳烃的浓度范围为120~1486μg/kg,平均值为(415±312)μg/kg.16种优控PAHs的浓度范围为84~1076μg/kg,平均值为(289±211)μg/kg.与我国其他区域非点源污染土壤相比,寿光市土壤中PAHs含量处于中等水平.采用克里格(Kriging)插值方法对寿光市土壤中PAHs的空间分布特征进行预测发现,该市PAHs高污染区位于东部开发区和西部工业园,高环与低环PAHs在空间分布上有明显差异.主成分分析结果显示,该市土壤中PAHs有3个主要来源,分别为液体化石燃料燃烧源、石油源以及煤燃烧源,其对主要来源的贡献率分别为44.7%、31.7%和23.6%.相关性分析表明,低环和高环PAHs与土壤有机质含量均显著相关,但低环PAHs的相关系数明显高于高环PAHs,表明低环PAHs更容易受到土壤中有机质的影响,而高环PAHs则受控于近距离沉降.对照荷兰的土壤管理标准,寿光市土壤中Flt和Phe超标较严重,TEQBaP以及致癌风险计算结果表明,寿光市土壤PAHs处于较低风险水平.

Spatial distribution and risk assessment of polycyclic aromatic hydrocarbons in soils of Shouguang City,North China

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in 39farmland soil samples collected from Shouguang City. The concentrations ranged from 120 to 1486 μg/kg averaged (415 ± 312) μg/kg] for the 26 PAHs and from 84 to 1076 μg/kg averaged (289 ± 211) μg/kg] for the 16PAHs. The PAH levels in Shouguang farmland soils were generally moderate compared to those in soils with non-point sources in China. Kriging interpolation map showed two highly contaminated areas that were located in the two industrialized areas in the eastern and western parts, respectively. Moreover, high-molecule weight and low-molecule weight PAHs (HWPAHs and LWPAHs) showed distinct spatial distributions in the soil. Principal components analysis indicated that combustion of fossil fuel, petroleum, and coals burning were the three primary sources of PAHs in soils of Shouguang City, with contributions of 44.7%, 31.7% and 23.6%, respectively. HWPAHs and LWPAHs were both correlated significantly with soil organic matter (SOM), but the correlation was more significant for LWPAHs. This suggested that LWPAHs were more susceptible to SOM than HWPAHs, which were easily controlled by local deposition. Flt and Phe in most soil exceeded the soil quality guidelines of Netherland. The incremental lifetime cancer risk associated with the PAHs in the soils in this region was basically low.