滹沱河冲洪积扇地下水中多环芳烃的污染特征

为调查滹沱河冲洪积扇地下水中多环芳烃（PAHs）的污染状况，采用气相色谱-质谱法对该区16种US EPA优先控制的PAHs进行了分析，并对PAHs的污染水平，空间分布，来源与饮水健康风险进行了调查与评估.结果表明，51个点位中仅有2个点位未检出PAHs， PAHs的浓度范围为未检出~334.3ng/L，平均值为58.0ng/L，低于国内报道的其他地区的污染水平.研究区岗黄水库之间河谷裂隙孔隙水单元（G1），滹沱河冲洪积扇扇顶部孔隙水单元（G2），滹沱河冲洪积扇扇中部孔隙水单元（G3）3个水文地质单元PAHs平均浓度分别为215.2ng/L， 9.8ng/L，9.2ng/L， 其中G1以3~4环PAHs为主，而G2， G3以2~3环PAHs为主.分子比值法污染源解析表明，G1单元地下水PAHs污染源主要为煤与生物质燃烧，而G2， G3单元污染源主要为石油制品.采用US EPA推荐的方法对研究区地下水饮水健康风险进行评价，发现研究区G1单元PAHs饮水终生致癌风险平均值为2.1×10^-5，超过可接受水平，应当引起关注.

Pollution characteristic of polycyclic aromatic hydrocarbons in the groundwater of Hutuo River Pluvial Fan

In order to investigate the pollution status of polycyclic aromatic hydrocarbons (PAHs) in the groundwater of Hutuo River Pluvial Fan, the 16 US EPA priority control PAHs in the groundwater of this region were analyzed by gas chromatography-mass spectrometry. The occurrence, distribution characteristics, sources and their potential probabilistic carcinogenic risk through drinking water were also assessed in this present study. No PAHs were detected in only two water samples among the 51sample sites. The concentration of the ∑PAHs was ranged from not detectable to 333.4ng/L and with the average value of 58.0ng/L. It was less than that of other reported groundwater regions in China. The average concentration of PAHs for the Gangnan reservoir valley fracture pore water unit (G1), the pore water unit of the top of Hutuo River Pluvial fan (G2) and the pore water unit of the middle part of Hutuo River Pluvial fan (G3) was 215.2ng/L, 9.8ng/L, 9.2ng/L, respectively. The 3~4 ring PAHs was dominant in the total PAHs in G1unit, while the 2~3 ring PAHs was dominant in G2 and G3 units. The source pollution of PAHs in this region was appointed by the molecular ratio and it showed that the coal and biomass burning was predominant source for G1unit, whereas the petroleum products were predominant source for G2 and G3 units. The health risk of drinking groundwater in the study area was evaluated by the recommended method by US EPA and the average cancer risk of G1was over acceptable level (2.1×10^-5), which indicated that the quality of groundwater in G1should be pay more attention by government.