包头市居民区积尘中多环芳烃的污染特征及来源解析

Characteristics and sources of polycyclic aromatic hydrocarbons in Baotou residential dust

对46个包头市居民区积尘样品中16种EPA优控多环芳烃的含量、污染特征进行了分析,使用主成分分析法对其来源进行了解析.结果表明,Σ16PAHs介于2868—14218μg·kg^(-1)之间,平均值为7404μg·kg^(-1).以Ace、Phe和Flu等3—4环多环芳烃为主,占Σ16PAHs的48.0%—86.4%,平均占Σ16PAHs的74.5%.与国内外研究区域相比,包头市积尘样品中PAHs含量较高,Σ16PAHs在整个城市范围内都有比较严重的污染、Ba P毒性当量在青山区西北部和青山区东南部较高、Ba P含量在昆都伦区西部和东河区东部较高.总毒性当量浓度介于231.8—3102μg·kg^(-1)之间,平均为614.0μg·kg^(-1),7种致癌PAHs毒性当量浓度介于226.8—3096μg·kg^(-1)之间,平均为604.8μg·kg^(-1).7种致癌PAHs毒性当量浓度占16种PAHs毒性当量浓度的98.1%,其中Bk F、Ba P和DBA为主要对PAHs总毒性当量浓度有贡献的PAHs,占总PAHs毒性当量浓度的88.8%.主成分分析表明,包头居民区积尘中多环芳烃主要来源为汽油机动车排放源、燃煤源、生物质燃烧源、柴油车排放源,分别贡献27.1%、26.4%、10.0%、8.5%.

Contents of sixteen polycyclic aromatic hydrocarbons（PAHs） in 46 residential dust samples collected from Baotou were determined,and the major sources of PAHs were apportioned by principal component analysis（PCA）. The Σ16PAHs ranged from 2868 to 14218 μg·kg^-1,with a mean value of 7404 μg·kg^-1. 3-ring（Ace,Phe） and 4-ring PAHs（Flu） accounted for 48. 0%—86.4% of Σ16PAHs,with an average of 74.5%. Compared to other major cities around the world,the concentration of ∑16PAHs in the residential dust of Baotou was higher. Higher levels of toxic equivalent concentrations（TEQs） were mainly distributed in the northwest and southwest ofQingshan districts. Higher levels of Ba P were detected in the west of Kundulun districts and east of Donghe districts. The TEQs of PAHs in the residential dust ranged from 231.8—3102 μg·kg^-1,with a mean value of 614.0 μg·kg^-1. The TEQs of seven carcinogenic PAHs in the residential dust ranged from 226.8—3096 μg·kg^-1μg·kg^-1,with a mean value of 604.8 μg·kg^-1,accounting for 98.1% of total TEQs. Bk F,Ba P and DBA were the predominant PAHs and accounted for 88.8% of the seven carcinogenic PAHs. Principal component analysis（PCA） indicated that gasoline auto emission,coal combustion,biomass combustion and diesel auto emission were the major sources of polycyclic aromatic hydrocarbons in Baotou residential dust,contributing 27.1%,26.4%,10.0% and 8.5% of the total PAHs.