武汉市青山区冬季PM_(2.5)中PAHs污染特征及健康风险评估

Pollution characteristics and risk of polycyclic aromatic hydrocarbons in PM_(2.5) from Qingshan District of Wuhan during the winter

在湖北省武汉市青山区布设三个采样点,利用智能中流量空气颗粒物采样器采集2013年冬季大气PM2.5样品,共获得PM2.5样品15个,采用气相色谱-质谱联用仪(GC-MS)检测其中16种优控多环芳烃(PAHs)含量,并对PM2.5中PAHs的组成和污染特征、来源进行分析。结果表明,PM2.5中PAHs的浓度呈现工业点>市区点>城郊点的分布特征;对不同环数多环芳烃化合物进行对比分析,发现重环PAHs比重高于轻环,同时重环中4环占较大比重;通过化合物之间比值对PAHs来源进行识别,发现煤的燃烧对武汉市青山区域内PM2.5浓度有较大的贡献率;利用Ba P毒性当量法对PAHs进行健康风险评估,发现武汉市青山区冬季大气PM2.5中PAHs的TEQ除了城郊点低于国家标准限值,其他采样点均在不同程度上高于国家标准限值。

A medium flow, air particulate sampler was used to collect PM2.5 samples in the winter of 2013. Field data for PM2.5 were collected at urban, industrial and rural sites in Qingshan District of Wu- han. Fifteen samples were obtained finally. The composition and characteristics of 16 polycyclic aromatic hydrocarbons （PAHs） in fine particulate matte （PM2.5 ） were analyzed by Gas Chromatography-Mass Spectrometer （GC-MS）. It showed that the PAHs in PM2. 5 displayed the concentration in an order of in- dustrial 〉 urban 〉 suburbs site. Comparing with ring numbers of the PAHs compounds, it can be found that the heavy ring PAHs accounted for higher percentage than the light ring ones in PMz 5 with four rings dominating the heavy rings. Coal burning was found to be the major PAHs source in the Qingshan District by analysis of the ratio of toxic compounds of PAHs. The TEQ method was used for the health risk assess- ment of PAHs. The TEQ in Qingshan District of Wuhan were in the excess of the national standard limits except rural area.