深圳市大气中多环芳烃的污染特征与来源识别

利用大流量主动采样器于2009年12月~2010年1月及2010年6月,分冬季与夏季两批次对深圳市13个点位进行大气样品采集,检测其气相及颗粒相中总的多环芳烃(PAHs)浓度.结果表明,冬季深圳市大气中总PAHs的浓度为17.9~92.3ng/m3,平均值为45.3ng/m3;夏季总PAHs浓度范围为8.64~96.3ng/m3,平均值为32.2ng/m3.两个季节PAHs单体中均以3~4环为主,占总浓度的75%以上;单个组分与总量的相关性分析表明,夏季明显优于冬季.来源分析表明,冬季大气中PAHs来源比夏季更为复杂,通过特征分子比值法推断冬季PAHs主要来源于石油源、燃煤、机动车尾气排放;夏季主要来源于机动车尾气排放.利用毒性当量因子法和致癌风险评价其污染水平和毒性风险,结果表明深圳市大气中PAHs污染与国内部分城市相比,处于较低水平.

Pollutant characterization and source identification of polycyclic aromatic hydrocarbons (PAHs) in Shenzhen atmosphere

Air samples of thirteen sampling sites in Shenzhen were collected by the active high volume air sampler during December 2009 to January 2010 and June 2010. The PAHs in both air phase and particulates phase were analyzed, and the results showed that the concentrations of ∑PAHs in winter ranged from 17.9 to 92.3ng/m3, with average concentration of 45.3ng/m3, whereas in summer, the ∑PAHs concentrations scanned from 8.64 to 96.3ng/m3, with average concentration of 32.2ng/m3. The three to four rings PAHs occupied large proportion in all samples, which accounted for at least 75%. The concentration correlation analysis of monomers and ∑PAHs in two sampling periods demonstrated that the correlation in summer was better than that in winter. And the PAHs pollutants resources in winter were more complex than that in summer. The conclusion were also proved by the diagnostic ratio method, the oil and coal combustion, moter vehicles emission were the main resources in winter, but the main source in summer was only the motor vehicles emission. The toxic equivalence factor (TEF) and canceraganic risk assessment showed that the pollution of PAHs in Shenzhen city was still under a low level in comparison with other cities in China.