海口市秋冬季节PM_(2.5)中多环芳烃含量特征

Distribution Characteristics of PAHs in PM_(2.5) during Autumn and Winter in Haikou

在海口市布设2个采样点,于2014年秋冬季节采集大气PM_(2.5)样品,采用超声萃取和GC/MS分析了PM_(2.5)中优先控制的16种PAHs,探讨了其含量分布特征,对PAHs健康风险进行了评价,并运用比值法定性解析其可能来源。研究结果表明:2个采样点秋冬季节PAHs平均质量浓度为4.825、6.771 ng/m3,其中以Pyr浓度最高;PM_(2.5)中以分子量大的化合物为主,其中4环PAHs所占比率最高,达到38.9%以上;秋季和冬季BEQ日均值分别为0.577、0.691 ng/m^3,均低于国内外BaP限值标准;比值法分析PM_(2.5)中PAHs来源,最主要的贡献源为机动排放车,同时兼有木材燃烧源的特征。

Atmospheric PM2.5samples were collected at two sites in Haikou autumn and winter of 2014. 16 types of priority controlled polycyclic aromatic hydrocarbons（PAHs） in PM2.5samples were measured by ultrasonic extraction and analyzed by GC/MS method to discuss distribution characteristics. The health degree of risk was evaluated and the possible sources were analyzed by ratio method. The results showed that average concentration of PAHs in autumn and winter was 4.825ng/m^3,6.771 ng/m^3 with the highest concentration of Pyr. PAHs with higher molecular weight were the dominant components in Haikou,and 4 rings PAHs had the greatest proportion,which reached 38.9% at least. BEQ of daily mean value in autumn and winter was 0.577 ng/m^3,0.691 ng/m^3 respectively,which was lower than the controlled Ba P by China and WHO.According to the diagnostic ratios of PAHs from typical sources,vehicle exhaust and wood combustion were the dominant source of PAHs in PM2.5during autumn and winter in Haikou.