砣矶岛背景站PM_(2.5)中多环芳烃的来源及健康风险

对2011年11月—2013年1月在砣矶岛国家大气背景站采集的75个大流量PM2.5样品的多环芳烃含量和组成进行分析。结果表明,砣矶岛16种优控多环芳烃(Σ16PAHs)的总质量浓度为4.7~41 ng/m3(平均(17±10)ng/m3),季节上表现为冷季高、暖季低的变化趋势。综合气流轨迹分析、分子标志物、特征化合物比值、潜在源贡献指数分析等方法发现,夏季山东半岛的生物质燃烧是主要污染源;冷季主要受京津冀及周边地区的燃煤排放和复合污染输出的共同影响。砣矶岛PAHs的总毒性当量(Ba Peq)在0.54~8.2 ng/m3之间,平均水平为2.8 ng/m3,39%以上的样品超过国标阈值,说明环渤海地区PAHs健康风险存在区域性。

Potential sources and health risk of PM2.5-bounded PAHs at the background site at Tuoji Island

Concentration and composition of polycyclic aromatic hydrocarbons (PAHs) were determined for 75 HiVol PM_2.5 samples collected at the national station for background atmospheric monitoring at Tuoji Island from Nov. 2011 to Jan. 2013. The results showed that the total concentration of the 16 USEPA priority PAHs (Σ16PAHs) ranged from 4.7 to 41 ng/m³, with an average value of (17±10) ng/m³, and high PAHs concentrations occurred in cold seasons while low concentrations in warm seasons. An integrated approach of air mass back trajectories, molecular tracers, isomer ratios of PAHs and potential source contribution function analysis was used to identify potential sources. It is shown that biomass burning in Shandong Peninsula during summer is the main PAH source while the outflow of coal combustion and mixed emissions from Jing-Jin-Ji and adjacent areas contributes a high PAH level in cold season. The total toxic equivalent of PAHs (BaPeq) at this site ranges from 0.54 to 8.2 ng/m³, with an average of 2.8 ng/m³. Furthermore, the BaPeq levels in 39% of the total samples exceed the national standard of China, indicating the regional characteristic of PAH health risk in the Bohai Rim.