Lang Chang, Tao Shu, Zhang Gang, Fu Jiamo, Simonich Staci
Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871, China.
Environ Sci Technol. 2007 Dec 15;41(24):8370-5. doi: 10.1021/es071853v.
The atmospheric outflow of polycyclic aromatic hydrocarbons (PAHs) from Guangdong, China, a region of high PAH emission, was modeled using a potential receptor influence function (PRIF) probabilistic model which was based on a spatially resolved PAH inventory and air mass forward-trajectory calculations. Photochemical degradation and deposition (dry and wet) of PAHs during atmospheric transport were taken into consideration. On average, 48% of the PAHs (by mass) remained in the atmosphere for a transport period of 5 days, staying within the boundary of the source region. The medium molecular weight PAHs (four rings) were predicted to travel longer distances in the atmosphere than the low (three rings) or high molecular weight PAHs (five rings) because they are less photodegradable than the lower molecular weight, gas-phase PAHs and less likelyto undergo wet and dry depositions than the higher molecular weight, particulate phase PAHs. Under the strong influence of the East Asian monsoons in winter, the predominant outflow pattern of PAHs from Guangdong was to the South China Sea and Southeast Asian countries. In summer, PAHs were transported primarily to northern mainland China. Under particular weather conditions in winter, the PAH-containing air masses were lifted by cold fronts or convection and transported toward the Pacific Ocean by westerly winds. In addition to the distinct seasonality in PAH dispersion and outflow, interannual long-term variation in the outflow is likely influenced by El Niño and southern oscillation.
利用基于空间分辨多环芳烃排放清单和空气质量向前轨迹计算的潜在受体影响函数（PRIF）概率模型，对中国广东这个多环芳烃高排放地区的大气多环芳烃排放进行了模拟。模拟过程中考虑了多环芳烃在大气传输过程中的光化学降解和沉降（干沉降和湿沉降）。平均而言，48%的多环芳烃（按质量计）在5天的传输期内仍留在大气中，且停留在源区边界内。预计中等分子量的多环芳烃（四环）在大气中的传输距离比低分子量（三环）或高分子量多环芳烃（五环）更远，这是因为它们的光降解性低于低分子量气相多环芳烃，且与高分子量颗粒相多环芳烃相比，干湿沉降的可能性更小。在冬季东亚季风的强烈影响下，广东多环芳烃的主要流出模式是流向南海和东南亚国家。夏季，多环芳烃主要输送到中国大陆北部。在冬季特定天气条件下，含多环芳烃的气团被冷锋或对流抬升，并通过西风输送到太平洋。除了多环芳烃扩散和流出存在明显的季节性外，流出的年际长期变化可能受厄尔尼诺和南方涛动的影响。
