Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong Province, 264003, China.
Environ Monit Assess. 2011 Jan;172(1-4):235-47. doi: 10.1007/s10661-010-1330-x. Epub 2010 Feb 10.
Shanghai is the largest industrial and commercial city in China, and its air quality has been concerned for several years. However, scarce study had been made on the seasonal levels of atmospheric polycyclic aromatic hydrocarbons (PAHs), together with their gas-particle partitioning and potential emission sources. Based on an intensive sampling campaign at urban and suburban areas in Shanghai during four seasons of 2005-2006, this study presented the measurement of PAH concentrations in both particulate and gaseous phases, as well as seasonal and spatial variability. The results showed that the annual PAH levels (gas + particle) were 167 ± 109 ng m⁻³ at the urban site and 216 ± 86.5 ng m⁻³ at the suburban site. Gaseous PAHs (>70%) dominated the total PAH mass at both sites, while particulate PAHs contributed more than 90% of the toxic power according to benzo(a)pyrene-equivalent carcinogenic parameter. Different seasonal trend of PAH concentrations was observed between the two sites, and it may be explained by complicated factors such as sampling heights, local/regional emission sources, and climatic conditions. The gas-particle partitioning of PAHs in all samples was calculated, and strong linear correlations between log K (p) and log P(L)° were observed, with shallower slopes (m(r)) at the suburban site than the urban one and in warm season than the cold months, indicating the different equilibrium conditions of PAHs in spatial and seasonal scales in Shanghai. The slope (m(r) = - 0.96) and correlation coefficient (R² = 0.81) for four-ring PAHs were closest to theoretical equilibrium conditions among compounds with various aromatic rings. Finally, the potential PAH sources were estimated based on principal factor analysis with multiple linear regressions. Ground volatilization dominated the PAH pollutions at both sites, while vehicles and coal consumption were the other main emission sources, which totally contributed 32.0% (suburban) to 49.2% (urban) of PAH mass in Shanghai atmosphere. The effects of wood and biomass burning were also detected, but their contributions to PAHs were negligible.
上海是中国最大的工商业城市，其空气质量多年来一直受到关注。然而，对于大气多环芳烃（PAHs）的季节性水平及其气固分配和潜在排放源，鲜有研究。本研究基于 2005-2006 年四个季节在上海市区和郊区的密集采样，提供了颗粒物相和气相中 PAH 浓度的测量结果，以及季节性和空间变异性。结果表明，市区和郊区大气中 PAHs（气+粒）的年平均浓度分别为 167±109ng/m³和 216±86.5ng/m³。在两个采样点，气态 PAHs（>70%）均占总 PAH 质量的主导地位，而根据苯并[a]芘等效致癌参数，颗粒物相 PAHs 贡献了超过 90%的毒性。两个采样点的 PAH 浓度具有不同的季节性趋势，这可能与采样高度、局部/区域排放源和气候条件等复杂因素有关。对所有样品的 PAHs 气固分配进行了计算，发现 log K（p）与 log P（L）°之间存在很强的线性相关性，且在郊区采样点的斜率（m(r)）比市区采样点和温暖季节的斜率更平缓，这表明在上海的空间和季节尺度上，PAHs 的平衡条件存在差异。四环 PAHs 的斜率（m(r) = - 0.96）和相关系数（R² = 0.81）与各芳香环化合物的理论平衡条件最为接近。最后，采用主因子分析与多元线性回归相结合的方法，估算了潜在的 PAH 源。地面挥发作用主导了两个采样点的 PAH 污染，而机动车和煤炭消耗是其他主要的排放源，它们在上海大气中 PAH 质量的总贡献率分别为 32.0%（郊区）和 49.2%（市区）。还检测到了木材和生物质燃烧的影响，但它们对 PAHs 的贡献可以忽略不计。
