Air Pollution Research Department, National Research Centre, Dokki, Giza, Egypt.
Environ Monit Assess. 2012 Jun;184(6):3593-612. doi: 10.1007/s10661-011-2210-8. Epub 2011 Jul 26.
Atmospheric particulate and gaseous polycyclic aromatic hydrocarbons (PAHs) samples were collected from an urban area in Dokki (Giza) during the summer of 2007 and the winter of 2007-2008. The average concentrations of PAHs were 1,429.74 ng/m(3) in the particulate phase, 2,912.56 ng/m(3) in the gaseous phase, and 4,342.30 ng/m(3) in the particulate + gaseous phases during the period of study. Dokki has high level concentrations of PAH compounds compared with many polluted cities in the world. The concentrations of PAH compounds in the particulate and gaseous phases were higher in the winter and lower in the summer. Total concentrations of PAHs in the particulate phase and gaseous phase were 22.58% and 77.42% in summer and 36.97% and 63.03% in winter of the total (particulate + gaseous) concentrations of PAHs, respectively. The gaseous/particulate ratios of PAHs concentration were 3.43 in summer and 1.71 in winter. Significant negative correlation coefficients were found between the ambient temperature and concentrations of the total PAHs in the particulate and gaseous phases. The distribution of individual PAHs and different categories of PAHs based on aromatic ring number in the particulate and gaseous phases during the summer and winter were nearly similar, indicating similar emission sources of PAHs in both two seasons. Benzo(b)fluoranthene in the particulate phase and naphthalene in the gaseous phase were the most abundant compounds. Diagnostic concentration ratios of PAH compounds indicate that these compounds are emitted mainly from pyrogenic sources, mainly local vehicular exhaust emissions. Health risks associated with the inhalation of individual PAHs in particulate and gaseous phases were assessed on the basis of its benzo(a)pyrene equivalent concentration. Dibenzo(a,h)anthracene and benzo(a)pyrene in the particulate phase and benzo(a)pyrene and benzo(a)anthracene in the gaseous phase were the greatest contributors to the total health risks. The relative mean contributions of the total carcinogenic activity (concentrations) of all PAHs to the total concentrations of PAHs were 29.37% and 25.15% in the particulate phase and 0.76% and 0.92% in the gaseous phase during the summer and winter, respectively. These results suggest that PAHs in the particulate phase in the ambient air of Dokki may pose a potential health risk.
2007 年夏季和 2007-2008 年冬季，在吉萨的多基（Dokki）城区采集了大气颗粒态和气态多环芳烃（PAHs）样品。研究期间，颗粒相、气相和颗粒+气相中 PAHs 的平均浓度分别为 1429.74ng/m3、2912.56ng/m3和 4342.30ng/m3。与世界上许多污染城市相比，多基的多环芳烃化合物浓度水平较高。颗粒相和气相中的 PAH 化合物浓度在冬季较高，夏季较低。颗粒相和气相中 PAHs 的总浓度分别占颗粒+气相总浓度的 22.58%和 77.42%（夏季）和 36.97%和 63.03%（冬季）。夏季和冬季气相/颗粒相 PAH 浓度比值分别为 3.43 和 1.71。环境温度与颗粒相和气相中总 PAHs 浓度之间存在显著的负相关系数。夏季和冬季颗粒相和气相中基于芳环数的各 PAHs 和不同类别的 PAHs 分布几乎相似，表明两个季节 PAHs 的排放源相似。颗粒相中苯并（b）荧蒽和气相中萘是最丰富的化合物。PAH 化合物的诊断浓度比表明，这些化合物主要来自于燃烧源，主要是当地车辆排放的废气。根据其苯并（a）芘等效浓度，评估了个体 PAHs 在颗粒相和气相中吸入的健康风险。颗粒相中二苯并（a，h）蒽和苯并（a）芘以及气相中苯并（a）芘和苯并（a）蒽是对总健康风险贡献最大的物质。夏季和冬季，颗粒相和气相中所有 PAHs 的总致癌活性（浓度）对总 PAHs 浓度的相对平均贡献率分别为 29.37%和 25.15%和 0.76%和 0.92%。这些结果表明，多基大气环境中颗粒相的 PAHs 可能构成潜在的健康风险。
