Concentration and Photochemistry of PAHs, NPAHs, and OPAHs and Toxicity of PM2.5 during the Beijing Olympic Games

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• 作者：Wentao Wang ; Narumol Jariyasopit ; Jill Schrlau ; Yuling Jia ; Shu Tao ; Tian-Wei Yu ; Roderick H. Dashwood ; Wei Zhang ; Xuejun Wang ; Staci L. Massey Simonich
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：August 15, 2011
• 年：2011
• 卷：45
• 期：16
• 页码：6887-6895
• 全文大小：1025K
• 年卷期：v.45,no.16(August 15, 2011)
• ISSN：1520-5851

文摘

Atmospheric particulate matter with diameter <2.5 um (PM_2.5) was collected at Peking University (PKU) in Beijing, China before, during, and after the 2008 Olympics and analyzed for black carbon (BC), organic carbon (OC), lower molecular weight (MW < 300) and MW302 Polycyclic Aromatic Hydrocarbons (PAHs), nitrated PAHs (NPAHs) and oxygenated PAHs (OPAHs). In addition, the direct and indirect acting mutagenicity of the PM_2.5 and the potential for DNA damage to human lung cells were also measured. Significant reductions in BC (45%), OC (31%), MW< 300 PAH (26鈥?3%), MW 302 PAH (22鈥?7%), NPAH (15鈥?8%), and OPAH (25鈥?3%) concentrations were measured during the source control and Olympic periods. However, the mutagenicity of the PM_2.5 was significantly reduced only during the Olympic period. The PAH, NPAH, and OPAH composition of the PM_2.5 was similar throughout the study, suggesting similar sources during the different periods. During the source control period, the parent PAH concentrations were correlated with NO, CO, and SO₂ concentrations, indicating that these PAHs were associated with both local and regional emissions. However, the NPAH and OPAH concentrations were only correlated with the NO concentrations, indicating that the NPAH and OPAH were primarily associated with local emissions. The relatively high 2-nitrofluoranthene/1-nitropyrene ratio (25鈥?6) and 2-nitrofluoranthene/2-nitropyrene ratio (3.4鈥?.8), suggested a predominance of photochemical formation of NPAHs through OH-radical-initiated reactions in the atmosphere. On average, the 鈭慛PAH and 鈭慜PAH concentrations were 8% of the parent PAH concentrations, while the direct-acting mutagenicity (due to the NPAH and OPAH) was 200% higher than the indirect-acting mutagenicity (due to the PAH). This suggests that NPAH and OPAH make up a significant portion of the overall mutagenicity of PM_2.5 in Beijing.