这项研究是为了表征三种关注健康的醛(甲醛,乙醛,和丙烯醛)在2008年夏季和初秋(6月至10月)的北京中心站点。污染环境中的醛来自主要和次要来源,这限制了这些反应性化合物的控制策略。测量是以前做的,during,以及在北京奥运会之后,研究奥运会期间实施的戏剧性空气污染控制措施是否对三种醛的浓度及其潜在的主要和次要来源产生了影响。甲醛的平均浓度,乙醛和丙烯醛分别为29.3±15.1μg/m3,27.1±15.7μg/m3和2.3±1.0μg/m3,在整个测量期间,在光化学烟雾季节,所有这些都处于世界各地城市测得的浓度范围的高端。与奥运会前相比,污染控制期间甲醛和丙烯醛增加,跟随温度的变化,并且与臭氧和通过主成分分析(PCA)确定的次要形成因子显着相关。相比之下,与奥运会前相比,奥运会空气污染控制期间乙醛的平均浓度有所降低,并且与当地排放源排放的几种污染物显着相关(例如,NO2,CO,和PM2.5)。乙醛也与主要排放源密切相关,包括通过PCA确定的植物燃烧和石油燃烧因素。与奥运会前和奥运会期间相比,在奥运会后的采样期间,所有三种醛均较低,可能是由于季节性和区域性影响。我们的发现指出了二次污染物源控制策略的复杂性。
This study was carried out to characterize three
aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a central Beijing site in the summer and early fall of 2008 (from June to October).
Aldehydes in polluted atmospheres come from both primary and secondary sources, which limits the control strategies for these reactive compounds. Measurements were made before, during, and after the Beijing Olympics to examine whether the dramatic air pollution control measures implemented during the Olympics had an impact on concentrations of the three
aldehydes and their underlying primary and secondary sources. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.3±15.1 μg/m3, 27.1±15.7 μg/m3 and 2.3±1.0 μg/m3, respectively, for the entire period of measurements, all being at the high end of concentration ranges measured in cities around the world in photochemical smog seasons. Formaldehyde and acrolein increased during the pollution control period compared to the pre-Olympic Games, followed the changing pattern of temperature, and were significantly correlated with ozone and with a secondary formation factor identified by principal component analysis (PCA). In contrast, acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period and was significantly correlated with several pollutants emitted from local emission sources (e.g., NO2, CO, and PM2.5). Acetaldehyde was also more strongly associated with primary emission sources including vegetative burning and oil combustion factors identified through the PCA. All three
aldehydes were lower during the post-Olympic sampling period compared to the before and during Olympic periods, likely due to seasonal and regional effects. Our findings point to the complexity of source control strategies for secondary pollutants.