Kim Eugene, Hopke Philip K
Center for Air Resource Engineering and Science,Clarkson University, Potsdam, NY, USA.
J Air Waste Manag Assoc. 2008 Oct;58(10):1328-40.
Ambient PM2.5 (particulate matter less than 2.5 microm in aerodynamic diameter) in the northwestern United States and Alaska is dominated by carbonaceous compounds associated with wood burning and transportation sources. PM2.5 source characterization studies analyzing recent PM2.5 speciation data have not been previously reported for these areas. In this study, ambient PM2.5 speciation samples collected at two monitoring sites located in the northwestern area, Olympic Peninsula, WA, and Portland, OR, and one monitoring site located in Anchorage, AK, were characterized through source apportionments. Gasoline vehicle, secondary sulfate, and wood smoke were the largest sources of PM2.5 collected at the Anchorage, Olympic, and Portland monitoring sites, respectively. Secondary sulfates showed an April peak at Anchorage and a November peak at Portland that are likely related to the increased photochemical reaction and long-range transport in Anchorage and meteorological stagnation in Portland. Secondary nitrate at the Olympic site showed a weak summer high peak that could be caused by seasonal tourism in the national park. Backward trajectories suggested that the elevated aged sea salt concentrations at the Portland monitoring site could be regional transport of sea salt that passed through other contaminated air sheds along the coast. Oil combustion emissions that might originate from ships and ferries were observed at the Olympic monitoring site.
美国西北部和阿拉斯加的环境细颗粒物（空气动力学直径小于2.5微米的颗粒物）主要由与木材燃烧和交通源相关的碳质化合物构成。此前尚未有针对这些地区分析近期细颗粒物成分数据的细颗粒物源特征研究报告。在本研究中，通过源解析对在位于华盛顿州奥林匹克半岛和俄勒冈州波特兰的两个西北部监测点以及阿拉斯加安克雷奇的一个监测点采集的环境细颗粒物成分样本进行了特征分析。汽油车、二次硫酸盐和木烟分别是在安克雷奇、奥林匹克和波特兰监测点采集的细颗粒物的最大来源。二次硫酸盐在安克雷奇呈现4月峰值，在波特兰呈现11月峰值，这可能分别与安克雷奇光化学反应增加和长距离传输以及波特兰的气象停滞有关。奥林匹克监测点的二次硝酸盐呈现微弱的夏季高峰，这可能是由国家公园的季节性旅游导致的。后向轨迹表明，波特兰监测点老化海盐浓度升高可能是海盐通过沿海其他受污染气团的区域传输造成的。在奥林匹克监测点观测到了可能源自船舶和渡轮的石油燃烧排放。
