Arrizza L, De Berardis B, Paoletti L
Centro di Microscopia Elettronica dell'Università dell'Aquila, Roio Poggio, L'Aquila.
Med Lav. 2003 May-Jun;94(3):259-64.
Among the atmospheric pollutants detectable in the environment, the inhalable airborne particulate (PM10) is regarded with increasing concern. Indeed a number of epidemiological studies support the correlation between both acute and chronic adverse health effects and the presence of PM10 levels even lower than the WHO guide lines. Despite these epidemiological findings, it is yet unclear and still widely debated which characteristics of particulate matter are responsible for the observed health effects. The identification of one or more components of PM10 related to the health effects observed in the urban population is a research subject of primary importance for the coming years.
The aim of the present study was to characterise from a physical-chemical point of view the "coarse" (PM10-2.1) and the "fine" (PM2.1) fractions of the airborne particulate matter (PM10) sampled in three different sites dissimilar with regard to the weather conditions, the residential density and industrial activities.
The particles were collected by an eight-stage cascade impactor (Andersen particle fractionating sampler) with a pre-separator stage able to remove particles with aerodynamic diameter > 10 microns. Analysis of the particle samples was performed by a scanning electron microscopy (SEM) equipped with a thin-window system for X-ray microanalysis by energy dispersion spectrometry.
The Hierarchical Cluster Analysis (HCA) of the analytical data revealed the presence of seven different particulate types (particle clusters) in the sampling sites: C-rich particles (cluster 1); Ca and Mg carbonates (cluster 2); Ca sulphates (cluster 3); silica particles (cluster 4); silicates (cluster 5); Fe-rich particles (cluster 6); metal compounds (cluster 7).
Data obtained in this study demonstrated a significant correlation between the "coarse" fraction (PM10-2.1) composition and the characteristics of the sampling site. On the contrary the "fine" fraction (PM2.1) composition showed an unexpected uniformity in all the environments.
在环境中可检测到的大气污染物中，可吸入空气颗粒物（PM10）日益受到关注。事实上，多项流行病学研究证实，即使PM10水平低于世界卫生组织指导标准，也会对健康产生急慢性不良影响。尽管有这些流行病学研究结果，但目前尚不清楚且仍存在广泛争议的是，颗粒物的哪些特性会导致所观察到的健康影响。确定与城市人群中观察到的健康影响相关的PM10的一种或多种成分，是未来几年至关重要的研究课题。
本研究的目的是从物理化学角度对在三个天气条件、居住密度和工业活动不同的地点采集的空气颗粒物（PM10）的“粗颗粒”（PM10-2.1）和“细颗粒”（PM2.1）部分进行表征。
使用八级串联撞击器（安德森颗粒分级采样器）收集颗粒，该采样器带有一个预分离阶段，能够去除空气动力学直径>10微米的颗粒。通过配备薄窗系统的扫描电子显微镜（SEM）对颗粒样品进行分析，该系统用于能量色散光谱法的X射线微分析。
分析数据的层次聚类分析（HCA）显示，采样点存在七种不同的颗粒类型（颗粒簇）：富碳颗粒（簇1）；碳酸钙和碳酸镁（簇2）；硫酸钙（簇3）；二氧化硅颗粒（簇4）；硅酸盐（簇5）；富铁颗粒（簇6）；金属化合物（簇7）。
本研究获得的数据表明，“粗颗粒”部分（PM10-2.1）的组成与采样点的特征之间存在显著相关性。相反，“细颗粒”部分（PM2.1）的组成在所有环境中均表现出意外的一致性。
