According to the most recent update of the WHO (World Health Organization) air quality guidelines, many studies were published that had investigated the effects of air pollution on human health. Particulate matter pollution is nowadays one of the problems of the most concern in great cities, not only because of the adverse health effects, but also for the reducing atmospheric visibility and affect to the state of conservation of various cultural heritages. On a global scale, particulate matter (PM) also influences directly and/or indirectly the Earth's radiation energy balance, and can subsequently impact on global change.
Suspended atmospheric particulate matter, PM10 and PM2.5 (D less then 10 micrometers and D less then 2.5 micrometers, respectively) are today a key issue in contemporary air pollution research. Suspended particles were collected on Pure Teflon and Teflon-coated Quartz filters using MiniVol air samplers (Airmetrics Co. Inc., 5 l/min flow rate) provided with PM10 and PM2.5 cutoff inlets. Mass concentration measurements of suspended particles was determined by weighting of the filters using a semi-micro balance (Sartorius, R 160P), with a minimum resolution of 0.01 mg in a Class 100 clean laboratory.
The elemental composition (Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Pb…) of the aerosol samples, was measured by the atomic absorption spectroscopy method and XRF spectrometry.
Scanning electron microscopy (SEM) coupled with Energy-Dispersive X-ray analysis (EDX) was used for the characterization (size, size distribution, morphology and chemistry of particles) and source apportionment of suspended atmospheric particulate matter. One PM sample per sampling episode was analyzed with the SEM/EDX (JOEL JSM-5300 SEM) according to the US-EPA Guidelines (2002).
Multivariate receptor modeling (PCA, PMF, UNMIX) and air back trajectories analysis were used to identify the main sources. From the statistical properties of air pollutants the level of reduction of particle matter emission sources required to meet the AQS can be estimated. These results may be useful for developing air control strategy in future years.
The SEM photomicrographs of some characteristic particles and their X-ray spectra are presented.