Suchergebnisse

Airborne particulate matter - especially aerosols, its origin, its impact on our environment, and its properties - has been of great scientific and public concern for many years. In this volume experts discuss in depth all relevant issues of airborne particulate matter, including the characterisation of aerosols by modern physical and chemical methods

This study presents the results of a yearlong PM10 measurement campaign, conducted at four sampling sites, within the Greater Athens Area, between June 2001 and May 2002. Daily average PM10 concentrations were determined using reference samplers installed in two urban locations (Maroussi and Aristotelous), a mixed urban-industrial location (Elefsina) and a background location (Thrakomacedones). The 24-h and annual PM10 average concentrations were calculated and compared to the corresponding air quality standards, promulgated by the European Union, revealing severe exceedances of the limit values. The mean concentrations for the sampling periods were 73.8, 83.2, 32.9 and 54.9 mug/m(3) for Maroussi (MAR), Aristotelous (ARI), Thrakomacedones (THR) and Elefsina (ELE), respectively. The spatial variation of PM10, was investigated resulting at a coefficient of variation of 0.36 within the study area and correlation coefficients ranging from 0.57 to 0.84. In addition, strong associations between PM10 and other primary gaseous pollutants were found. Regression analysis of PM10 against NOx (used as an indicator for road traffic emissions) revealed significant vehicular contributions to the measured PM10 concentrations. Higher PM10 levels were recorded during prevailing winds of the S-SW sectors, while lower levels were observed during strong northerly flows. The overall results allowed a first assessment of the severity of PM10 air pollution in the Athens basin, and of the potential sources responsible for it. The control of traffic-related particle emissions appears to be a principal objective, for the confrontation of the PM10 pollution problem affecting the area.

This study presents results from a yearlong particulate matter measurement campaign, conducted across the Greater Athens Area, at four locations, between 1st June 2001 and 31st May 2002. The collected PM10 24-h samples were analyzed for nine toxic metals and metalloids (Pb, As, Cd, Ni, Cr, Mn, V, CLI, Hg). Concerning the five elements regulated by the European Union, annual average concentrations of Ph were found below the limit values at all sites, Cd and Ni concentrations were lower than the prospective assessment thresholds at all sites, concentrations of As exceeded the assessment threshold at two sites, while concentrations of Hg were found below detection limits in all samples. Concentration levels of Mn and V were in compliance with the values proposed by the World Health Organization. The seasonal and spatial variability of metal concentrations was examined and site-specific correlation analysis was conducted for the identification of metals with similar origin. The association between trace metals and NO, concentrations was explored to account for the impact of automotive sources, at two traffic-impacted sites. Cu was the metal most closely linked with the road transport sector. The relation of concentration levels with the prevalence of winds from different sectors was studied in an effort to investigate the transport of metal particles from various zones of the city. Finally, factor analysis was carried out to extract the main components responsible for the variance of the dataset and to attribute them to specific source categories, with vehicle-related sources being important in all cases. (c) 2005 Elsevier Ltd. All rights reserved.