Characterization of BTEX sources in a medium-size city by concentration statistical analysis and GIS technique

Abstract

The concentrations of benzene, toluene, ethylbenzene and the isomeric xylenes (BTEX) were determined in the atmosphere of S. Maria Capua Vetere city, in sixteen sites, ten times per site, during 2006. This city is of medium size, with about 32,000 inhabitants and is located in Southern Italy. Passive adsorption samplers, followed by GC/MS analyses, were used for BTEX determinations. The 24-hour average BTEX concentrations showed a marked variability from site to site. In some streets the pollutant concentrations were above the limit values required by the European Union. These streets were characterised by relatively intense traffic, but are rather narrow and have high buildings on either side. In the entire city the main pollutant source was road traffic. Moreover, analyses of the correlation coefficients among the BTEX concentrations and GIS maps highlighted the contribution of stationary sources to toluene air concentration. Their contribution has been quantified.