Isoconcentration maps of BTX in the atmosphere of La Spezia (Italy)

Isoconcentration maps for benzene, toluene, xylenes (BTX) in the air of La Spezia were obtained by temporary networks of passive samplers distributed in the urban and sub urban areas of this Ligurian town. Fifty passive sampl ers were simultaneously exposed for seven days along 27 streets, at about 2 .5 meters height. Mean benzene concentrations found in February and Septemb er (15.8 and 16.7 ug/m3) were comparable to the present air quality Italian guideline (15 ug/m3). The highest benzene concentrations were found along a canyon street (60 ug/m3) and very close to a gasoline pump (31 ug/m3).