The benzo[a]pyrene temporal trend was investigated in 11 towns where at least five annual means were available. The overall number of stations was 22, of which 12 were traffic-oriented, 6 background and 4 industrial. The trend was generally declining at traffic-oriented sites and roughly stable at background sites. The annual means in 2004 still exceeded the forthcoming European target value of 1 ng/m 3 in two towns (up to 1.9 ng/m 3 ). The background means (up to 1.4 ng/m 3 in 2004) accounted for approximately 40–90% of those at the traffic-oriented sites in the same town. The presence of a coke plant was incompatible with the attainment of the target value, while the adoption of technical measures on a carbon electrode plant was successful in attaining concentrations lower than the target value. In heavy traffic areas in Italy, the attainment of the target value hardly appears feasible under the current conditions of traffic congestion.
The collaboration of the following persons in the determination of BaP concentrations is acknowledged: L. Giorgini and I. Pellegrini (ARPA Friuli Venezia Giulia), and F. Monfredini (Istituto Superiore di Sanità). An acknowledgement is also due to ARPA Liguria and Genoa Province-Area Environment for providing data and information on measurements in Genoa.
Notes
a 16 consecutive days.