Influence of vehicle traffic reduction in a town centre on BTX pollution
Résumé
Every 22 September, several French towns impose a strong reduction of traffic in their centre. In 1998, we realised a three days BTX sampling campaign in Nancy, in order to quantify the impact of the traffic restrictions on air quality. Sampling sites were chosen close to the busiest traffic routes. Sampling was performed with passive tubes, on ten hours each day. Measurements show clearly that the traffic flow reduction led to a decrease in BTX roadside concentrations by between 30 to 80%. BTX measurements correlate well with CO levels monitored at one of the sampling sites, and with the volume of traffic in circulation each day, which clearly indicates that traffic is the main source of atmospheric pollution at these sites. With limited traffic, benzene levels measured at roadside nearly fulfil the proposed European limit value and the French target value for air quality