Contribution of road traffic to ambient fine particle concentrations (PM<SUB align=right>10</SUB>) in Switzerland

A multivariate receptor model was applied to estimate the contribution of road traffic to ambient levels of fine particles (PM<SUB align=right>10) at different locations in Switzerland. At two roadside sites with heavy local traffic, the road traffic was found to account for 46% and 64% of PM<SUB align=right>10. At an urban background site, the estimated average road traffic contribution was 34%, whereas a slightly higher value was obtained at a suburban site (36%). These results are in agreement with the findings of a recent study, where a conceptually different approach (dispersion modelling) was applied.