PASSIVE SAMPLING OF AROMATIC VOLATILE ORGANIC-COMPOUNDS (VOC) IN AMBIENT AIR IN SWITZERLAND

Concentrations of benzene, toluene and m-xylene (BTX) were measured at urban, suburban, rural and alpine sites in Switzerland by means of pa ssive sampling. Sampling time was two weeks and the sampling period wa s six months in succession. Concentrations ranged between 0.8 and 6 pg m(-3) for benzene, between 2.9 and 14 mu g m(-3) for toluene and betw een 0.9 and 7.4 mu g m(3) for m-xylene. The ratios between benzene tol uene and m-xylene concentrations were on average 1:3:1.1. Passive samp lers have been found to be a useful tool for the synchronical determin ation of VOC in different regions. Comparison with continuous monitors showed some systematic bias, however. Correlation of VOC with other a ir pollutants were strong with CO and NO.