Concentrations of monoaromatic hydrocarbons in the air of the underground car park and individual garages attached to residential buildings

Abstract

The paper describes the characteristics of a two-level underground car park and three individual garages attached to residential buildings, differing by the resident utilization habits, located in North Poland (Tri-City agglomeration area). The strategy of collecting the analyte samples from air in mentioned enclosed areas, concerning the determination of benzene, toluene, ethylbenzene, o-xylene and p,m-xylenes (BTEX) concentrations was performed using passive sampling technique – Radiello® diffusive passive samplers with graphitised charcoal cartridge as a sorption medium. The stage of liberation and final determination of collected analytes was conducted with the use of thermal desorption-gas chromatography-flame ionisation detector (TD-GC-FID) system. As a result of the performed measurements in two-level underground car park, it was observed that the time-weighted average concentrations of BTEX in air were as follows: Level-1 – benzene – 5.2±1.1μg/m3, toluene – 12.3±2.4μg/m3, ethylbenzene 2.85±0.80μg/m3, o-xylene – 4.6±1.4μg/m3, p, m-xylenes – 8.8±2,4μg/m3; Level-2 – benzene - 5.2±1.1μg/m3, toluene – 12.9±3.6μg/m3, ethylbenzene – 2.73±0.79μg/m3, o-xylene – 4.2±1.1μg/m3, p, m-xylenes – 8.5±2.3μg/m3. As for residential garages, the time-weighted average concentrations of BTEX in air were in the following ranges: from 5.9 to 53μg/m3 (benzene), from 7.1 to 195μg/m3 (toluene), from 3.0 to 39μg/m3 (ethylbenzene), from 5.6 to 44μg/m3 (o-xylene) and from 6.3 to 99μg/m3 (p,m-xylenes). Also, BTEX concentration ratios such as: tol/benz ratio and (m, p)-xyl/et.benz coefficient, were calculated based on the obtained results to assess the “freshness” of air mass and the influence exerted by vehicle movement on the concentration of BTEX in air in studied enclosed areas.