33 The disparity between personal and ambient air sampling of BTEX in small roadside garages

Background The chemical exposure assessment for workers is essential in terms of chemical hazard prevention. The air sampling and quantitation of chemicals in workplaces is a direct and sound technique to assess the workers’ exposure. However, a reliable workplace measurement for exposure assessment does depend on a suitable sampling strategy that may be determined by the exposure (or work) characteristic. This study aimed to compare the personal and ambient air sampling for micro-workshop (i.e. small garages) in order to evaluate the BTEX exposure of motorbike mechanics. Method A total of ten motorbike garages was recruited and investigated. The personal and ambient air sampling were conducted five time for each garage in summer and winter season, respectively. Personal and Ambient samples were collected by 3 M passive samplers and charcoal tubes, respectively. After solvent extraction, BTEX were quantified by a GC-MS. Results The ambient levels of BTEX were 45.7 ± 47.8, 422.9 ± 744.3, 78.0 ± 166.6, 206.4 ± 400.7 ug/m3, respectively. For personal samples, they were 154.7 ± 43.2, 300.4 ± 187.8, 162.2 ± 60.66, 349.6 ± 73.26 ug/m3, respectively. Obviously, there was significant difference between personal and ambient air samples. Notably, the levels of personal exposure were much higher than those of ambient air samples. Conclusion This study indicated that the ambient air sampling cannot well estimate the occupational exposure for vehicle mechanics who worked in a small workplace. Personal sampling should be utilized to assess their occupational exposure to BTEX. In addition, the short term exposure during each tasks should be further evaluated; thus the potential health risk can be fairly estimated and managed.