Source apportionment and pollution of BTEX in indoor and outdoor air of Guangzhou hospitals

Five BTEX compounds (including benzene, toluene, ethylbenzene, m, p-xylenes and o-xylenes) in indoor and outdoor air samples collected from four hospitals of Guangzhou were determined by the preconcentrator-GC/MS system. The average of sum concentrations of five BTEX varied from 10.61 to 253.35 μg/m3. Toluene was the most abundant BTEX. All concentrations of benzene, toluene and xylenes met the Indoor air quality standard of China, and were lower than those observed in the hospitals of other countries. The indoor concentrations of BTEX were a little higher than their outdoor counterparts. The ratios of indoor/outdoor (I/O) BTEX concentrations were >1.0 in most sampling sites. The strong correlations among the four BTEX (except benzene) indicated that they might have common sources. Furthermore, the results of principal component analysis (PCA) showed that BTEX in indoor air of Guangzhou hospitals might derive from decoration materials and vehicular exhaust.