Ambient BTEX and MTBE in the neighborhoods of different industrial parks in Southern Taiwan

This study assessed the concentrations of five volatile organic compounds (VOCs), including BTEX (the acronym for benzene, toluene, ethylbenzene, and xylene) and methyl tertiary-butyl ether (MTBE), in six different industrial park neighborhoods in southern Taiwan, including the Nei-Pu, Ping-Tung, Ping-Nan, Ren-Wu, Lin-Yuan and Nan-Zi industrial parks. The concentrations of MTBE and BTEX ranged from undetectable to 145.6 μg/m3. Average MTBE–BTEX ratios of Nei-Pu, Ping-Tung, Ping-Nan, Ren-Wu, Lin-Yuan and Nan-Zi were (13.4:3.6:4.7:1.0:7.4), (2.9:1.0:1.7:1.3:2.9), (3.0:1.0:2.7:1.0:2.7), (5.2:1.0:8.6:1.7:4.9), (3.1:3.1:2.8:1.0:3.3) and (4.3:1.2:3.6:1.0:3.8), respectively. Moreover, average T/B ratios in Nei-Pu, Ping-Tung, Ping-Nan, Ren-Wu, Lin-Yuan and Nan-Zi were 1.3, 1.7, 2.6, 8.6, 0.9 and 2.9, respectively. High T/B ratio (8.6) in the neighborhood of the Ren-Wu industrial park suggested that the emission of large additional sources of toluene from this industrial park, or the existence of major differences in the auxiliary fuels used. Average X/E ratios in Nei-Pu, Ping-Tung, Ping-Nan, Ren-Wu, Lin-Yuan and Nan-Zi were 7.4, 2.2, 2.7, 2.9, 3.3 and 3.8, respectively. The lower X/E ratio (2.2) in the Ping-Tung neighborhood compared to elsewhere indicates an aged air parcel. Furthermore, principal component analysis also confirmed that the dominant influences in the six different industrial park neighborhoods were related to the emissions of MTBE, benzene and toluene.