Concentrations of Benzene, Toluene and Xylene (BTX) in Ambient air of Rohtak city, India

Environmental monitoring of a particular locality is very important because it has become a serious threat to human beings.The levels of benzene, toluene and xylene of Rohtak (one of the districts of Haryana) were monitored by Passive sampling method.  The air samples collected from six different sites using thermal desorption tube were analyzed by Gas Chromatography (GC) with flame ionization detector (FID).  Among all the selected sites, levels of benzene were found maximum at petrol pump as compared to the residential site, traffic intersection and industrial area.  During winter season the BTX level was higher (Benzene: 4.3, 16.5, 12.2, 7.6, 22.3 and 15.6 µg/m3, Toluene: 16.3, 56.2, 30.9, 40.8, 55.5 and 50.2 µg/m3, Xylene: 6.3, 9.6, 8.5, 8.9, 9.2 and 8.4 µg/m3) as compared to summer (Benzene: 4.0, 12.6, 8.5, 8.8, 12.3 and 10.8 µg/m3, Toluene: 38.2, 53.1, 39.8, 42.6, 49.6 and 47.2 µg/m3 xylene: 2.3, 8.4, 6.8, 8.0, 7.5 and 5.4 µg/m3) and monsoon (Benzene: 2.3, 7.2, 5.6, 6.0, 7.0 and 7.4 µg/m3, Toluene: 5.0, 24.0, 14.5, 16.3, 24.8 and 24.6 µg/m3, Xylene: 1.8, 6.6, 4.2, 6.3, 6.6 and 6.4 µg/m3) seasons among all the sites. The levels of toluene were observed three times higher (50.2 µg/m3) than the benzene (15.6 µg/m3). The benzene level at petrol pump, industrial area and traffic intersection were observed higher than the standard values.