Investigation of Volatile Mono-Aromatic Hydrocarbons and 1,3-Butadiene in an Urban Metropolis, India.

In urban areas, benzene, toluene, ethyl benzene and xylenes (BTEX) constitute up to 60% of nonmethane VOCs. The present work was conducted to determine the ambient volatile 1, 3-butadiene and mono-aromatic hydrocarbons in an urban metropolis of Nagpur, India. Continuous sampling was carried out at high density traffic junctions, major petrol filling stations along with some residential areas during March to May, 2011. The samples were collected in 10 litre tedlar bags during the peak hours and analyzed within 24 hours by VOC analyzer based on Gas Chromatography-Photo Ionization Detection technique. Appreciably high concentrations of Total BBTEX were observed at petrol filling stations (237.1 μg/m3) and traffic junctions (134.3 μg/m3). The levels of BBTEX observed around a major traffic junction were significant to commuter exposure. In view of the health impacts to commuter, nearby residents and occupational exposure, preventive measures like use of CNG, installation of vapor recovery system at petrol filling stations and use of mask by the workers were needed. The correlation analysis and concentration ratio study indicates the impacts of petrol pumps and vehicular traffic on the urban air quality at the residential sites. The levels of benzene were well within the National Ambient Air Quality Standards at all the residential locations.