Ambient volatile organic compounds in the atmosphere of industrial central India

Volatile organic compounds (VOCs) are an important group of compounds because of their role in atmospheric chemistry and the risk they pose to human health and ecosystem. Therefore, the interest in determining VOCs in the atmosphere has increased over the last few decades to understand their emission, distribution, and sources. Considering the expanding urbanization and increasing use of fuels, very limited data of VOCs in India is available. This paper describes the chemical analysis of 12 light VOCs in 144 ambient air samples collected from three different sites near Raipur, India during a period of April, 2006-March, 2007 in order to understand their temporal and spatial distributions. This data has provided some important insights into the VOC profile, for the first time, of an industrial area in India. The annual average concentrations of all 12 VOCs in our study ranged from 43.2 to 160.4 μg m^?3 (mean: 95.6?±?31.0). The annual average concentration of individual VOCs in Raipur region ranged from 3.4 μg m^?3 for xylenes to 18.3 μg m^?3 for n-butane. n-Butane, i-butane, and propane were the three most abundant pollutants among all of the VOCs measured. The observed concentrations of these compounds in Raipur region were comparable to other Asian cities with some exceptions. The levels of total VOCs showed seasonal variations with a statistically significant winter maximum and lower values during summer and monsoon ranging from 55.9?±?9.9 μg/m³ in August to 144.5?±?15.5 μg/m³ in January. Sources of these VOCs have been described using species ratios and correlation studies.