Temporal variability of benzene concentration in the ambient air of Delhi: A comparative assessment of pre- and post-CNG periods

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• 作者：P.S. Khillare ; Raza Rafiqul Hoque ; Vijay Shridhar ; Tripti Agarwal ; S. Balach ; ran
• 关键词：Benzene ; Delhi ; Seasonal variation ; Spatial variation ; Vehicular exhaust
• 刊名：Journal of Hazardous Materials
• 出版年：2008
• 出版时间：15 June 2008
• 年：2008
• 卷：154
• 期：1-3
• 页码：1013-1018
• 全文大小：303 K

文摘

CNG (compressed natural gas) was fully implemented in public transport system in Delhi in December 2002. The study assesses the benzene concentration trends at two busy traffic intersections and a background site in Delhi, India. Monitoring was done for two different time periods viz; in the year 2001–2002 (pre-CNG) and two winter months (January and February) of the year 2007 (post-CNG) to assess the impact of various policy measures adopted by the government of Delhi to improve the air quality in the city. Annual average benzene concentration for the pre-CNG period was found to be 86.47 ± 53.24 μg m⁻³. Average benzene concentrations for the winter months (January–February) of pre- and post-CNG periods were 116.32 ± 51.65 μg m⁻³ and 187.49 ± 22.50 μg m⁻³, respectively. Enhanced values could be solely attributed to the increase in the vehicular population from 3.5 million in the year 2001–2002 to 5.1 millions in the year 2007.