Kumar, Amit and Singh, Deepak and Kumar, Krishan and Singh, Braj Bihari and Jain, Vinod Kumar (2018) Distribution of VOCs in urban and rural atmospheres of subtropical India: Temporal variation, source attribution, ratios, OFP and risk assessment. Science of the Total Environment, 613. pp. 492-501. ISSN 0048-9697

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Abstract

This paper reports the first study which comprises the seasonal, diurnal variability, source characterization, ozone forming potential and risk assessment of volatile organic compounds (VOCs) at three sites (two urban and one rural) in the National Capital Territory of Delhi, India. The study was performed during three seasons of the year 2013-14 and two different categories of VOCs (aromatics and halogenated) have been selected. The study used the sampling and analytical procedures of NIOSH methods. Results showed that the mean concentration of sum of VOCs (Sigma VOC) is significantly higher at urban sites (110.0 and 137.4 mu g/m(3) for JN and CP, respectively) as compared to the rural site, DP (56.5 mu g/m(3)). The contribution of individual to total VOC concentrations is noticed to be very similar at all the three sites. Most of the VOCs are observed to be significantly higher in winter followed by summer and autumn. Diurnal cycles of aromatic VOCs are highly influenced by the vehicular traffic and photochemical oxidations which showed higher and lower levels during morning/evening and daytime, respectively. Diagnostic ratios of the toluene/benzene (ranged from 0.65 to 13.9) infers the vehicular traffic might be the main contributing source in the urban sites while xylene/benzene ratio (ranged from 0.7 to 2.8) confirms the VOCs are transported to rural site from the nearby urban areas. Correlation and factor analysis suggested the sources are group of different species (traffic emissions, solvent usage and industrial) rather than single gas. The analysis of reactivity in terms of Prop-Equiv concentrations and ozone forming potential indicated that m/p-xylene and toluene are the main VOC contributing to the total ozone formation in urban and rural sites, respectively. Hazard ratios and lifetime cancer risk values exceeded the permissible standards established by USEPA and WHO suggests that the people are at significant risk.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier.
Subjects:	Earth Sciences Geography, Physical
Divisions:	UNSPECIFIED
Depositing User:	Mr. Yogesh Joshi
Date Deposited:	29 Nov 2019 11:00
Last Modified:	29 Nov 2019 11:00
URI:	http://npl.csircentral.net/id/eprint/3884

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