Spatiotemporal variation, ozone formation potential and health risk assessment of ambient air VOCs in an industrialized city in Iran

• Published in: Atmospheric pollution research 2019-03, Vol.10 (2), p.556-563
• Main Authors: Tohid, Leila, Sabeti, Zahra, Sarbakhsh, Parvin, Zoroufchi Benis, Khaled, Shakerkhatibi, Mohammad, Rasoulzadeh, Yahya, Rahimian, Raana, Darvishali, Siamak
• Format: Article
• Language: English
• Subjects: Ambient air; BTXS; Carcinogenic risk; Non-carcinogenic risk; Ozone formation potential
• ISSN: 1309-1042; 1309-1042
• DOI: 10.1016/j.apr.2018.10.007

Volatile organic compounds (VOCs) are common air pollutants that are primarily emitted by motor vehicles and through industrial activity and can have a significant impact on air quality and adversely affect human health. The aim of this study was to characterize benzene, toluene, xylenes and styrene (BTXS) in the ambient air of Tabriz, a city in northwestern Iran, and describe their spatiotemporal variations, ozone formation potential (OFP) and provide a health risk assessment. The measured concentrations of BTXS ranged from 0.46 to 69.32 μg/m3. Diurnal variation showed a significant difference between the morning and evening concentrations, in which the evening values were primarily higher. Spatial analysis showed that the maximum levels of BTXS occurred in the industrial zone. The estimated OFP values ranged from 26 to 418 and 16 to 725 in winter and summer, respectively. In addition, the mean T/B ratio was 1.84, indicating the combustion of fuel in motor vehicles as the main source of VOCs. The hazard ratio of target pollutants was lower than the limits recommended by the USEPA and WHO; however, the estimated lifetime cancer risk for benzene was 7.82 × 10−6, which exceeds the threshold of 1 × 10−6. [Display omitted] •Benzene, toluene, xylenes, and styrene (BTXS) were measured in the urban ambient air of Iran.•Maximum levels of BTXS observed at industrial zone.•The xylenes and toluene were the major contributors of OFP.•Motor vehicles were identified as the main source of VOCs in the study area.•The estimated lifetime cancer risk for benzene was higher than the recommended threshold value.