Spatial trends, health risk assessment and ozone formation potential linked to BTEX

Abstract

The current study set out to examine BTEX species comprehensively in order to assess their spatiotemporal distribution, carcinogenic and non-carcinogenic health risk assessment, and ozone formation potential (OFP), source identification, and sensitivity and uncertainty analysis in the capital city of Qom, Iran. Data were gathered from 16 sampling stations in the winter and spring seasons. The average BTEX levels $(\mathrm{\mu }\mathrm{g}/{\mathrm{m}}^3)$ of both sampling periods were 22.49 $\left(\pm \mathrm{}32.05\right)$ for toluene, 15.2 $\left(\pm \mathrm{}19.84\right)$ for benzene, 12.38 $\left(\pm \mathrm{}15.56\right)$ for xylene, and 5.69 $\left(\pm \mathrm{}9.49\right)$ for ethylbenzene. Higher concentrations were observed in the city center and in the proximity of a power plant. Pollution source identification was carried out using principal component analysis (PCA). PCA and the T/B ratio both indicated that industrial sources are the primary pollution source in the spring, while, in the winter, BTEX levels were driven by traffic sources. The highest OFP was determined to be from xylene, followed by toluene, ethylbenzene, and benzene. Among the BTEX species, benzene had the highest cancer $\left(5.9\times {10}^{-5}\right)$ and non-cancer risk $\left(2.5\times {10}^{-1}\right),$ above and under the United States Environmental Protection Agency’s standard, respectively. Pollutant concentration was the most sensitive parameter followed by body weight, inhalation rate, and exposure frequency.

Keywords:

• spatiotemporal analysis
• BTEX
• health risk assessment
• ozone formation potential
• uncertainty analysis

Acknowledgments

The authors would like to appreciate the Research Center for Environmental Pollutants of the Qom University of Medical Science (grant number: 97921) for providing financial support for this research. They also wish to express their thanks to the lab personnel who dedicated their valuable time for the fulfillment of the experimental parts of this research. They also wish to express their thanks to the lab personnel who dedicated their valuable time for the fulfillment of the experimental parts of this research.

Competing of interests

The authors have no competing interests to declare.

Additional information

Funding

The authors would like to appreciate the Research Center for Environmental Pollutants of the Qom University of Medical Science (grant number: 97921) for providing financial support for this research.