TPH and PAHs in an oil-rich metropolis in SW Iran: Implication for source apportionment and human health

Abstract

Several priority environmental mutagens and carcinogenic compounds were investigated in Ahwaz metropolis soil to estimate the extent of contamination and the risk they pose to human health. This included determination of total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs) in 58 and 92 industrial soil samples, respectively, using gas chromatography/mass spectrometry (GC/MS). The results indicate that total TPHs range between 1.2 and 11,000 mg kg⁻¹, with a mean of 999 mg kg⁻¹, while total PAHs concentration vary between 6 and 47,103 µg kg⁻¹, with a mean of 1241 µg kg⁻¹. The mean value of total PAHs in Ahwaz soil is much higher than many industrial soils around the world. The PAHs abundance in the soil samples based on the number of hydrocarbon rings was found in the following order: 4, 3, 2, 5 and 6 ring hydrocarbons. Also, diagnostic ratios indicate that both pyrogenic and petrogenic compounds constitute the sources of these organic pollutants. The incremental lifetime cancer risk resulting from contact with soil PAHs for children and adults is extreme at the industrial sites, however, the risk via inhalation is lower compared with other pathways. The findings of this study provide valuable information about the distribution of harmful organic pollutants in the soil environment.

Keywords:

• Ahwaz metropolis
• industrial activities
• soil pollution
• TPHs and PAHs
• source apportionment

Acknowledgments

The authors wish to express their gratitude to the Khuzestan Environmental Protection Organization for financially supporting this research. The authors also sincerely appreciate the Research Committee and Medical Geology Center of Shiraz University for logistical assistance.

Disclosure statement

The authors declare that they have no competing interests

Availability of data and materials

All data generated or analyzed during this study are included in this published article [and its Supporting Information files].