Assessment of potentially toxic elements (PTEs) in kaolin dust and associated human health risks near mining areas in eastern Iran

Document Type : Research Paper

Authors

1 School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran.

2 Department of Geology, College of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.

10.22059/ijmge.2026.409947.595357

Abstract

Following reports of silicosis outbreaks among refractory industry workers in eastern Iran, this study analyzed the chemical composition and mineralogical characteristics of mining-derived dust in Ghaenat city and its potential environmental impacts. This study was aimed to investigate the potentially toxic elements (PTEs) concentrations in mine dust and evaluate the human health risk assessment and health effects near mining areas. To achieve this goal, a series of instrumental analyses including XRD, XRF, and ICP-OES have been performed on dust particles. For the better risk assessment, the oral bioaccessibility of PTEs using a simple bioaccessibility extraction test (SBET) was also investigated. X-ray diffraction analysis of dust samples shows that quartz, kaolinite, pyrophyllite, and illite are more abundant, indicating the prevalence of silicates in the dust particles. Calculation of geoaccumulation index indicated that the median Igeo values decreased in the following order: As > S > Sr >> Al ≈ Li ≈ La ≈ Nd ≈ Cu ≈ Pb ≈ Fe ≈ Mg ≈ Zn. Bioaccessibility results revealed pronounced inter-element variability, with arsenic showing the highest bioaccessible fraction (up to 73.1%), particularly in samples collected from the mining area. Although all calculated hazard indices were below the accepted safety threshold, arsenic emerged as the primary contributor to potential health risk.

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[1]. Yu, H., & Zahidi, I. (2023). Environmental hazards posed by mine dust, and monitoring method of mine dust pollution using remote sensing technologies: An overview. Science of the Total Environment 864: 161135. http://dx.doi.org/10.1016/
j.scitotenv.2022.161135.
[2]. Mostafa, M., Farhat, H., Abd El-Bakey, S., Zakaria, M., Zekry, H., & Abu Elwafa, R. (2025). Release of potentially toxic elements from an operational phosphate mine (Sebaiya east, Egypt): geochemical characterizations, environmental risks and mining sustainability. Journal of Environmental Earth Sciences 84:445. https://doi.org/10.1007/s12665-025-12448-1.
[3]. Wang, Zh., Zhou, W., Jiskani, I. M., Luo, H., Ao, Zh., Mvula, E. M. (2022). Annual dust pollution characteristics and its prevention and control for environmental protection in surface mines. Science of the Total Environment 825:153949. http://dx.doi.org/10.1016/j.scitotenv.2022.153949.
[4]. Abbasi, S., Hashemi, N., Rahnama, Sh., Najmeddin, A., Yousefi, M. R., Kardel, F. et al. (2025). Regional and climatic variations in atmospheric microplastic deposition: A study throughout Iran. Environmental Technology & Innovation 40: 104577. https://doi.org/10.1016/j.eti.2025.104577.
[5].  Eby, G.N. (2004). Principles of Environmental Geochemistry. Waveland Press.
[6]. Dill, H. G. (2016). Kaolin: Soil, rock and ore From the mineral to the magmatic, sedimentary and metamorphic environments. Earth-Science Reviews 161: 16–129. http://dx.doi.org/10.1016/j.earscirev.2016.07.003.
[7]. Saffiotti, U., Daniel, L. N., Mao, Y., Williams, A. 0., Kaighn, M. E., Ahmed, N., & Knapton, A. D. (1993). Biological studies on the carcinogenic mechanisms of quartz. In Guthrie, G. D., Jr., and Mossman, B. T. (eds.). Health Effects of Mineral Dusts Reviews in Mineralogy, v. 28. Washington, DC: Mineralogical Society of America, pp. 523-544.
[8]. Ishtiaq, M., Jehan, N., Akbar Khan, S., Muhammad, S., Saddique, U., Iftikhar, B., & et al. (2018). Potential harmful elements in coal dust and human health risk assessment near the mining areas in Cherat, Pakistan. https://doi.org/10.1007/s11356-018-1655-5.
[9]. Wu, L., & Song, Z. (2022). Dust pollution characteristics and control measures of open cut coal mines. Scientific Mining Journal 3: 131 – 140. https://doi.org/1030797/madencilik.1149989.
[10]. Sarkheil, H., Shahbaznejad, M., Rayegani, B., Mohtat, Y., Salahjou, T., & Sadeghy Nejad, A. (2025). Lithium extraction assessment from brines in Kerman province: challenges and opportunities for clean energy transition and climate change mitigation. International journal of mining and geo-engineering, 59(3): 191-200.
[11]. Sarkheil, H., Sadeghy Nejad, A. & Rostamian, E. (2025). Climate-smart mining through block matrix analysis: a conceptual modeling approach for sustainable resource governance. International journal of mining and geo-engineering. Articles in Press.
[12]. Muller, G. (1969). Index of geoaccumulation in sediments of the Rhine River. Geojournal, 2, 108-118.
[13]. U.S. Environmental Protection Agency (EPA). (2008). Standard Operating Procedure for an In Vitro Bioaccessibility Assay for Lead in Soil EPA 9200. pp. 1–86.
[14]. Cao, Z., Zhao, L., Zhu, G., Chen, Q., Yan, G., Zhang, X., & et al. (2017). Propositional modification for the USEPA models for human exposure assessment on chemicals in settled dust or soil. Environ Sci Pollut Res 24(24): 20113–20116.
[15]. U.S. Environmental Protection Agency (EPA). (2001). Risk assessment guidance for superfund: volume III -part A, process for conducting probabilistic risk assessment. EPA 540-R-02-002.
[16]. Ferreira-Baptista, L., De Miguel, E. (2005). Geochemistry and risk assessment of street dust in Luanda, Angola: a tropical urban environment. Atmos Environ 39:4501–4512.
[17]. Zhang, J., Deng, H., Wang, D., Chen, Z., & Xu, S. (2013). Toxic heavy metal contamination and risk assessment of street dust in small towns of Shanghai suburban area, China. Environ Sci Pollut Res 20:323–332. https://doi.org/10.1007/s11356-012-0908-y.
[18]. Najmeddin, A., Moore, F., Keshavarzi, B., & Sadegh, Z. (2018). Pollution, source apportionment and health risk of potentially toxic elements (PTEs) and polycyclic aromatic hydrocarbons (PAHs) in urban street dust of Mashhad, the second largest city of Iran. J. Geochem. Explor. 190, 154–169. https://doi.org/10.1016/j.gexplo.2018.03.004.
[19]. Keshavarzi, B., Tazarvi, Z., Rajabzadeh, M. A., & Najmeddin, A. (2015). Chemical speciation, human health risk assessment and pollution level of selected heavy metals in urban street dust of Shiraz, Iran. Atmospheric Environment,119, 1–10. doi:10.1016/j.atmosenv.2015.08.001.
[20]. Salmanzadeh, M., Saeedi, M., Li, L.Y., Nabi-Bidhendi, Gh. (2015). Characterization and metals fractionation of street dust samples from Tehran, Iran. Int. J. Environ. Res. 9(1), 213–224.
[21]. Alloway, B. (2010). Heavy Metals in Soils: Trace Metals and Metalloids in Soils and their Bioavailability, third ed. Springer Publications, p. 614.
[22]. Liu, E., Yan, T., Birch, G., Zhu, Y. (2014). Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China. Sci. Total Environ. 476, 522–531.
[23]. Nematollahi, M.J., Abbasi, S., Mohammadi, Z., Najmeddin, A., Moravej, S., Yousefi, M.R., & et al. (2022). Evaluation of the 13 May 2018 frontal dust storm in Shiraz: Stable isotopes signature, source apportionment, and concentration of potentially toxic elements. Aeolian Research 58: 100820. https://doi.org/10.1016/j.aeolia.2022.100820.
[24]. Wang, X.S., Qin, Y., & Chen, Y.K. (2007). Leaching characteristics of arsenic and heavy metals in urban roadside soils using a simple bioavailability extraction test. Environ. Monit. Assess. 129, 221–226