Assessment of Pollution in the Central Soils of Khuzestan Province with Potentially Toxic Elements (PTEs) and their Origins

Document Type : Research Article

Authors

• N. Sahraei ¹
• A. Landi ¹
• S. Hojati ¹
• Edoardo Pasolli ²

¹ Department of Soil Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Khuzestan, Iran

² Department of Agricultural Sciences,University of Naples Federico II, Naples, Italy

https://doi.org/10.22067/jsw.2023.81161.1254

Abstract

Introduction
In recent years, soil contamination with potentially toxic elements (PTEs) has become a major problem in most parts of the world. PTEs are naturally generated from the pedogenesis in the soil and are formed mainly by rock weathering. Nevertheless, the natural content of metals, i.e., Cr, Zn, Ni, Pb, Cd, used to be low in the soil, but due to anthropogenic activities such as industrial emissions, atmospheric transportation, sewage irrigation, and application of pesticides and fertilizers, there is an increase in the content of PTEs. PTEs in soil are one of the most important environmental pollutants due to their toxicity, durability, easy absorption by plants and long half-life. Therefore, the assessment of soil health is very important for the sustainable development of agriculture and the rehabilitation of soils contaminated with PTEs. The present study was conducted to quantify PTEs pollution for soil environmental assessment using a flexible approach based on multivariate analysis and using pollution indicators in a part of the central lands of Khuzestan province.
 
Materials and Methods
For this purpose, in February 2021, 200 surface soil samples (0-10 cm) were taken using stratified random sampling. The collected soil samples were cleaned by removing plant materials and other pebbles, and air dried, powdered, and sieved by using a 2 mm sieve size. The interest in soil's physical and chemical properties i.e., pH was determined with a digital pH meter. Soil textural particles were measured by the hydrometer method, soil organic carbon (SOC) content was estimated by following Walkley and Black method, bulk density (BD) was measured by the Clod method, and total metal content was determined using the aqua-regia solution digestion method and analyzed using Inductively Coupled Plasma-Optical Emission spectrometry (ICP-OEC). The level of Pb, Ni, Zn, Cr pollution was estimated based on environmental indicators including contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), pollution index of individual metals (PI), and modified pollution index of individual metals (MPI). Multivariate statistical methods including correlation analysis, cluster analysis (CA), and principal component analysis (PCA) were used to find the source of metals in the soil. All statistical methods were performed using SPSS (26 version) software.
 
Results and Discussion
Measurement of soil pH showed that the soil of the studied area tends to alkalinity. Also, the soil texture in this area is loam. The results showed that the SOC in these soil samples is 0.71%, and the range of EC (between 0.18 and 60.5 dS/m) indicates the distribution of saline and non-saline soils in the studied area. The total average concentration of Zn, Ni, Cr, and Pb were 60.26, 50.96, 50.38, and 12.67 mg/kg, respectively. The order of average for heavy metals was Zn> Ni> Cr> Pb. The highest amount of standard deviation and concentration changes were observed in Zn and Pb elements. These two elements also showed a high degree of variation coefficient in the studied area, which can indicate the high impact of human activities on the content of these elements. The results obtained from the application of multivariate statistics showed that there is a positive correlation between the elements such as Zn, Ni, and Pb in the study area, indicating that these metals probably have the same source. Whereas the absence of correlation of Cr with these elements indicates a separate source for this element compared to Pb, Zn, and Ni. There was also a strong relationship among these elements based on the PCA and CA classification. Based on the multivariate statistical analysis the source of pollution for the metals studied was mainly from both anthropogenic and geogenic activities. The results showed that the soil samples taken from the study area are in the low pollution category based on the individual element indices of CF and Igeo, but in the moderate pollution class based on the EF index. In addition, the evaluation based on the cumulative and multi-element indices of PI and MPI showed that 100% of samples have high pollution.
 
Conclusion
The present study concludes that the average values of Zn, Ni, Cr, and Pb were found to be below the guidelines set by the IEPA (Iran Environmental Protection Agency) as well as the Earth's crust values. The results indicate existing relationships among the studied variables, revealing that the heavy metals Zn, Ni, and Zn share the same source in the study area. Additionally, it was observed that the source of Cr is primarily geogenic in nature. These findings highlight the significance of utilizing multivariate statistical methods and pollution indicators in tandem, as they prove to be valuable tools for evaluating and quantitatively determining the potential pollution risk.
 

Keywords

• Cr
• Enrichment factor
• Multivariate statistics
• Ni
• Pb
• Zn

20.1001.1.20084757.1402.37.3.8.1

Main Subjects

• Soil science

References

1. Abyat, A., Azhdari, A., Jodaki, M., and Darvishi Khatoni, J. (2017). Study and separation of Quaternary sedimentary environments in Khuzestan plain. Advanced Applied Geology, 7(3): 49-64. (In Persian with English abstract). https://doi.org/22055/aag.2017.21931.1702.
2. Al-Wabel, M.I., Sallam, A.E.A.S., Usman, A.R., Ahmad, M., El-Naggar, A.H., El-Saeid, M.H., and Al-Romian, F.A. (2017). Trace metal levels, sources, and ecological risk assessment in a densely agricultural area from Saudi Arabia. Environmental Monitoring and Assessment, 189(6): 252. https://doi.org/10.1007/s10661-017-5919-1.
3. Adimalla, N. (2020). Heavy metals pollution assessment and its associated human health risk evaluation of urban soils from Indian cities: a review. Environmental Geochemistry and Health, 42(1): 173–190.
4. Adimalla, N., and Wang, H. (2018). Distribution, contamination, and health risk assessment of heavy metals in surface soils from northern Telangana, India. Arabian Journal of Geosciences, 11: 684. https://doi.org/10.1007/ s12517-018-4028-y.
5. Ahmed, F., Fakhruddin, A.N.M., Imam, M.D., Khan, N., Khan, T.A., Rahman, M.M., and Abdullah, A.T.M. (2016). Spatial distribution and source identification of heavy metal pollution in roadside surface soil: a study of Dhaka Aricha highway, Bangladesh. Ecological Processes 5:2.
6. Amuno, S.A. (2013). Potential ecological risk of heavy metal distribution in cemetery soils. Water, Air and Soil Pollution 224 (2):1435.
7. Arenas-Lago, D., Vega, F.A., Silva, L.F.O., and Andrade, M.L. (2014). Copper distribution in surface and subsurface soil Environmental Science and Pollution Research, 21:10997–11008.
8. Baltas, H., Sirin, M., Gokbayrak, E., and Ozcelik, A.E. (2020). A case study on pollution and a human health risk assessment of heavy metals in agricultural soils around Sinop province, Turkey. Chemosphere, 241: 125015. https://doi.org/10.1016/j.chemosphere.2019.125015.
9. Barakat, A., Ennaji, W., Krimissa, S., and Bouzaid, M. (2019). Heavy metal contamination and ecological-health risk evaluation in peri-urban wastewater-irrigated soils of BeniMellal city (Morocco). International Journal of Environmental Health Research. https://doi.org/10.1080/09603123.2019.1595540.
10. Bhuiyan, M.A.H., Parvez, L., Islam, M., Dampare, S.B., and Suzuki, S. (2010). Heavy metal pollution of coal mine-affected agricultural soils in the northern part of Bangladesh. Journal of Hazardous Materials, 173:384–392.
11. Black, G., and Hartge, K. (1986). Bulk density. Methods of Soil Analysis. Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling.
12. Brady, J.P., Ayoko, G.A., Martens, W.N., and Goonetilleke, A. (2015). Development of a hybrid pollution index for heavy metals in marine and estuarine sediments. Environmental Monitoring and Assessment, 187(5): 306.
13. Cerqueira, B., Vega, F.A., Silva, L.F., and Andrade, L. (2012). Effects of vegetation on chemical and mineralogical characteristics of soils developed on a decantation bank from a copper mine. Science of the Total Environment, 421:220–229.
14. Damian, F., Damian, G., Lăcătuşu, R., Macovei, G., Iepure, G., Năprădean, I., Chira, R., Kollar, L., Raţă, L., and Zaharia, D.C. (2008). Soils from the Baia Mare zone and the heavy metals pollution. Carpathian Journal of Earth and Environmental Sciences, 3(1): 85-98.
15. Dragović, S., Mihailović, N.‚ and Gajić‚ B. (2008). Heavy metals in soils: distribution, relationship withsoil characteristics and radionuclides and multivariate assessment of contamination sources. Chemosphere, 72 (3): 491– 495.
16. Gee, G.W. and Bauder, J.W. (1986). Particle size analysis, In A. Klute (Ed), Methods of Soil Analysis. Part I, American Statistical Association and Soil Science Society of America (ASA) Monograph.
17. Hakanson, L. (1980). An ecological risk index for aquatic pollution control. A sedimentological approach. Water Research, 14(8):975– 1001. https://org/10.1016/0043-1354(80)90143-8.
18. Hojati, S. (2017). Pollution assessment and source apportionment of arsenic, lead and copper in selected soils of Khuzestan Province, southwestern Iran. Arabian Journal of Geosciences, 10:528. https://org/10.1007/s12517-017-3316-2.
19. Hormozi Nejad, F., Rastmanesh, F., and Zarasvandi, A. (2017). Contamination assessment of heavy metals in the soils around Khouzestan Steel Company (KSC) (Ni, Mn, Pb, Fe, Zn, Cr). Journal of Economic Geology, 8(2):429-415. (In Persian with English abstract).
20. Huang, Y., Chen, Q., Deng, M., Japenga, J., Li, T., Yang, X., and He, Z. (2018). Heavy metal pollution and health risk assessment of agricultural soils in a typical peri-urban area in Southeast China. Journal of Environmental Management, 207:159–168.
21. Ielpo, P., Leardi, R., Pappagallo, G., and Uricchio, V.F. (2017). Tools based on multivariate statistical analysis for classification of soil and groundwater in Apulian agricultural sites. Environmental Science and Pollution Research, 24(16):13967–13978.
22. Jiang, X., Lu, W., Zhao, H., Yang, Q., and Yang, Z. (2014). Potential ecological risk assessment and prediction of soil heavy-metal pollution around coal gangue dump. Natural Hazards and Earth System Sciences, 14(6):1599-610.
23. Keshavarzi, A., and Kumar, V. (2019).Ecological risk assessment and source apportionment of heavy metal contamination in agricultural soils of northeastern Iran. International Journal of Environmental Health Research, 29(5): 1–17. https://doi.org/10.1080/09603123.2018.1555638.
24. Kumar, V., Sharma, A., and Thukral, A.K. (2016). Assessment of soil enzyme activities based on soil samples from the Beas river bed, India using multivariate techniques. Malaysian Journal of Soil Science, 20:135–145.
25. Kumar, V., Sharma, A., Bhardwaj, R. M., and Thukral, A. K. (2018). Temporal distribution, source apportionment, and pollution assessment of metals in the sediments of Beas River, India. Human and Ecological Risk Assessment: An International Journal, 24(8): 2162–2181.
26. Loska, K., Wiechula, D., and Korus, I. (2004). Metal contamination of farming soils affected by industry. Environment International, 30 (2):159–165.
27. Maas, S., Schei, R.‚ Benslama, M.‚ Crini, N.‚ Lucot, E.‚ Brahmia, Z.‚ and Giraudoux‚ P. (2010). Spatial distribution of heavy metal concentrations in urban, suburban and agricultural soils in a Mediterranean city of Algeria. Environmental Pollution, 158: 2294– 2301.
28. Mirsal, I.A. (2008). Soil pollution: origin, monitoring and remediation. Berlin Heidelberg: Springer-Verlag. https://doi.org/10.1007/978-3-540-70777-6.
29. Nemerow, N.L. (1991). Stream, lake, estuary, and ocean pollution. New York (USA): John Wiley and Sons, Inc.
30. Qingjie, G., Jun, D., Yunchuan, X., Qingfei, W., and Liqiang, Y. (2008). Calculating pollution indices by heavy metals in ecological geochemistry assessment and a case study in parks of Beijing. Journal of China University of Geosciences, 19(3):230–241.
31. Rashed, M.N. (2010). Monitoring of contaminated toxic and heavy metals, from mine tailings through age accumulation, in soil and some wild plants at Southeast Egypt. Journal of Hazardous Materials, 178(1–3):739–746.
32. Rezapour, S., Golmohammad, H., and Ramezanpour, H. (2014). Impact of parent rock and topography aspect on the distribution of soil trace metals in natural ecosystems. International Journal of Environmental Science and Technology, 11(7): 2075–2086.
33. Rodriguez, R., and Redman, R. (2008). More than 400 million years of evolution and some plants still can’t make it on their own: plant stress tolerance via fungal symbiosis. Journal of Experimental Botany. 59: 1109–1114. https://doi.org/10.1093/jxb/erm342.
34. Salminen, R., Batista, M.‚ Bidovec, M.‚ Demetriades, A.‚ DeVivo, B.‚ DeVos, W.‚ Duris, M.‚ and Tarvainen‚ (2005). FOREGS Geochemical Atlas of Europe, Part 1 : Background Information, Geochemical Atlas of Europe Part 2 Interpretation of Geochemical Maps, Additional Tables, EuroGeoSurveys.
35. Sakram, G., Machender, G., Dhakate, R., Saxena, P. R., and Prasad, M. D. (2015). Assessment of trace elements in soils around Zaheerabad Town, Medak District, Andhra Pradesh, India. Environmental Earth Sciences, 73: 4511–4524.
36. Siyahati Ardakani, G., Mirsanjari, M., Azimzadeh, H., and Solgi, E. (2019). Ecological Risk Assessment of Heavy Metals in TopsoilAround Major Industries of Ardakan City. Toloo-e-Behdasht Journal, 17(6): 95-100. (In Persian with English abstract).
37. Song, T., Su, X., He, J., Liang, Y., and Zhou, T. (2018). Source apportionment and health risk assessment of heavy metals in agricultural soils in Xinglonggang, Northeastern China. Human and Ecological Risk Assessment, 24(2): 509–521.
38. Walkley, A. and Black, I.A. 1934. An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil science, 37(1): 29-38.
39. Stafilov, T., Sajn, R., Boev, B., Cvetkovic, J., Mukaetov, D., Andreevski, M., and Lepitkova, S. (2010). Distribution of some elements in surface soil over the Kavadarci region, Republic of Macedonia. Environmental Earth Sciences, 61(7):1515–1530.
40. Suresh, G., Sutharsan, P., Ramasamy, V., and Venkatachalapathy, R. (2012). Assessment of spatial distribution and potential ecological risk of the heavy metals in relation to granulometric contents of Veeranam lake sediments, India. Ecotoxicology and Environmental Safety, 84: 117–124. https://doi. org/10.1016/j.ecoenv.2012.06.027.
41. Tian, K., Huang, B., Xing, Z., and Hu, W. (2017). Geochemical baseline establishment and ecological risk evaluation of heavy metals in greenhouse soils from Dongtai, China. Ecological Indicators, 72: 510–520.
42. Tholkappian, M., Ravisankar, R., Chandrasekaran, A., Jebakumar, J.P.P., Kanagasabapathy, K.V., Prasad, M.V.R., and Satapathy, K.K. (2018). Assessing heavy metal toxicity in sediments of Chennai Coast of Tamil Nadu using Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) with statistical approach. Toxicology Reports, 5:173–182.
43. Thomas, G.W. (1996). Soil pH and soil acidity. Methods of soil analysis. Madison (WI): American Society of Agronomy and Soil Science Society of America.
44. Turekian, K., and Wedepohl, K.H. )1961(. Distribution of the elements in some major units of the earth's crust. Geological Society of America Bulletin 72: 175-192/
45. Wang, Y., Hu, J., Xiong, K., Huang, X., and Duan, S. (2012). Distribution of heavy metals in core sediments from Baihua Lake. Procedia Environmental Sciences, 16:51–58.
46. Wilding, L. P. (1985). Spatial variability: its documentation, accomodation and implication to soil surveys. In Soil spatial variability, Las Vegas NV, 30 November-1 December 1984.
47. Yalcin, M.G., Battaloglu, R., and Ilhan, S. (2007). Heavy metal sources in Sultan Marsh and its neighborhood, Kayseri, Turkey. Environmental Geology, 53(2): 399-415.
48. Ye, C., Li, S., Zhang, Y., and Zhang, Q. (2011). Assessing soil heavy metal pollution in the water-level-fluctuation zone of the Three Gorges Reservoir, China. Journal of Hazardous Materials, 191(3): 366-372.
49. Yinxian, S., Junfeng, J., Zhongfang, Y., Xuyin, Y., Changping, M., Ray, F., and Ayoko, G. (2011). Geochemical behavior assessment and apportionment of heavy metal contaminants in the bottom sediments of lower reach of Changjiang River, Catena, 85:73 – 81
50. Yongming, H., Peixuan, D.‚ Junji, C.‚ and Posmentier, E.S. (2006). Multivariate analysis of heavy metal contamination in urban dusts of Xi’an, Central China. Science of the Total Environment‚ 355 (1– 3): 176– 186
51. Zhang, C., Yang, Y., Li, W., Zhang, C., Zhang, R., and Mei, Y. (2015). Spatial distribution and ecological risk assessment of trace metals in urban soils in Wuhan, central China. Environmental Monitoring and Assessment, 187(9):556.