Ecological Risk Assessment and Spatial Distribution of Heavy Metals in the Alvand Mountain Ecosystem: A 15-Year Monitoring Study (2008–2022)

Makhfi, Golnar; Ildoromi, Alireza; Mortazavi, Samar

doi:10.34172/jaehr.1413

Ecological Risk Assessment and Spatial Distribution of Heavy Metals in the Alvand Mountain Ecosystem: A 15-Year Monitoring Study (2008–2022)

Document Type : Original Article

Authors

Golnar Makhfi ¹

Alireza Ildoromi ²

Samar Mortazavi ³

¹ Department of Environmental Science, Faculty of Natural Resources and Environments, Malayer University, Malayer, Iran

² Department of Natural Engineering, Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran

³ Faculty of Natural Resources and Environment, Malayer University, Malayer, Iran

10.34172/jaehr.1413

Abstract

Background: Soil contamination by heavy metals represents a critical environmental issue that endangers both ecological balance and human well-being. This study investigates the ecological risks of arsenic (As) and cadmium (Cd) in the Alvand Mountain ecosystem over a 15-year monitoring period (2008–2022), emphasizing their sources, spatial distribution, and associated health risks.
Methods: Systematic random sampling was performed across the Alvand region. Soil samples were analyzed for As and Cd using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Contamination and ecological risk levels were quantified using the Contamination Factor (Cf), Revised Contamination Degree Index (rCd), and Environmental Risk Potential Index (Eir). Geostatistical interpolation methods (Kriging and IDW) were applied to generate spatial distribution maps for 2008 and 2022, with model accuracy validated via Root Mean Square Error (RMSE) and Mean Absolute Error (MAE).
Results: In 2008, As concentrations were highest in the central and northeastern zones, while Cd pollution dominated the western and eastern borders. By 2022, As contamination expanded westward, and Cd became widespread throughout the region. Cd exhibited an Eir value exceeding 447, indicating a very high ecological risk according to the Hakanson classification.
Conclusion: As contamination appears to stem from natural geogenic sources, whereas Cd accumulation is primarily anthropogenic, driven by agricultural activities. Continuous monitoring and stricter fertilizer management are essential to mitigate heavy metal pollution and safeguard the ecological integrity of mountainous ecosystems.

Keywords

Soil pollution

Environmental risk assessment

Ecosystem

Carcinogenic risk

Arsenic

Cadmium

Subjects

Environmental Risk Assessment

1. Hammam AA, Mohamed WS, Sayed SE, Kucher DE, Mohamed ES. Assessment of soil contamination using gis and multi-variate analysis: a case study in El-Minia Governorate, Egypt. Agronomy. 2022;12(5):1197. doi: 10.3390/agronomy12051197.

2. Beigmohammadi F, Solgi E, Soleimani M, Besalatpour AA. Systematic evaluation and meta-analysis of risk, toxicity potential, and carcinogenic and non-carcinogenic risks of potentially toxic elements in Arak city. J Water Soil Sci. 2022;26(3):231-46. doi: 10.47176/jwss.26.3.38973.

3. 3.Zhang X, Sun W, Cen Y, Zhang L, Wang N. Predicting cadmium concentration in soils using laboratory and field reflectance spectroscopy. Sci Total Environ. 2019;650(Pt 1):321-34. doi: 10.1016/j.scitotenv.2018.08.442.

4. Lal R. Restoring soil quality to mitigate soil degradation. Sustainability. 2015;7(5):5875-95. doi: 10.3390/su7055875.

5. Montanarella L, Pennock D, Mckenzie N, Alavipanah SK, Alegre J, Alshankiti A, et al. The Status of the World’s Soil Resources (Technical Summary). Rome, Italy: Food and Agriculture Organization of the United Nations; 2015. p. 98.

6. Fazekašová D, Petrovič F, Fazekaš J, Štofejová L, Baláž I, Tulis F, et al. Soil contamination in the problem areas of agrarian Slovakia. Land. 2021;10(11):1248. doi: 10.3390/land10111248.

7. Mazurek R, Kowalska JB, Gąsiorek M, Zadrożny P, Wieczorek J. Pollution indices as comprehensive tools for evaluation of the accumulation and provenance of potentially toxic elements in soils in Ojców National Park. J Geochem Explor. 2019;201:13-30. doi: 10.1016/j.gexplo.2019.03.001.

8. Hasan AB, Reza A, Siddique MA, Akbor MA, Nahar A, Hasan M, et al. Origin, spatial distribution, sediment contamination, ecological and health risk evaluation of trace metals in sediments of ship breaking area of Bangladesh. J Hazard Mater. 2024;465:133214. doi: 10.1016/j.jhazmat.2023.133214.

9. Olomukoro JO, Enabulele CO. Assessment of heavy metal contamination and sediment characteristics in Ozomu lake, southern Nigeria: implications for environmental health. Kuwait J Sci. 2024;51(2):100192. doi: 10.1016/j.kjs.2024.100192.

10. Zhang H, Li Y, Li R, Wu W, Abdelrahman H, Wang J, et al. Mitigation of the mobilization and accumulation of toxic metal(loid)s in ryegrass using sodium sulfide. Sci Total Environ. 2024;909:168387. doi: 10.1016/j.scitotenv.2023.168387.

11. Khatoon Z, del Carmen Orozco-Mosqueda M, Santoyo G. Microbial contributions to heavy metal phytoremediation in agricultural soils: a review. Microorganisms. 2024;12(10):1945. doi: 10.3390/microorganisms12101945.

12. Chowdhury AI, Shill LC, Raihan MM, Rashid R, Bhuiyan MN, Reza S, et al. Human health risk assessment of heavy metals in vegetables of Bangladesh. Sci Rep. 2024;14(1):15616. doi: 10.1038/s41598-024-65734-6.

13. Panqing Y, Abliz A, Xiaoli S, Aisaiduli H. Human health-risk assessment of heavy metal-contaminated soil based on Monte Carlo simulation. Sci Rep. 2023;13(1):7033. doi: 10.1038/s41598-023-33986-3.

14. Li Y, Ye Z, Yu Y, Li Y, Jiang J, Wang L, et al. A combined method for human health risk area identification of heavy metals in urban environments. J Hazard Mater. 2023;449:131067. doi: 10.1016/j.jhazmat.2023.131067.

15. Sergeev A, Butorova A, Shichkin A, Buevich A, Baglaeva E. Increasing the informativeness of performance assessment of predictive models of heavy metal spatial distributions in the topsoil by permutation approach. Model Earth Syst Environ. 2024;10(3):4387-400. doi: 10.1007/s40808-024-02034-y.

16. Mansour SA, Belal MH, Abou-Arab AA, Gad MF. Monitoring of pesticides and heavy metals in cucumber fruits produced from different farming systems. Chemosphere. 2009;75(5):601-9. doi: 10.1016/j.chemosphere.2009.01.058.

17. Choueiri J. Evaluation of Human Exposure to Environmental Pollutants Through Food [dissertation]. Grenoble: Université Grenoble Alpes; 2024.

18. Lin C, Louie PK, Lau AK, Fung JC, Yuan Z, Tao M, et al. Net effect of air pollution controls on health risk in the Beijing-Tianjin-Hebei region during the 2022 winter Olympics and Paralympics. J Environ Sci (China). 2024;135:560-9. doi: 10.1016/j.jes.2022.10.008.

19. Marín D, Calle N, Arango V, Betancur P, Pérez M, Orozco LY, et al. Knowledge, attitudes and practices about air pollution and its health effects in 6th to 11th-grade students in Colombia: a cross-sectional study. Front Public Health. 2024;12:1390780. doi: 10.3389/fpubh.2024.1390780.

20. Retamal-Salgado J, Hirzel J, Walter I, Matus I. Bioabsorption and bioaccumulation of cadmium in the straw and grain of maize (Zea mays L.) in growing soils contaminated with cadmium in different environment. Int J Environ Res Public Health. 2017;14(11):1399. doi: 10.3390/ijerph14111399.

21. Mitra S, Chakraborty AJ, Tareq AM, Emran TB, Nainu F, Khusro A, et al. Impact of heavy metals on the environment and human health: novel therapeutic insights to counter the toxicity. J King Saud Univ Sci. 2022;34(3):101865. doi: 10.1016/j.jksus.2022.101865.

22. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Arsenic, metals, fibres, and dusts. IARC Monogr Eval Carcinog Risks Hum. 2012;100(PT C):11-465.

23. Mishra R, Datta SP, Golui D, Meena MC, Raza MB, Rahman MM, et al. Mapping arsenic contamination and health risk assessment of arsenic in agricultural soils of eastern India. Water Air Soil Pollut. 2024;235(9):559. doi: 10.1007/s11270-024-07359-z.

24. Yu J, Liu X, Yang B, Li X, Wang P, Yuan B, et al. Major influencing factors identification and probabilistic health risk assessment of soil potentially toxic elements pollution in coal and metal mines across China: a systematic review. Ecotoxicol Environ Saf. 2024;274:116231. doi: 10.1016/j.ecoenv.2024.116231.

25. Amiri H, Daneshvar E, Azadi S, Azadi S. Contamination level and risk assessment of heavy metals in the topsoil around cement factory: a case study. Environ Eng Res. 2022;27(5):210313. doi: 10.4491/eer.2021.313.

26. Jing X, Wang X, Zhou J, Lu Y. Spatiotemporal variations and health risks of arsenic in soils of the Pearl River basin, China. Sci Total Environ. 2024;951:175393. doi: 10.1016/j.scitotenv.2024.175393.

27. Zhang T, Zheng B, Wang M, He J, Xia S. Spatial distribution, occurrence form, availability and ecological risk assessment of arsenic in soils of riparian zones on the Tibetan Plateau. Gondwana Res. 2024;130:131-9. doi: 10.1016/j.gr.2024.01.007.

28. Baaghideh M, Fallah Ghalhari G, Hajimohammadi H, Rezaei H. Investigating the role of irregularities in the formation of regions and sub-regions of Hamadan province. Research Quarterly of Geographical Data (SEPEHR). 2017;26(103):109-22. doi: 10.22131/sepehr.2017.28897. [Persian].

29. Thompson SK. Sampling. New York: John Wiley & Sons; 2012.

30. Solgi E, Beigmohammadi F, Zamanian A. Application of pollution indices to investigate of heavy metals‏ sequestration in soil (case study of Nahavand cement factory)‎. Appl Soil Res. 2020;8(3):188-201. [Persian].

31. Hakanson L. An ecological risk index for aquatic pollution control: a sedimentological approach. Water Res. 1980;14(8):975-1001. doi: 10.1016/0043-1354(80)90143-8.

32. Ferreira SL, da Silva Junior JB, dos Santos IF, de Oliveira OM, Cerda V, Queiroz AF. Use of pollution indices and ecological risk in the assessment of contamination from chemical elements in soils and sediments – practical aspects. Trends Environ Anal Chem. 2022;35:e00169. doi: 10.1016/j.teac.2022.e00169.

33. Nemerow NL, Agardy FJ. Strategies of Industrial and Hazardous Waste Management. John Wiley & Sons; 1998.

34. Mirzaei M, Marofi S, Solgi E, Abbasi M, Karimi R, Riyahi Bakhtyari HR. Ecological and health risks of soil and grape heavy metals in long-term fertilized vineyards (Chaharmahal and Bakhtiari province of Iran). Environ Geochem Health. 2020;42(1):27-43. doi: 10.1007/s10653-019-00242-5.

35. Pardakhti A, Zahed F. Pollution indices and ecological risk assessment for heavy metals in side soils of interurban roads, Iran. J Environ Sci Stud. 2018;3(3):769-81. [Persian].

36. Zhang S, Chen B, Du J, Wang T, Shi H, Wang F. Distribution, assessment, and source of heavy metals in sediments of the Qinjiang river, China. Int J Environ Res Public Health. 2022;19(15). doi: 10.3390/ijerph19159140.

37. Tajudin NS, Zulkifli M, Miskon MF, Anuar MI, Hashim Z, Faudzi F, et al. Integrated approach of heavy metal evaluation using geostatistical and pollution assessment index in soil of bauxite mining area. Pertanika J Sci Technol. 2022;30(2):1545-66. doi: 10.47836/pjst.30.2.38.

38. US Environmental Protection Agency (EPA). Exposure Factors Handbook (2011 Edition). Washington, DC: EPA; 2011. p. 600.

39. Pour Abbasi H, Payanadeh K, Tadayouni M. Evaluation of some heavy metals and possible health and ecological risk indicators of surface soils of the west of the country: a case study. J Res Environ Health. 2024;10(1):31-47. doi: 10.22038/jreh.2024.24335. [Persian].

40. Rahman MA, Siddique MA, Khan R, Reza A, Khan A, Akbor MA, et al. Mechanism of arsenic enrichment and mobilization in groundwater from southeastern Bangladesh: water quality and preliminary health risks assessment. Chemosphere. 2022;294:133556. doi: 10.1016/j.chemosphere.2022.133556.

41. Touzandejani M, Soffianian A, Mirghafari N, Soleimani M. Assessment of arsenic contamination probability of groundwater in Hamedan-Bahar basin using geostatistical methods. Water Soil. 2017;31(3):874-85. doi: 10.22067/jsw.v31i3.53993. [Persian].

42. Vaziri A, Ghanavati N, Nazarpour A, Babaenejad T. Status, source and environmental pollution assessment of some heavy metals in surface soils of Khuzestan province. J Health. 2021;11(5):664-78. doi: 10.52547/j.health.11.5.664. [Persian].

43. Ghanavati N, Nazarpour A, De Vivo B. Ecological and human health risk assessment of toxic metals in street dusts and surface soils in Ahvaz, Iran. Environ Geochem Health. 2019;41(2):875-91. doi: 10.1007/s10653-018-0184-y.

44. Zhang X, Yan Y, Wadood SA, Sun Q, Guo B. Source apportionment of cadmium pollution in agricultural soil based on cadmium isotope ratio analysis. Appl Geochem. 2020;123:104776. doi: 10.1016/j.apgeochem.2020.104776.

45. Alloway BJ. Heavy Metals in Soils: Trace Metals and Metalloids in Soils and Their Bioavailability. 3^rd ed. Springer Science & Business Media; 2013.

46. Raju NJ. Arsenic in the geo-environment: a review of sources, geochemical processes, toxicity and removal technologies. Environ Res. 2022;203:111782. doi: 10.1016/j.envres.2021.111782.

47. Shahbazi A, Soffianian A, Mirghaffari N. Investigation of the effects of agricultural activities on the accumulation of cadmium, cobalt and chromium in soil. J Environ Sci Technol. 2020;22(8):249-60. [Persian].