Abstract

Cadmium (Cd) is a highly toxic heavy metal for both plants and animals. Its existence in the agroecosystem is alarming for food security due to its presence in the food chain. The objective of this study was to evaluate “Its persistence in agroecosystems poses serious risks to food safety and ecosystem health to assess Cd contamination risk in wastewater-irrigated soils of Multan, Pakistan. The concentration of Cd and other HMs (Pb, Ni, Zn and Cu) was assessed in 52 soil, plant and wastewater samples. Soil samples were taken from 0-20 cm depths and extracted by AB-DTPA for determination of Cd, Pb, Ni, Zn and Cu. The samples were collected, analyzed and digital maps for the area using GIS (Arc Map 10.3.1) were developed for soil samples. Plant samples were dried and digested in HClO4:HNO3. Soil extract, plants extract and water samples were analyzed using AAS (Analytik Jena nova P400). The concentration of Cd, Pb, Ni, Zn and Cu in soil samples ranged from 0.006-6.62, 0.62-6.23, 0.015-4.23, 0.08-4.47, and 0.09-4.94 mg kg-1 respectively. The average concentration HMs (Cd, Pb, Ni, Zn and Cu) in water samples collected from the study area were 0.011, 0.024, 0.051, 0.066 and 0.142 mg L-1 in canal water samples, 0.0040, 0.019, 0.019, 0.048 and 0.092 mg L-1 in groundwater samples and 0.127, 0.067, 0.032, 0.229 and 0.343 mg L-1 in wastewater samples collected from the area of Multan. HMs concentration in different plant species collected from the area ranged from Cd (0.06-7.27 mg kg-1), Pb (0.18-11.35 mg kg-1) Ni (0.44-12.74 mg kg-1), Zn (0.68-15.50 mg kg-1) and Cu (0.80-14.11 mg kg-1). Pollution indices (Igeo and EF) indicated that soil is contaminated with anthropogenic sources. The mean enrichment factor for the Cd was 8.22 which shows significant enrichment by the anthropogenic sources. While the EF for Pb, Ni and Zn was below the recommended criteria and it illustrated that these metals are naturally present in the soil. The Bioaccumulation factor was found in the sequence of Ni>Zn>Pb>Cu>Cd.  Based on the study finding, the wastewater irrigated area of Multan was polluted with Cd and to some extent Pb, Ni, Zn and Cu. This study seeks to assist authorities and researchers in creating a plan of future studies by using GIS effectively, offering GIS-based maps for the assessment and prioritization of control and remediation solutions in the contaminated region.

Keywords: Heavy Metals, Soil Pollution, GIS Mapping.

References

Adriano, D.C., 2001. Trace elements in terrestrial environments: biogeochemistry bioavailability, and risks of metals. Vol. 860. Springer, New York. 867p.

Aftab, T., Shafiq, T., Khan, B., Chaudhry, M.N., 2011. Physicochemical properties, contamination and suitability of canal water for irrigation, Lahore branch Pakistan. Pakistan Journal of Analytical & Environmental Chemistry 12(1-2): 88-94.

Ahmad, K., Ashfaq, A., Khan, Z. I., Ashraf, M., Akram, N. A., Yasmin, S., Batool, A.I., Sher, M.,, Shad, H.A., Khan, A., Rehman, S.U.,Ullah, M.F., Noorka, I.R., 2016. Health risk assessment of heavy metals and metalloids via dietary intake of a potential vegetable (Coriandrum sativum L.) grown in contaminated water irrigated agricultural sites of Sargodha, Pakistan. Human and Ecological Risk Assessment: An International Journal 22(3): 597–610.

Ahmad, K., Wajid, K., Khan, Z.I., Ugulu, I., Memoona, H., Sana, M., Nawaz, K., Malik, I.S., Bashir, H., Sher, M., 2019 . Evaluation of potential toxic metals accumulation in wheat irrigated with wastewater. Bulletin of Environmental Contamination and Toxicology 102(6):822-828.

Akhtar, S., Iram, S., ul Hassan, M.M., Suther, V., Ahmad, R., 2014. Heavy metal concentration in periurban soils and crops under untreated wastewater. International Journal of Scientific and Engineering Research 5: 523–535.

Akinwunmi, F., Akinhanmi, T.F., Atobatele, Z.A., Adewole, O., Odekunle, K., Arogundade, L.A., Ademuyiwa, O., 2017. Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area, Nigeria. Environmental Toxicology and Pharmacology 49: 21–26.

Ali, S.M., Malik, R.N., 2011. Spatial distribution of metals in top soils of Islamabad City, Pakistan. Environment Monitoring and Assessment 172: 1–16.

AOAC, 2005. Official method of Analysis. 18th Edition. Association of Official Analytical Chemists, Washington DC. Method 935.14 and 992.24.

Bux, R.K., Haider, S.I., Batool, M., Solangi, A.R., Shah, Z., Karimi-Maleh, H., Sen, F., 2022. Assessment of heavy metal contamination and its sources in urban soils of district Hyderabad, Pakistan using GIS and multivariate analysis. International Journal of Environmental Science and Technology 19(8): 7901–7913.

Cui, L.P., Bai, J.F., Shi, Y.H., Yan, S.L., Huang, W.H., Tang, X.Y., 2004. Heavy metals in soil contaminated by coal mining activity. Acta Pedologica Sinica 41(6): 896–904 [in Chinese].

EC, 2001. Commission Regulation (EC) No 466/2001 of 8 March 2001 setting maximum levels for certain contaminants in foodstuffs (Text with EEA relevance.). Official Journal of the European Communities L 77/1. Available at [Access date: 29.04.2025]: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32001R0466

Faheem, M., Shabbir, S., Zhao, J., Kerr, P.G., Sultana, N., Jia, Z., 2020. Enhanced adsorptive bioremediation of heavy metals (Cd2+, Cr6+, Pb2+) by methane-oxidizing epipelon. Microorganisms 8(4): 505.

Faiz, Y., Tufail, M., Javed, M.T., Chaudhry, M.M., Naila-Siddique, 2009. Road dust pollution of Cd, Cu, Ni, Pb and Zn along Islamabad Expressway, Pakistan. Microchemical Journal 92(2): 186–192.

FAO/WHO, 2004. Evaluation of certain food additives and contaminants. Sixty-first report of the Joint FAO/WHO Expert Committee on Food Additives. Geneva. Available at [Access date: Access date: 29.04.2025]: https://iris.who.int/server/api/core/bitstreams/34f83d75-1bc5-4480-b245-c2076fac96f5/content

Ghrefat, H.A., Abu-Rukah, Y., Rosen, M.A., 2011. Application of geoaccumulation index and enrichment factor for assessing metal contamination in the sediments of Kafrain Dam, Jordan. Environmental Monitoring and Assessment 178: 95–109.

Harris, N.S., Taylor, G.J., 2001. Remobilization of cadmium in maturing shoots of near isogenic lines of durum wheat that differ in grain cadmium accumulation. Journal of Experimental Botany 52: 1473–1481.

Hou, D., O'Connor, D., Nathanail, P., Tian, L., Ma, Y., 2017. Integrated GIS and multivariate statistical analysis for regional scale assessment of heavy metal soil contamination: A critical review. Environmental Pollution 231: 1188–1200.

Huang, G., Ding, C., Zhou, Z., Zhang, T., Wang, X., 2019. A tillering application of zinc fertilizer based on basal stabilization reduces Cd accumulation in rice (Oryza sativa L.). Ecotoxicology and Environmental Safety 167: 338–344.

Iqbal, Z., Abbas, F., Ibrahim, M., Ayyaz, M.M., Ali, S., Mahmood, A., 2019. Surveillance of heavy metals in maize grown with wastewater and their impacts on animal health in periurban areas of Multan, Pakistan. Pakistan Journal of Agricultural Sciences 56(2): 321–328.

Islamzade, T., Islamzade, R., Azizov, R., Babayeva, T., Aliyeva, A., Haciyeva, X., Ashurova, N., 2025. Impact of cadmium-contaminated water and irrigation levels on microbiological properties of soils with different textures. Eurasian Journal of Soil Science 14(2): 107–115.

Ismail, A., Riaz, M., Akhtar, S., Ismail, T., Amir, M., Zafar-ul-Hye, M., 2014. Heavy metals in vegetables and respective soils irrigated by canal, municipal waste and tube well waters. Food Additives & Contaminants: Part B 7(3): 213–219.

Jackson, M.L., 1962. Soil Chemical Analysis. Prentice-Hall Inc., New York. 498p.

Kabata-Pendias, A., 2004. Soil–plant transfer of trace elements—an environmental issue. Geoderma 122(2–4): 143–149.

Kabata-Pendias, A., Pendias, H., 2001. Trace Elements in Soils and Plants. 3rd Edition, CRC Press, Boca Raton. 403p.

Kebonye, N.M., Eze, P.N., John, K., Gholizadeh, A., Dajčl, J., Drábek, O., Borůvka, L., 2021. Self-organizing map artificial neural networks and sequential Gaussian simulation technique for mapping potentially toxic element hotspots in polluted mining soils. Journal of Geochemical Exploration 222: 106680.

Khattak, M.A., Ahmed, N., Qazi, M.A., Izhar, A., Ilyas, S., Chaudhary, M.N., Khan, M.S.A., Iqbal, N., Waheed, T., 2012. Evaluation of ground water quality for irrigation and drinking purposes of the areas adjacent to Hudiara industrial drain, Lahore, Pakistan. Pakistan Journal of Agricultural Research 49(4): 549–556.

Kim, J.Y., Oh, S., Park, Y.K., 2020. Overview of biochar production from preservative-treated wood with detailed analysis of biochar characteristics, heavy metals behaviors, and their ecotoxicity. Journal of Hazardous Materials 384: 121356.

Li, L., Gu, W., Li, J., Li, C., Xie, T., Qu, D., Meng, Y., Li, C., Wei, S., 2018. Exogenously applied spermidine alleviates photosynthetic inhibition under drought stress in maize (Zea mays L.) seedlings associated with changes in endogenous polyamines and phytohormones. Plant Physiology and Biochemistry 129: 35–55.

Lone, M.I., Saleem, S., Mahmood, T., Saifullah, K., Hussain, G., 2003. Heavy metal contents of vegetables irrigated by sewage/tubewell water. International Journal of Agriculture and Biology 5(4): 533–535.

MacLean, K.S., Robinson, A.R., MacConnell, H.H., 1987. The effect of sewage-sludge on the heavy metal content of soils and plant tissue. Communications in Soil Science and Plant Analysis 18(11): 1303–1316.

Men, C., Liu, R., Xu, L., Wang, Q., Guo, L., Miao, Y., Shen, Z., 2020. Source-specific ecological risk analysis and critical source identification of heavy metals in road dust in Beijing, China. Journal of Hazardous Materials 388: 121763.

Muller, G., 1969. Index of geoaccumulation in sediments of the Rhine River. GeoJournal 2: 108–118.

Mushtaq, N., Khan, K.S., 2010. Heavy metals contamination of soils in response to wastewater irrigation in Rawalpindi region. Pakistan Journal of Agricultural Sciences 47(3): 215–224.

Olsen, S.R., 1954. Estimation of available phosphorus in soils by extraction with sodium bicarbonate, Circular No. 939. US Department of Agriculture, Washington, D.C. USA. 19p.

Rahman, Z., Singh, V.P., 2019. The relative impact of toxic heavy metals (THMs) (arsenic (As), cadmium (Cd), chromium (Cr)(VI), mercury (Hg), and lead (Pb)) on the total environment: an overview. Environmental Monitoring and Assessment 191: 419.

Randhawa, M.A., Ahmad, G., Anjum, F.M., Asghar, A., Sajid, M.W., 2014. Heavy metal contents and their daily intake in vegetables under peri-urban farming system of Multan, Pakistan. Pakistan Journal of Agricultural Sciences 51(4): 1025–1031.

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.

Rizwan, M., Ali, S., Akbar, M.Z., Shakoor, M.B., Mahmood, A., Ishaque, W., Hussain, A., 2017. Foliar application of aspartic acid lowers cadmium uptake and Cd-induced oxidative stress in rice under Cd stress. Environmental Science and Pollution Research 24: 21938–21947.

Sarwar, N., Saifullah, Malhi, S.S., Zia, M.H., Naeem, A., Bibi, S., Farid, G., 2010. Role of mineral nutrition in minimizing cadmium accumulation by plants. Journal of the Science of Food and Agriculture 90: 925–937.

Sasane, V.V., Kote, A.S., 2022. Groundwater heavy metal contamination mapping using Geographic Information System (GIS): A case of Nashik Thermal Power Station, Eklahare, Nashik (MS), India. In: Advanced Modelling and Innovations in Water Resources Engineering, Lecture Notes in Civil Engineering. Rao, C.M., Patra, K.C., Jhajharia, D., Kumari, S. (Eds.). Vol 176. Springer, Singapore. pp. 477–492.

Soltanpour, P.N., 1985. Use of AB-DTPA soil test to evaluate elemental availability and toxicity. Communications in Soil Science and Plant Analysis 16: 323–338.

Sulieman, M.M., Elfaki, J.T., Adam, M.M., Dafalla, M.S., Ali, S.H., Ahmed, H.M., Ali, M.E., 2017. Assessment of heavy metals contamination in the Nile River water and adjacent sediments: A case study from Khartoum City and Nile River State, Sudan. Eurasian Journal of Soil Science 6(3): 285-294.

Sutherland, R.A., 2000. Bed sediment-associated trace metals in an urban stream, Oahu, Hawaii. Environmental Geology 39(6): 611–627.

Topi, T., Bani, A., Malltezi, J., Sulejman, S., 2012. Heavy metals in soil, sediments, mussels and water from Butrinti Lagoon (Albania). Fresenius Environmental Bulletin 21(10A): 3042–3051.

US Salinity Laboratory Staff, 1954. Diagnosis and improvement of saline and alkali soils. US Department of Agriculture Handbook 60, Washington, DC.

Wadood, S.A., Sharif, M.K., Ashraf, M.N., Ejaz, R., Kosar, G., Azeem, M., Murtaza, G., 2021. Estimation of heavy metals and associated health risk in selected vegetables grown in peri-urban areas of Multan and Rawalpindi, Pakistan: Estimation of heavy metals in vegetables. Biological Sciences - PJSIR 64(1): 55–63.

Xu, X., Cao, X., Zhao, L., 2013. Comparison of rice husk- and dairy manure-derived biochars for simultaneously removing heavy metals from aqueous solutions: Role of mineral components in biochars. Chemosphere 92(8): 955–961.

Younis, U., Malik, S.A., Rizwan, M., Qayyum, M.F., Ok, Y.S., Shah, M.H.R., Rehman, R.A., Ahmad, N., 2016. Biochar enhances the cadmium tolerance in spinach (Spinacia oleracea) through modification of Cd uptake and physiological and biochemical attributes. Environmental Science and Pollution Research 23: 21385–21394.

Yuan, G.L., Sun, T.H., Han, P., Li, J., Lang, X.X., 2014. Source identification and ecological risk assessment of heavy metals in topsoil using environmental geochemical mapping: Typical urban renewal area in Beijing, China. Journal of Geochemical Exploration 136: 40–47.

Zhang, J., Liu, C.L., 2002. Riverine composition and estuarine geochemistry of particulate metals in China—Weathering features, anthropogenic impact and chemical fluxes. Estuarine, Coastal and Shelf Science 54(6): 1051–1070.

Zhang, Z., Lu, Y., Li, H., Tu, Y., Liu, B., Yang, Z., 2018. Assessment of heavy metal contamination, distribution and source identification in the sediments from the Zijiang River, China. Science of the Total Environment 645: 235–243.

Zhao, H., Liu, P., Qiao, B., Wu, K., 2021. The spatial distribution and prediction of soil heavy metals based on measured samples and multi-spectral images in Tai Lake of China. Land 10(11): 1227.

Zhou, G., Liu, C., Chu, L., Tang, Y., Luo, S., 2016. Rapid and efficient treatment of wastewater with high-concentration heavy metals using a new type of hydrogel-based adsorption process. Bioresource Technology 219: 451–457.