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Abstract

Contamination of terrestrial systems by microplastics (MPs) has become a critical environmental hazard, but detection of such contaminants in a complex soil system is a challenge for conventional analytical techniques. This research aims to assess the potential of Laser-Induced Breakdown Spectroscopy (LIBS) for the detection and differentiation of different types of microplastics, including HDPE, LDPE, PP, PS, and PVC, dispersed in the soil of Al Najaf, Iraq. Soil samples were collected from different functional zones, namely, Industrial, Commercial, Agricultural, Residential, and Roadside, at the surface level and 30 cm depth. Detection was done by measuring the intensity of the C/H ratio, where the Carbon emission line was fixed at 247.86 nm, and the Hydrogen emission line was fixed at 388.47 nm, and the results were compared with the atomic spectra given in the NIST database. The results showed a strong relationship between different types of polymers and different functional zones, where the industrial zone was showed spectral signatures most consistent with HDPE, the roadside was showed a predominance of PS spectral fingerprints, and the agricultural zone showed consistency in PVC vertical distribution. Although the residential prediction was in favor of LDPE, the empirical results pointed towards PET and PVC, which was due to the effect of synthetic fibers and debris. The conclusion of the research was that the proposed method of LIBS, which uses the ratio method, may help reduce the influence of the background matrix interferences of carbonate-rich and gypsiferous soils, thereby providing a cost-effective and rapid solution for the environmental analysis of the diffusion of microplastics in arid terrestrial environments.

References

[1] Chia RW, Lee J-Y, Kim H, Jang J. Microplastic pollution in soil and groundwater: a review. Environ Chem Lett 2021; 19(6):4211—24.

[2] Gündogdu S, Akca MO, Gursoy M, Yılmaz M, Zhang X, Rodríguez-Seijo A, Bibi A, Di Gioia ML, Velimirovic M. Microplastics in soil: a comprehensive review of analytical techniques. Front Soil Sci 2025;5:1614075.

[3] Osman AI, Hosny M, Eltaweil AS, Omar S, Elgarahy AM, Farghali M, Yap P-S, Wu Y-S, Nagandran S, Batumalaie K. Microplastic sources, formation, toxicity and remediation: a review. Environ Chem Lett 2023;21(4):2129—6

[4] Mohasin M, Habib K, Rao PS, Ahmad M, Siddiqui S. Microplastics in agricultural soils: sources, impacts, and mitigation strategies. Environ Monit Assess 2025;197(6):684.

[5] Chia R, Lee J, Cha J, Çelen-Erdem _ I. A comparative study of soil microplastic pollution sources: a review. Environmental Pollutants and Bioavailability. Environ Pollut Bioavailab 2023;38(1).

[6] Chen Z, Carter LJ, Banwart SA, Kay P. Microplastics in soil—plant systems: current knowledge, research gaps, and future directions for agricultural sustainability. Agronomy 2025;15(7):1519.

[7] Yu H, Zhang Y, Tan W, Zhang Z. Microplastics as an emerging environmental pollutant in agricultural soils: effects on ecosystems and human health. Front Environ Sci 2022;10:855292.

[8] Zhou C, Chen Z, Nasr M, Osman AI, Lai ZY, Yiin CL, Chin BLF, Yap P-S. Monitoring and Assessment Techniques for Microplastics. In: Microplastics in African and Asian environments: the influencers, challenges, and solutions. Springer; 2024. p. 601—46.

[9] Almola M. Study of the presence of microplastic particles and heavy metals in street dust on the right side of Mosul city/Iraq. College of Basic Education Research Journal 2025; 21(2):588—614.

[10] Abbas OR, Al-Paruany KB, Mashjel MH. Distribution of Heavy metals, Polycyclic aromatic hydrocarbons, Microplastics particles, and their potential contamination of soil in a selected area in Baghdad City, Iraq. Iraqi J Sci 2025; 66(9):3818—34.

[11] Al-Khalidy HI, Al-Haidarey MJS. Determination of polystyrene concentrations in Kufa River/Iraq. BIO web of conferences, 108. EDP Sciences; 2024. p. 04008.

[12] S. Jalal, "Exploring the distribution of microplastics and heavy metals in agricultural soils and the evaluation of risk indices in erbil city..

[13] Al-Hussayni RS, Al-Ahmady KK, Mhemid RKS. Assessment of indoor microplastic particles pollution in selected sites of Mosul City. Journal of Ecological Engineering 2023;24(9).

[14] Al-Imara EA, Al-Mayyahi BA, Al-Ankush MA, Al-Shatty SM. Biodegradation of oil-based plastic wastes by bacteria isolated from fish breeding tanks. Iraqi J Sci 2023:513—24.

[15] Al-Rashedy HSMA, Al-Shanoona RA, Mame SOO. Plastic granules and their polluting effect on plant growth. Journal of Ecological Engineering 2025;26(2):319—26.

[16] Ati EM, Hano SH, Ajmi RN, Latif AS. Laser Induced Spectroscopy (LIBS) Technology and Environmental Risk Index (RI) to Detect Microplastics in Drinking Water in Baghdad, Iraq. Nat Environ Pollut Technol 2024;23(4):2441—6.

[17] Yaqoob MM, Somlyai I, Berta C, Bacsi  I, Al-Tayawi AN, AlAhmady KK, Mohammed RH, Alalami O, Grigorszky I. The impacts of land use and seasonal effects on phytoplankton taxa and physical-chemical variables in the Tigris River within the City of Mosul. Water 2023;15(6):1062.

[18] Almola MA, Al-Ahmady KK, Mhemid RKS. An investigation of microplastic occurrence and heavy metals concentrations in street dust on the left side of Mosul City, Iraq. Journal of Ecological Engineering 2024;25(9):116—32.

[19] Gianico A, Braguglia CM, Gallipoli A, Montecchio D, Mininni G. Land application of biosolids in Europe: possibilities, con-straints and future perspectives. Water 2021; 13(1):103.

[20] Popoola LT, Olawale TO, Salami L. A review on the fate and effects of contaminants in biosolids applied on land: Hazards and government regulatory policies. Helyon 2023;9(10).

[21] Cabernard L, Roscher L, Lorenz C, Gerdts G, Primpke S. Comparison of Raman and Fourier transform infrared spectroscopy for the quantification of microplastics in the aquatic environment. Environmental science technology 2018;52(22):13279—88.

[22] Wang Z, Wang X, Hu C, Ge T, Wang L, Xing J, He X, Zhao Y. Comparative evaluation of analytical techniques for quantifying and characterizing polyethylene microplastics in farmland soil samples. Agriculture 2024;14(4):554.

[23] Park SY, Kim CG. A comparative study on the distribution behavior of microplastics through FT-IR analysis on different land uses in agricultural soils. Environ Res 2022; 215:114404.

[24] Wangeci AN. Applying Laser-Induced Breakdown Spectroscopy for Rapid Large-Scale Determination of Soil Organic Carbon. Soil Science Cases 2025;2025:sscs20250005.

[25] Erler A, Riebe D, Beitz T, Lohmannsr € oben € H-G, Leenen M, Patzold € S, Ostermann M, Wojcik  M. Mobile laser-induced breakdown spectroscopy for future application in precision agriculture―A case study. Sensors 2023;23(16):7178.

[26] Mahmood EJ, Al-Sultani MMM. Detection of pollutants in soil using laser-induced breakdown spectroscopy (libs). AlBahir 2024;5(2):9.

[27] Chen Y, Gao W, Han B, Wu T, Yan Y, Chen G, Liu Y. Online in situ detection of atmospheric microplastics based on laserinduced breakdown spectroscopy. J Laser Appl 2025;37(1).

[28] Huang Y, Harilal SS, Bais A, Hussein AE. Progress toward machine learning methodologies for laser-induced breakdown spectroscopy with an emphasis on soil analysis. IEEE Trans Plasma Sci 2023;51(7):1729—49.

[29] Osman AI, Elgarahy AM, Mehta N, Al-Muhtaseb AaH, AlFatesh AS, Rooney DW. Facile synthesis and life cycle assessment of highly active magnetic sorbent composite derived from mixed plastic and biomass waste for water remediation. ACS Sustainable Chem Eng 2022;10(37): 12433—47.

[30] Mahdee MS, Saleh ZA, Taban T. Laser-induced breakdown spectroscopy (libs): an innovative tool for elemental analysis of soils. 2016.

[31] Jelínkova  H. Lasers for medical applications: diagnostics, therapy and surgery. Elsevier; 2013.

[32] Fricke-Begemann C, Sturm V, Noll R. Laser-Induced Breakdown Spectroscopy. In: Tailored light 2: laser applications. Springer; 2023. p. 833—68.

[33] Ali TS, Fakhraldin MK. Soil parameters analysis of Al-Najaf City in Iraq: case study. J Geotech Eng 2016;3(1):56—62.

[34] Al-Bayati M, Al-Obaydi B. Study of the mineral analysis of some gypsiferous soils in Salah al-Din and Najaf governorates using X-ray diffraction powder technique. Tikrit Journal for Agricultural Sciences 2023;23(2):10—24.

[35] Mutlag NH, Al Hatimi IA. Evaluation of some of chemical and physical properties and some nutrients in the soils and water of Bahr al-Najaf Depression-Iraq. Int J Health Sci 2022;6(S4):5533—47.

[36] Yacoub SY. Geomorphology of the Mesopotamia plain. Iraqi Bulletin of Geology 2011;(4):7—32.

[37] Mhaimeed AS. Soil resources of Iraq. Soil Resources of Mediterranean Caucasus Countries 2013;98.

[38] Weber CJ, Weihrauch C, Opp C, Chifflard P. Investigating microplastic dynamics in soils: Orientation for sampling strategies and sample pre-procession. Land Degrad Dev 2021;32(1):270—84.

[39] Sissakian V, Al-Ansari N, Adamo N. Geomorphology, stratigraphy and tectonics of the mesopotamian plain, Iraq: a critical review. Geotectonics 2021;55(1):135—60.

[40] Araujo CF, Nolasco MM, Ribeiro AM, Ribeiro-Claro PJ. Identification of microplastics using Raman spectroscopy: Latest developments and future prospects. Water Res 2018; 142:426—40.

[41] Unnikrishnan V, Choudhari K, Kulkarni SD, Nayak R, Kartha V, Santhosh C. Analytical predictive capabilities of laser induced breakdown spectroscopy (LIBS) with principal component analysis (PCA) for plastic classification. RSC Adv 2013;3(48):25872—80.

[42] Gregoire  S, Boudinet M, Pelascini F, Surma F, Detalle V, Holl Y. Laser-induced breakdown spectroscopy for polymer identification. Anal Bioanal Chem 2011;400(10):3331—40.

[43] Kim E, Choi WZ. Real-time identification of plastics by types using laser-induced breakdown spectroscopy. J Mater Cycles Waste Manag 2019;21(1):176—80.

[44] Gondal MA, Siddiqui MN. Identification of different kinds of plastics using laser-induced breakdown spectroscopy for waste management. J Environ Sci Health Part A 2007;42(13): 1989—97.

[45] Junjuri R, Gundawar MK. A low-cost LIBS detection system combined with chemometrics for rapid identification of plastic waste. Waste Management 2020;117:48—57.

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