Volume 14, Issue 2 (9-2026)
J Environ Health Eng 2026, 14(2): 184-205 |
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Alaei H, Mafigholami R, Khoramipour S, MoradiGhiasabadi B, Moghimi H. Characterization and Biodegradation Feasibility of Microplastics in Agricultural Soils: A Case Study from Southern Tehran Farmlands, Iran. , J Environ Health Eng. 2026; 14 (2) :184-205
URL: http://jehe.abzums.ac.ir/article-1-1162-en.html
URL: http://jehe.abzums.ac.ir/article-1-1162-en.html
Hassan Alaei1 
, Roya Mafigholami *2 , Sanaz Khoramipour1 , Behnaz MoradiGhiasabadi3 , Hamid Moghimi4
, Roya Mafigholami *2 , Sanaz Khoramipour1 , Behnaz MoradiGhiasabadi3 , Hamid Moghimi4
1- Department of Environment, WT.C., Islamic Azad University, Tehran, Iran
2- Department of Environment, WT.C., Islamic Azad University, Tehran, Iran ,r.mafigholami@wtiau.ac.ir
3- Department of Environment, Damavand Branch, Islamic Azad University, Damavand, Iran
4- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
2- Department of Environment, WT.C., Islamic Azad University, Tehran, Iran ,
3- Department of Environment, Damavand Branch, Islamic Azad University, Damavand, Iran
4- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
Abstract: (6 Views)
Background: Microplastics are emerging, persistent pollutants that increasingly accumulate in agricultural soils, where they may impair soil functioning and threaten ecosystem and food security. This study investigated the occurrence of microplastics and assessed the biodegradation potential of indigenous microorganisms in agricultural soils of the Varamin Plain, Iran.
Methods: Soil samples were collected from five agricultural fields during warm and cold seasons at two depths (surface and subsurface). Microplastics were extracted using density separation combined with oxidative removal of organic matter, and particles were identified and quantified by stereomicroscopy. Statistical analyses included ANOVA, independent‑samples t‑tests, Pearson correlation, and linear regression. For biodegradation assessment, indigenous microorganisms were enriched on common polymers, and molecular identification was performed via PCR and 16S rRNA gene sequencing. Surface alterations of the polymers were examined using FESEM and FTIR.
Results: The mean microplastic concentration was 312.49 particles per kilogram of soil. The most abundant size class was 5-20 µm, and fibers were the dominant morphological type (42.38%). No significant differences in microplastic abundance were detected between seasons, depths, particle size classes, or fields (P>0.05). Four bacterial strains Lysinibacillus boronitolerans, Pseudomonas stutzeri, Bacillus pacificus, and Microbacterium hibisci were identified, each inducing limited morphological and structural changes on microplastic surfaces.
Conclusion: Agricultural soils in the Varamin Plain are uniformly contaminated with microplastics yet host indigenous microbial communities with a measurable, albeit slow, capacity to initiate biodegradation. Strengthening wastewater management, implementing continuous monitoring, and harnessing this biodegradation potential may help mitigate long‑term environmental risks.
Methods: Soil samples were collected from five agricultural fields during warm and cold seasons at two depths (surface and subsurface). Microplastics were extracted using density separation combined with oxidative removal of organic matter, and particles were identified and quantified by stereomicroscopy. Statistical analyses included ANOVA, independent‑samples t‑tests, Pearson correlation, and linear regression. For biodegradation assessment, indigenous microorganisms were enriched on common polymers, and molecular identification was performed via PCR and 16S rRNA gene sequencing. Surface alterations of the polymers were examined using FESEM and FTIR.
Results: The mean microplastic concentration was 312.49 particles per kilogram of soil. The most abundant size class was 5-20 µm, and fibers were the dominant morphological type (42.38%). No significant differences in microplastic abundance were detected between seasons, depths, particle size classes, or fields (P>0.05). Four bacterial strains Lysinibacillus boronitolerans, Pseudomonas stutzeri, Bacillus pacificus, and Microbacterium hibisci were identified, each inducing limited morphological and structural changes on microplastic surfaces.
Conclusion: Agricultural soils in the Varamin Plain are uniformly contaminated with microplastics yet host indigenous microbial communities with a measurable, albeit slow, capacity to initiate biodegradation. Strengthening wastewater management, implementing continuous monitoring, and harnessing this biodegradation potential may help mitigate long‑term environmental risks.
Keywords: Microplastics, agricultural soils, biodegradation, indigenous microorganisms, Varamin Plain
Type of Study: Research |
Subject:
Special
Received: 2026/04/19 | Accepted: 2026/08/19 | Published: 2026/09/20
Received: 2026/04/19 | Accepted: 2026/08/19 | Published: 2026/09/20
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