{"title":"Silent contaminants in a vanishing wetland: microplastics and their ecological risks in the Gavkhoni Wetland sediments.","authors":"MohammadMehdi Fowzi, Ehsan Jafarpisheh, Gangadhar Andaluri, Afshin Ebrahimi, Karim Ebrahimpour","doi":"10.1007/s10653-025-02782-5","DOIUrl":null,"url":null,"abstract":"<p><p>Microplastics (MPs), as emerging organic pollutants, pose significant threats to ecosystems. This study investigated the presence and ecological risks of MPs in the sediments of the Gavkhoni Wetland, a recently desiccated yet ecologically important terminal basin of the Zayandeh-Rud River in central Iran. Fifty sediment samples were collected across three hydrologically distinct zones. An optimized extraction protocol using 0.05 M Fe(II) and H<sub>2</sub>O<sub>2</sub> digestion followed by ZnCl<sub>2</sub>-based density separation was applied. MPs were quantified via stereomicroscopy and characterized using Micro-Raman spectroscopy. Three indices, Polymer Hazard Index (PHI), Pollution Load Index (PLI), and Pollution Risk Index (PRI), were employed to assess ecological risk. MP concentrations averaged 43,562.5 ± 9293.2, 21,187.5 ± 5806.9, and 9522.2 ± 3163.9 items/kg in Zones 1-3, respectively, with an overall mean of 24,148 ± 15,644.6 items/kg. Fragments were predominant, and 100-500 µm particles were most common. Polyethylene, polypropylene, and polystyrene were the dominant polymers. PHI, PLI, and PRI values categorized the site under 'Considerable,' 'Polluted,' and 'Dangerous' ecological risk levels, respectively. These results highlight severe MP contamination in a vulnerable dryland ecosystem and underscore the urgent need for targeted environmental management to address this emerging threat in arid and semi-arid wetlands.</p>","PeriodicalId":11759,"journal":{"name":"Environmental Geochemistry and Health","volume":"47 11","pages":"469"},"PeriodicalIF":3.8000,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Geochemistry and Health","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1007/s10653-025-02782-5","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Microplastics (MPs), as emerging organic pollutants, pose significant threats to ecosystems. This study investigated the presence and ecological risks of MPs in the sediments of the Gavkhoni Wetland, a recently desiccated yet ecologically important terminal basin of the Zayandeh-Rud River in central Iran. Fifty sediment samples were collected across three hydrologically distinct zones. An optimized extraction protocol using 0.05 M Fe(II) and H2O2 digestion followed by ZnCl2-based density separation was applied. MPs were quantified via stereomicroscopy and characterized using Micro-Raman spectroscopy. Three indices, Polymer Hazard Index (PHI), Pollution Load Index (PLI), and Pollution Risk Index (PRI), were employed to assess ecological risk. MP concentrations averaged 43,562.5 ± 9293.2, 21,187.5 ± 5806.9, and 9522.2 ± 3163.9 items/kg in Zones 1-3, respectively, with an overall mean of 24,148 ± 15,644.6 items/kg. Fragments were predominant, and 100-500 µm particles were most common. Polyethylene, polypropylene, and polystyrene were the dominant polymers. PHI, PLI, and PRI values categorized the site under 'Considerable,' 'Polluted,' and 'Dangerous' ecological risk levels, respectively. These results highlight severe MP contamination in a vulnerable dryland ecosystem and underscore the urgent need for targeted environmental management to address this emerging threat in arid and semi-arid wetlands.
期刊介绍：
Environmental Geochemistry and Health publishes original research papers and review papers across the broad field of environmental geochemistry. Environmental geochemistry and health establishes and explains links between the natural or disturbed chemical composition of the earth’s surface and the health of plants, animals and people.
Beneficial elements regulate or promote enzymatic and hormonal activity whereas other elements may be toxic. Bedrock geochemistry controls the composition of soil and hence that of water and vegetation. Environmental issues, such as pollution, arising from the extraction and use of mineral resources, are discussed. The effects of contaminants introduced into the earth’s geochemical systems are examined. Geochemical surveys of soil, water and plants show how major and trace elements are distributed geographically. Associated epidemiological studies reveal the possibility of causal links between the natural or disturbed geochemical environment and disease. Experimental research illuminates the nature or consequences of natural or disturbed geochemical processes.
The journal particularly welcomes novel research linking environmental geochemistry and health issues on such topics as: heavy metals (including mercury), persistent organic pollutants (POPs), and mixed chemicals emitted through human activities, such as uncontrolled recycling of electronic-waste; waste recycling; surface-atmospheric interaction processes (natural and anthropogenic emissions, vertical transport, deposition, and physical-chemical interaction) of gases and aerosols; phytoremediation/restoration of contaminated sites; food contamination and safety; environmental effects of medicines; effects and toxicity of mixed pollutants; speciation of heavy metals/metalloids; effects of mining; disturbed geochemistry from human behavior, natural or man-made hazards; particle and nanoparticle toxicology; risk and the vulnerability of populations, etc.
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