Kumari Akanksha, Chakraborty Sukalyan
Department of Civil and Environmental Engineering, Birla Institute of Technology, Mesra, Jharkhand, India, 835215.
Environ Monit Assess. 2024 Dec 30;197(1):111. doi: 10.1007/s10661-024-13585-z.
Microplastics (MPs) seriously threaten soil quality and crop health, particularly in agricultural systems using plastic mulch and sewage sludge, with their abundance being strongly influenced by soil properties such as texture, structure, and chemical content. Considering this, the present study assessed MP contamination in arid agricultural soils, focusing on their abundance, morphology, composition, and association with heavy metals to evaluate environmental risks. Soil samples were collected from ten plastic-mulched fields and a control site across a 50 sq. km area. MPs were isolated using density separation and hydrogen peroxide digestion, with morphology categorized through microscopy and polymer composition analysed via FTIR. ICP-OES was used for elemental analysis. Statistical methods, including ANOVA, Pearson's correlation, scatter plots, and PCA, were applied to examine the influence of soil quality on MP levels. Results showed significantly higher MP concentrations in mulched fields (1412 ± 529 particles) compared to the control (72 ± 41 particles), with MPs primarily consisting of fibres, films, fragments, and microbeads. Positive correlations were observed between MPs and soil properties such as clay content, moisture, and organic matter content. FTIR analysis identified eight polymer types, while heavy metals, mainly Fe and Ni, were found to accumulate within MPs. MP counts were positively correlated with mulching duration (r = 0.46 to 0.94), indicating increased contamination over time. These findings emphasize the role of soil properties on MP retention and potential risks posed to soil health and environmental sustainability, stressing the need for strategies to mitigate MP contamination in agriculture.
微塑料（MPs）严重威胁土壤质量和作物健康，特别是在使用塑料薄膜和污水污泥的农业系统中，其丰度受到土壤质地、结构和化学含量等土壤性质的强烈影响。考虑到这一点，本研究评估了干旱农业土壤中的微塑料污染情况，重点关注其丰度、形态、组成以及与重金属的关联，以评估环境风险。在一个50平方公里的区域内，从十个使用塑料薄膜的农田和一个对照地点采集了土壤样本。通过密度分离和过氧化氢消解分离出微塑料，通过显微镜对其形态进行分类，并通过傅里叶变换红外光谱仪（FTIR）分析聚合物组成。使用电感耦合等离子体发射光谱仪（ICP - OES）进行元素分析。应用包括方差分析（ANOVA）、皮尔逊相关性分析、散点图和主成分分析（PCA）在内的统计方法，研究土壤质量对微塑料含量的影响。结果显示，与对照（72±41个颗粒）相比，使用塑料薄膜的农田中微塑料浓度显著更高（1412±529个颗粒），微塑料主要由纤维、薄膜、碎片和微珠组成。观察到微塑料与土壤性质如粘土含量、湿度和有机质含量之间存在正相关。傅里叶变换红外光谱分析确定了八种聚合物类型，同时发现重金属（主要是铁和镍）在微塑料中积累。微塑料数量与覆膜持续时间呈正相关（r = 0.46至0.94），表明随着时间推移污染加剧。这些发现强调了土壤性质对微塑料留存的作用以及对土壤健康和环境可持续性构成的潜在风险，强调需要采取策略减轻农业中的微塑料污染。
