Prasad Girija, Mohanty Smita, Chakraborty Paromita, Bharat Girija K
Central Institute of Petrochemical Engineering and Technology (CIPET): School for Advanced Research in Polymers (SARP)-Laboratory for Advanced Research in Polymeric Materials (LARPM), Patia, Bhubaneswar, Odisha, 751024, India.
SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, 603203, India.
Integr Environ Assess Manag. 2025 Jul 1;21(4):843-857. doi: 10.1093/inteam/vjaf011.
Microplastics (MPs) have become a notable concern and are released into the environment through the disposal or fragmentation of large plastics. Rivers have been the major pathways for MPs present in the oceans, which significantly affects the marine environment. In this study, water samples were collected from the upper stream and downstream of the Damanganga and Tapi rivers across different sites in the state of Gujarat, India, for exploration of MP contamination. Additionally, samples were collected from Dumas Beach to detect the presence of MPs. Microplastics were extracted from the samples through sieving, density separation, and wet peroxide oxidation techniques, and were subsequently analyzed using μ-FTIR (micro-Fourier transform infrared spectroscopy), optical microscopy, pyrolysis gas chromatography-mass spectrometry (Py-GCMS) and scanning electron microscopy (SEM). The concentration of MPs was also quantified from each stretch of the Damanganga and Tapi rivers as well as Dumas Beach. Findings revealed that the Damanganga showed a higher concentration (3.53 particles/L) of MPs compared with the others. Further, optical microscopy and μ-FTIR analysis confirmed the presence of MPs such as polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyethylene (PE), and polymethyl methacrylate (PMMA). Pyrolysis products of PP, PS, and polyamide (PA) were detected from Py-GCMS studies. Additionally, SEM images revealed that MPs were subjected to weathering, oxidation, and atmospheric deposition over the years. The study additionally confirmed the flux of MPs in both rivers and the beach due to anthropogenic and industrial effects. Risk assessment of MPs was performed using the pollutant loading index (PLI), which indicated that the overall MP pollution in the studied sites was marginal. Nevertheless, the PLI scores revealed that Damanganga was the most prone to MP pollution among the three study sites.
微塑料（MPs）已成为一个显著的问题，通过大塑料的处置或破碎释放到环境中。河流一直是海洋中微塑料的主要传输途径，这对海洋环境有重大影响。在本研究中，从印度古吉拉特邦不同地点的达曼甘加河和塔皮河的上游和下游采集水样，以探索微塑料污染情况。此外，还从杜马斯海滩采集样本以检测微塑料的存在。通过筛分、密度分离和湿过氧化氢氧化技术从样本中提取微塑料，随后使用μ - 傅里叶变换红外光谱（μ - FTIR）、光学显微镜、热解气相色谱 - 质谱联用仪（Py - GCMS）和扫描电子显微镜（SEM）进行分析。还对达曼甘加河和塔皮河的每一段以及杜马斯海滩的微塑料浓度进行了定量。研究结果显示，与其他河流相比，达曼甘加河的微塑料浓度更高（3.53个颗粒/升）。此外，光学显微镜和μ - FTIR分析证实存在聚丙烯（PP）、聚苯乙烯（PS）、聚对苯二甲酸乙二酯（PET）、聚乙烯（PE）和聚甲基丙烯酸甲酯（PMMA）等微塑料。从Py - GCMS研究中检测到了PP、PS和聚酰胺（PA）的热解产物。此外，SEM图像显示这些微塑料多年来受到了风化、氧化和大气沉降的影响。该研究还证实了由于人为和工业影响，微塑料在两条河流和海滩中的通量情况。使用污染物负荷指数（PLI）对微塑料进行了风险评估，结果表明研究地点的总体微塑料污染程度较轻。然而，PLI分数显示，在三个研究地点中，达曼甘加河最容易受到微塑料污染。
