Characterization and distribution analysis of microplastic pollutants in the coastal water of the Bay of Bengal, India.

The current study examines the characterization and distribution of microplastics in the coastal waters collected from the Chandipur coast of Odisha, Bay of Bengal, India. Surface and subsurface water samples were systematically collected from ten designated locations within the study area using the grab sampling method. Microplastics were extracted using a density separation and filtration method, followed by visual identification, abundance assessment, and polymer characterization using spectroscopic analysis. The quantification of microplastics in samples ranged from 34.10 to 61.96 particles L-1, with an average of 47 ± 14 particles L⁻¹, indicating variation across sampling locations. Fibers were dominant, making up nearly 46% of total microplastic particles, followed by fragments (23%). The particle size distribution revealed that 1-2 mm size class was the dominant fraction (48%), followed by a subsidiary peak in the <1 mm class (26%). Scanning electron microscopy (SEM) images, acquired at magnifications ranging from 1000x to 5000x, revealed detailed surface morphology of the microplastic samples, characterized by cracks, rough textures, pores, and uneven edges. The Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) results revealed that polyester (42%), high-density polyethylene (35%), and polypropylene (23%) were the predominant polymer types in the recovered microplastics. This study provides region-specific baseline data on the abundance, distribution, and characteristics of microplastics in the coastal waters of the Chandipur coast, of Odisha, Bay of Bengal, India, serving as a valuable reference for future monitoring, risk assessment, and management strategies.