Spatial Distribution and Ecological Risk Assessment of Microplastics in the Inner-Shelf Sediments of Sonadia Island, Bangladesh

Author: Md. Juwel Rana, M. Shahidul Islam, Asib Ahmed, Mahmud Al Noor Tushar, Rihana Parvin Nipa
DOI: doi.org/10.70279/bmj-v3-1012

Microplastic (Mp) pollution has raised widespread concerns due to its prevalence and potential risks to humans and ecosystems. The present study aims at investigating the spatial distribution and ecological risk associated with microplastics (MPs) contamination in the inner-shelf sediments adjacent to the Sonadia Island, Bangladesh. A total of fifteen sediment samples from five locations were collected using Van Veen Grab sample, covering an area of about 15km2 near shelf area of the Island. The abundance, morphology and constituent polymer types of MPs were measured using light microscopy and Fourier Transform Infrared Spectroscopy (FT-IR). The investigation reveals that the MPs concentration ranges from 28 MPs/100g (in sampling site S2) to 41 MPs/100g (in sampling site S5) with an average value of 35 MPs/100gm, where Fiber constitutes the dominant morpho-type(92.5%), followed by Film (2.7%), Foam (2.7%) and Fragments (2.1%). FT-IR spectrum show that polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) are the constituent polymers of the recorded MPs. The average values of the Polymer Hazard Index (PHI) and Pollution Load Index (PLI) indicate that the shelf sediments in the study area face moderate to high ecological risk from microplastic contamination. Our findings provide baseline data on microplastic pollution in the inner-shelf sediments near Sonadia Island and offer preliminary quantitative assessments of ecological risk, enhancing understanding of the fate, transport and ecological impacts of microplastics.