A study of microplastics in water and sediments of Lakes around Dhaka city

Microplastics, plastic particles smaller than 5 mm, pose a growing threat to aquatic ecosystems due to their persistence and potential bioaccumulation. While most studies focus on marine systems, limited attention has been given to freshwater environments, particularly in South Asia. This study investigates the presence, distribution, and characterisation of microplastics in water and sediment samples from four urban lakes in Dhaka City, Bangladesh: Dhanmondi, Hatirjheel, Gulshan, and Banani Lakes. Samples were analysed using visual identification, Fourier-transform infrared spectroscopy (FTIR), and spectral matching software. Results revealed an average of 1.2 microplastic particles per litre of water and 13.67 particles per kilogram of sediment. Fibres were the most common type, with black and white being dominant in colour. Approximately 20% of the particles measured between 0.1 and 1 mm. FTIR identified polymers such as poly(methyl methacrylate), poly(tetrafluoroethylene), and poly(ethylene terephthalate). Spatial variations in microplastic abundance were observed, with Gulshan Lake exhibiting the highest levels and Banani Lake the lowest, likely due to differences in local land use and proximity to industrial zones. This study contributes to the growing body of research on microplastic pollution in freshwater systems and underscores the urgent need for monitoring and pollution control strategies in urban water bodies.