Occurrence and characteristics of microplastics in dug-eell groundwater of the Kandy District, Sri Lanka

Microplastic (MP) pollution is an emerging environmental concern, yet groundwater systems remain inadequately studied, particularly in Sri Lanka. Groundwater, which remains under-researched, is the primary drinking water source for some rural and semi-urban areas in the country. This study aimed to evaluate the occurrence, abundance, and characteristics of MPs in groundwater across Kandy District. Thirty wells representing urban, semi-urban, and agricultural settings were sampled. Microplastics were isolated using oxidative digestion and vacuum filtration, identified by stereomicroscopy, and polymer types confirmed using ATR-FTIR spectroscopy. Microplastics were detected in all wells, with concentrations ranging from 9 to 100 particles L⁻¹ (mean: 28 particles L⁻¹). Fibres were the dominant form, followed by fragments and films. Urban wells showed higher concentrations than semi-urban and agricultural wells, although differences among land-use categories were not statistically significant (F = 1.05, p = 0.365). Polyethylene and polyethylene terephthalate were the most common polymers identified. These preliminary findings demonstrate that groundwater in the Kandy District is vulnerable to MP contamination and emphasize the need for routine groundwater monitoring.