Abstract:
Microplastic plastic particles smaller than 5 millimeters are increasingly detected in freshwater
systems, with potential effects on ecosystems, water treatment operations, and human health. In Sri
Lanka, water reserves such as major reservoirs like Victoria, Randenigala, and Kotmale, as well as
natural lakes such as Koggala and Bolgoda, and river-fed tanks in the dry zone, are especially
vulnerable. This is largely due to rapid urbanization, tourism, aquaculture, and poor solid-waste
management practices. This paper presents a nine-part framework to assess the occurrence, sources,
transport, and risks of microplastics across Sri Lanka’s inland waters. The proposed workflow
brings together field sampling, laboratory characterization using methods such as density separation
and FTIR or Raman confirmation, and geospatial hotspot modeling through techniques like Getis–
Ord Gi* and kernel density estimation. These are further integrated with hydrological drivers and
human pressures. The framework concludes with a tiered risk index designed to help prioritize
interventions for drinking-water intakes, irrigation tanks, and recreational lakes.
