Seasonal MSW characterization and ecological risk assessment near an open dumpsite in Dimapur, Northeast India

Open dumpsites pose significant environmental risks by introducing toxic metals into the surrounding soil, water, and vegetation. A study was undertaken to assess seasonal variations in municipal solid waste (MSW) composition and heavy metal contamination in soil, vegetation, and sediments near an open dumpsite in Dimapur, India. Waste characterization was conducted seasonally to determine the physical and chemical composition of MSW, while heavy metals (Fe, Cu, Cd, Zn, Mn, Pb) were quantified using atomic absorption spectrophotometer (AAS). Pollution levels were evaluated through multiple indices, including contamination factor (CF), pollution load index (PLI), enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk index (PERI). Additionally, the transfer factor (TF) was used to assess metal uptake by local vegetation. Results showed significantly elevated concentrations of Cd and Pb, with CF for Cd reaching 2217.5 and PLI values ranging from 1.0 to 5.6, indicating moderate to severe pollution. EF and Igeo analyses confirmed strong anthropogenic inputs, particularly for Cd (EF > 40) and Pb (Igeo up to 5.6). PERI identified Cd as the major ecological risk (RI > 300), while TF analysis revealed bioaccumulation of Pb in edible plants like chilli (TF = 1.295), raising food chain concerns. These results underscore the urgent need for remediation and improved waste management strategies. The methodology and findings provide transferable insights applicable to other rapidly urbanizing regions facing similar waste management challenges.