Municipal solid waste composition in Jos Metropolis: Seasonal and Metropolis-wide characterization

Municipal solid waste (MSW) generation is increasing rapidly in developing countries, yet reliable city-scale composition data remain limited, constraining sustainable waste management planning. This study presents a detailed metropolis-wide and seasonal characterisation of MSW in Jos metropolis, Nigeria. The city, which is rapidly urbanizing, faces challenge of low waste collection efficiency and heavy dependance on open dumping. A stratified sampling approach was adopted, covering Jos North and Jos South Local Government Areas. waste samples were collected from four major dumpsites to capture spatial and socio-economic variability. Characterisation was carried out over ten months (April 2024–January 2025) to account for seasonal changes. Results revealed that food and putrescible waste accounted for 38.0% of total MSW, increasing to 44.3% with wood waste, confirming the dominance of biodegradable materials. Polythene and plastics accounted for 16.18% and 2.31%, respectively, indicating increasing packaging waste linked to urban transition. Notable seasonal variation was observed in waste properties, with bulk density decreasing from 310.25 kg/m³ in Season 1 to 222.92 kg/m³ in Season 3 (annual mean: 272.63 kg/m³). The findings highlight an organic-rich waste stream with distinct local characteristics. This study provides reliable baseline data to support integrated waste management strategies emphasising biological treatment, recycling, and improved collection systems in Jos Metropolis.