Plastic pollution in the Ganga River: Modeling the town-level impact of population and waste management systems using...

Plastic pollution in riverine environments poses a growing threat to ecosystems and human well-being, with the Ganga River emerging as a critical hotspot. This study introduces a novel town-level modeling framework that integrates population dynamics and heterogeneity in waste generation and management factors including collection, treatment, and recycling efficiencies, in the Ganga River basin to estimate riverine plastic waste (RPW). Model predictions were validated using the field data showing waste generation estimates within ±10 %. Riverine plastic waste values also aligned well with published literature, with model outcomes lying within ±1.4 z-scores. Results indicate that under the business-as-usual (BAU) scenario, mismanaged plastic waste (MMPW) is projected to range between 550 and 750 kt/yr by 2061. Implementation of the improved-waste-management (IWM) scenario reduces this by 81 %, lowering MMPW to 40-140 kt/yr. Correspondingly, RPW from the Ganga River declines by 75 %, from 250 kt/yr (BAU) to 60 kt/yr (IWM), for 2061. Sensitivity analysis indicates that key drivers of riverine plastic waste shift over time, from plastic waste generation rates in early years to waste management efficiency in later decades. By accounting for India's evolving lifestyle and increasing plastic use, this study bridges the gap between global-scale assessments and localized inputs, providing actionable insights to guide policy, accelerate mitigation, and advance sustainable waste management in developing economies.