Integrated pollution regimes and water resource sustainability across Bangladeshi rivers and aquifers

Water pollution has emerged as a critical challenge to water resource sustainability in Bangladesh due to rapid industrialization, urban expansion, agricultural intensification, and inadequate wastewater management. Despite numerous localized investigations, an integrated national-scale assessment linking pollution behavior, environmental risk, and sustainability implications across aquatic systems remains limited. This study presents a comprehensive multi-decadal synthesis (2000–2026) of water pollution conditions across Bangladeshi rivers and aquifers through comprehensive compilation and comparative evaluation of physicochemical parameters, heavy metals, sediment contamination, and microbial indicators from peer-reviewed and regionally relevant environmental monitoring studies. The synthesis reveals substantial spatial variability in pollution intensity across aquatic systems. Urban-industrial rivers, particularly within major metropolitan and industrial corridors, exhibit severe organic contamination, elevated biochemical and chemical oxygen demand, critically low dissolved oxygen concentrations, and significant heavy metal enrichment. Large river systems demonstrate partial dilution capacity but substantial sediment-associated contaminant accumulation, while rural and agricultural systems show increasing nutrient and microbial pollution. Groundwater systems are predominantly affected by geogenic contamination, especially arsenic mobilization within alluvial aquifers. An original Comparative Pollution Regime Framework was developed to translate heterogeneous multi-compartment environmental observations into reproducible regime-level interpretation using benchmark-normalized severity, documented source attribution, temporal/spatial recurrence, independent corroborating evidence, and explicit evidence-confidence criteria. The findings further establish critical relationships between pollution sources, transport pathways, sediment accumulation, seasonal hydrological variability, and human exposure risks. The study highlights the importance of integrated monitoring systems, industrial effluent control, sediment management, and adaptive water governance for improving long-term water resource sustainability in Bangladesh.