Environmental Health Impacts Due to Solid Waste Disposal of Dhaka City in Bangladesh

This study evaluated the environmental impacts of the Matuail landfill by analyzing heavy metal concentrations in soil, leachate, ambient air, and commonly consumed vegetables collected from the dumping area, abandoned landfill area, and surrounding agricultural areas using standard analytical methods. The existing leachate treatment system, which employs chemical coagulation (ferrous sulphate, lime, and polymer) followed by a semi-aerobic biological pond, was evaluated for treatment efficiency. Soils from the active dumping area contained significantly (P<0.001) higher heavy metal concentrations, including Zn (1537±118.98 mg/kg), Cu (359.5±20.62 mg/kg), Pb (221±15.75 mg/kg), and Ni (174.25±6.90 mg/kg), far exceeding national and international permissible limits. The abandoned landfill area and surrounding agricultural areas showed progressively lower contamination. Untreated leachate exhibited high levels of Fe (22.45±1.74 mg/L), chemical oxygen demand (1428.25±94.55 mg/L), and Ni (4.43±0.10 mg/L), while treated leachate still retained elevated total dissolved solids (3546.75±60.62 mg/L) and chemical oxygen demand (437.75±30.09 mg/L), with removal efficiencies of only 72.7% for COD and 45.1% for Ni, indicating incomplete purification. Air quality was severely degraded, with suspended particulate matter (330.75±17.91 μg/m 3 ), PM2.5 (113.5±7.72 μg/m 3 ), SO 2 (597.5±14.27 μg/m 3 ), and NOX (204±4.97 μg/m 3 surpassing national standards. Vegetables grown nearby accumulated hazardous metals, particularly Pb (up to 134.3 μg/g) and Ni (up to 118 μg/g), far above safe limits. Multivariate visual analyses (heatmaps, radar plots) consistently highlighted the landfill and its surroundings as contamination hotspots. This assessment demonstrates significant environmental and public health hazards associated with the Matuail landfill in Dhaka, Bangladesh. Importantly, the findings have practical implications, as they can inform stricter emission controls, upgraded leachate treatment (Fenton oxidation, biochar adsorption), targeted crop monitoring, and hotspot-based mitigation strategies. By linking quantitative evidence with actionable insights, this study provides a framework for policymakers, waste management authorities, and public health experts to minimize risks and advance sustainable landfill practices.