Heavy Metal Contamination in the Bangladeshi Food Chain and Associated Human Health Risks: A Systematic Review with government implications

Background Heavy metal contamination in foodstuffs poses a significant public health concern in Bangladesh, where rapid industrialisation, urban expansion, and intensive agricultural practices have degraded soil and water quality. Although numerous studies have reported contamination levels in individual food items, a consolidated synthesis of evidence on food-chain exposure and associated health risks remains necessary to inform risk assessment and policy discussion. Objectives This systematic review aimed to synthesize published evidence on the prevalence of heavy metals in the Bangladeshi food chain and the associated human health risks, and to identify key gaps in the existing evidence base. Methods A systematic literature search was conducted across major scientific databases and relevant grey literature sources for studies published between 2000 and 2025. Eligible studies reporting heavy metal concentrations in food items and associated health risk indicators in Bangladesh were screened and included according to predefined criteria. Data were extracted on food type, metal species, concentration ranges, and reported health risk metrics, and were synthesized narratively due to heterogeneity in study designs and outcome measures. Results The reviewed studies consistently reported elevated concentrations of toxic metals—particularly arsenic (As), cadmium (Cd), lead (Pb), and chromium (Cr)—in commonly consumed foods, including rice, vegetables, fish, dairy products, and meat, frequently exceeding international safety thresholds. Dietary exposure to these metals was associated with increased non-carcinogenic and carcinogenic health risks, including neurotoxicity, renal dysfunction, cardiovascular effects, and cancer risk. Considerable variability across food groups, geographic locations, and study methodologies was observed. Conclusions The synthesized evidence indicates that dietary exposure to heavy metals represents a substantial public health risk in Bangladesh. The findings also highlight persistent gaps in regulatory evaluation, monitoring capacity, and policy integration, suggesting the need for adaptive governance approaches to complement existing food safety and environmental management strategies.