In flux: Annual transport and deposition of suspended heavy metals and trace elements in the urbanised, tropical Red River Delta, Vietnam

•First calculations of suspended metal pollution for the red river Delta, vietnam.•The global flux contribution is <0.2% and not a major source of oceanic pollution.•The delta is largely a sink of pollutants with a high level of deposition (∼50%).•‘Hotspots’ of pollution due to dissolved organic matter, monsoons, and salinity.•Predicted increases in severe storms, saline intrusion and human activity can shift sink to source.