ABSTRACT:
Flooding can increase the mobilisation of hazardous chemicals in the environment and adversely affect human health. Climate change is already increasing heavy rainfall and flooding events, and the increased exposure to hazardous chemicals requires greater policy and research input. This scoping review provides an overview of current evidence on how flood events cause chemical contamination, population exposures and impacts on health. Exposures to hazardous chemicals can be caused by surface water flooding, coastal flooding, river flooding, storm surge, monsoon rainfall and high tides. We identified 108 studies examining the association between flooding and chemicals in the environment, with most focusing on heavy metals, polycyclic aromatic hydrocarbons, and arsenic. Over half of the papers reviewed investigated the aftermath of Hurricanes. There was a lack of information on rural population exposures and studies on mobilisation of pesticides. Limited studies mapped or modelled human exposures, including for high-risk populations (e.g., children, pregnant women), and this remains a critical evidence gap. Our results highlighted several pathways by which flood events can mobilise chemicals and pose risks to human health. A dual risk management strategy (i.e., the coordinated management of both flood-related and chemical release risks) is required to address flooding events, chemical releases, and health impacts.