The impact of floods on plastic pollution

Reducing plastic pollution requires a thorough understanding of its sources, sinks, abundance, and impact. The transport and retention dynamics of plastics are however complex, and assumed to be driven by natural factors, anthropogenic factors, and plastic item characteristics. Current literature shows diverging correlations between river discharge, wind speed, rainfall, and plastic transport. However, floods have been consistently demonstrated to impact plastic transport and dispersal. Here, we present a synthesis of the impact of floods on plastic pollution in the environment. For each specific flood type (fluvial, pluvial, coastal and flash floods), we identified the driving transport mechanisms from the available literature. We introduce the plastic-flood nexus concept, which is the negative feedback loop between floods (mobilizing plastics), and plastic pollution (increasing flood risk through blockages). Moreover, we assessed the impact of flood-driven plastic transport, and argue that increasing flood resilience also reduces the impact of floods on plastic pollution. In this paper we provide a perspective on the importance of floods on global plastic pollution. We argue that increasing flood resilience, and breaking the plastic-flood nexus, are crucial steps towards reducing environmental plastic pollution.