Sedimentary filters for emerging contaminants in estuarine and coastal systems

A range of increasingly utilised organic chemicals are now found in environmental waters due to their incomplete removal by water treatment processes, or via urban run-off. These include estrogens, personal care products, pharmaceuticals, pesticides, and persistent, so-called "forever chemicals" such as perfluoro-alkylated substances. A number of these emerging organic contaminants are known to have ecosystem and possible human health impacts at very low concentrations, in the parts per billion to parts per trillion range. Although a number of studies have examined the removal, biological uptake or degradation of these contaminants in wastewater or freshwater systems, their interaction mechanisms in and with estuarine systems such as salt marshes (which act as natural filters for many river-supplied contaminants before they enter the sea) are currently unclear. This project will examine the cycling, retention and breakdown of a range of emerging contaminants in estuarine marsh and mudflat systems in two contrasting estuaries - the Solent system on the southern UK coast, and the Pearl River Delta system (China). Work will focus in particular on contaminant degradation or accumulation mechanisms, contaminant interaction with sedimentary organic carbon, and the potential environmental risk that emerging contaminants pose to estuarine and coastal systems.