 The majority of sediment cores show a clear decrease in Hg concentrations close to the surface which is attributed to an overall reduction in polluting activities as well as improved effectiveness of recent environmental legalisation and river management (e.g.Oslo-Paris convention).Evaluation of select of lipid compounds in the Thames estuary, known as glycerol dialkyl glycerol tetraethers (GDGTs) has revealed enhanced concentrations of isoprenoid GDGT compounds (crenarchaeol) around East London.