Heavy metals in the Humber estuary: Scrobicularia clay as a pre-industrial datum

Abstract
SUMMARY: A series of twenty-one samples of recently deposited sediments have been collected from both shores of the Humber estuary and analysed for a range of major and trace elements. Four samples of ‘prehistoric’ Scrobicularia clay from Easington have been processed and examined in the same manner to provide a base-line datum for the estuary before the anthropogenic addition of inorganic pollutants. Many elements can be seen to be enriched in modern sediments compared to their prehistoric counterpart. Elements such as Fe, Ti, Nb and As can be directly linked to present-day industrial discharges. Other elements, including P, Pb, Zn, Cu, Cr and V, show varying degrees of enrichment but are probably being introduced from several sources. Mn concentration seems to be controlled largely by water salinity. The overall impression gained is that of a well mixed estuary with some local ‘hot-spots’.