Assessing the impact of historic mining on the geochemistry of sediments in the Camel Estuary, Cornwall, U.K.

This investigation focusses on the geochemical properties of surficial sediments in the Camel Estuary, Cornwall, UK. The
geochemistry of the samples were determined by XRF and data for Sn, As, Cu, Pb and Zn are presented. The data for Pb, Zn and
As shows a down estuary reduction, probably resulting from a combination of increasing distance from a presumed metalliferous
mining source and mixing with marine sediments. The highest concentrations for As (48 ppm) and Zn (304 ppm) exceed
sediment quality guidelines. Cu and Pb values are below the sediment quality guidelines. Although elevated Sn concentrations are
seen in the middle part of the estuary, given that the Sn is likely to be associated predominantly with cassiterite, it is less likely
to be bioavailable. These pollutants have persisted long after the mining activity of the nineteenth century ceased. Compared to
other estuaries in the southwest, the Camel Estuary is relatively unpolluted.