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Cornwall has numerous derelict Cu-Sn mine sites scattered throughout the county-a legacy of past intensive mining activity. Due to the toxic concentrations of heavy metals many sites are poorly vegetated which leads to continued dispersion of toxic metals into the surrounding farming environment. The aim of this research is to establish the extent of contamination, to determine its form, and to ascertain how much dispersion is currently occurring. A case study of the Tresavean Mine near Redruth, west Cornwall, UK, has shown that the distribution of As and Cu from the mine extends up to 150 m. An extensive soil survey of the farmland surrounding the mine revealed two distinct distribution patterns for As and Cu. Arsenic distribution appears to correlate with the prevailing wind direction at the site, whereas the Cu distribution follows the down slope drainage pattern. Sequential extractions were made on soil samples taken at intervals along a transect from the mine to determine which soil fractions Cu and As are held in; i.e. water-soluble, exchangeable, adsorbed, organic, Fe-Mn oxides or residual. These sequential extractions indicate the Cu is held mainly in the residual and organic fractions and As is held mainly in the residual and iron-organic fractions. Although the absolute concentrations of As and Cu decrease with distance from the mine site, as expected, the percentage of As and Cu in each fraction does not follow this pattern in every case.

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