THE CONTAMINATION OF AGRICULTURAL LAND IN THE METALLIFEROUS PROVINCE OF SOUTHWEST ENGLAND - IMPLICATIONS TO LIVESTOCK

The widespread arsenic and associated metal contamination of soils, attributable to mineralisation and mining activity, in southwest England is reflected to only a limited extent in the composition of washed pasture herbage. However, owing to the limited translocation of both As and Fe to the above-ground portion of the plants, soil contamination can appreciably raise the concentrations of both elements associated with unwashed herbage. The consumption of soil contaminated grass by cattle therefore leads to soil ingestion being a major pathway of both elements to the livestock. Thus, up to 97% of the total dry matter intake of As may be via ingested soil. Reference to a control model indicates that cattle on mine contaminated land may ingest up to 31 times more As than livestock grazing uncontaminated pastures, but the implications of this enhanced intake are not known in detail.