This study will aim to establish the fate of potentially toxic elements (PTEs) consumed by livestock that graze on sludged land. Accumulation of PTEs (e.g. Cd, Pb, Cu, Zn and Fe) in the body tissues of weaned lambs grazing on pasture treated with sewage sludge (up to statutory limits of Cd and/or Pb) will be examined. If possible, untreated land adjacent to treated land will be grazed simultaneously by a separate, similar group of animals. Rate of PTE uptake into body tissues will then be determined by serial slaughter. Sward height, stocking rate, weather conditions, and soil and herbage concentrations will also be monitored. The project will also evaluate effect of season (autumn or spring) and method of application (e.g. surface spreading or injection into soil) on ingestion of soil, herbage and sewage sludge, together with accumulation of PTEs, by weaned lambs grazing pastures treated with normal operational amounts (approx. 50m3/ha) of sewage sludge. A previously developed model examining the soil/grass/animal chain of accumulation of PTEs in body tissues will be further developed in this study. Furthermore, margins of safety will be identified with respect to limits for levels of PTEs in soils used for grassland, stipulated by Statutory Instrument No. 1263 and the Department of Environment Code of Practice.