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Accumulation of potentially toxic elements in the body tissues of sheep grazed on grassland given repeated applications of sewage sludge

Published online by Cambridge University Press:  18 August 2016

J.M. Wilkinson
Affiliation:
School of Biology, University of Leeds, Leeds LS2 9JT, UK
J. Hill
Affiliation:
Department of Agriculture and Rural Management, University College Writtle, Chelmsford, CM1 3RR, UK
C.T. Livesey
Affiliation:
Veterinary Laboratory Agencies, New Haw, Addlestone KT15 3NB, UK
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Abstract

Ingestion of sewage sludge with soil, together with herbage containing elevated concentrations of potentially toxic elements (PTEs) might pose a risk to the human food chain through the accumulation of PTEs in edible tissues of livestock grazed on pastures which have received repeated doses of sludge. The accumulation of PTEs in tissues of animals grazed on a permanent pasture which had received repeated applications of sewage sludge between 1981 and 1994 was studied over two consecutive grazing seasons by monthly serial slaughter. Blocks of six weaned lambs were allocated at random at the start of the grazing seasons to slaughter date. Blocks of lambs were also allocated at random to an adjacent untreated pasture and to initial slaughter groups. Animals grazed continuously for two periods of 181 days and 152 days in 1994 (experiment 1) and 1995 (experiment 2), respectively. An application of sewage sludge was made to the treated site between the two experiments. The concentration of cadmium (Cd) in soil samples taken to 25 cm depth from the treated site was close to the United Kingdom statutory limit of 3 mg Cd per kg dry matter (DM) and 1·67 times the limit at the soil surface. Concentrations of other PTEs in soil were below statutory limis. The concentrations of PTEs in herbage at the treated site increased as each grazing period advanced (P < 0·05). Mean concentrations of Cd, lead (Pb), copper (Cu) and zinc (Zn) were higher (P < 0·05) in both experiments for herbage at the treated site than at the untreated site. No differences were observed in the concentrations of PTEs in muscle tissue between lambs grazed on treated or untreated pastures. The concentration of Cd in kidneys of lambs grazed on the treated pasture increased as the grazing seasons progressed from 0·19 to 0·36 mg/kg DM (P < 0·01) in experiment 1 and from 0·03 to 2·57 mg/kg DM in experiment 2 (P < 0·001). There was no measurable accumulation of Pb into kidney in either experiment. Concentrations of Cu in kidney remained similar during experiment 1 but increased during experiment 2 in lambs grazed on the treated pasture only (P < 0·05). Similar trends to those for kidney were observed for Cd in liver in both experiments. The concentrations of Pb increased in liver for lambs grazed on the treated site in experiment 1 (P < 0·01) but not in experiment 2. The concentrations of Cu in lambs grazed on the treated pasture in liver decreased (P < 0·01) in experiment 1 from 139 to 28 mg Cu per kg DM. Liver concentrations of Cu in experiment 2 increased (P < 0·01) from 63·5 to 197 mg Cu per kg DM, possibly reflecting the application of sludge to the experimental site between the two experiments. The results indicated that soil and herbage concentrations of PTEs were elevated following repeated applications of sewage sludge to grassland. The accumulation of PTEs in edible body tissues was generally low, with the greatest being of Cd and Cu in the second experiment, possibly reflecting recent application of sludge.

Type
Ruminant nutrition, behaviour and production
Copyright
Copyright © British Society of Animal Science 2001

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References

Aitken, M. 1997. Short-term leaf surface adhesion of heavy metals following application of sewage sludge to grassland. Grass and Forage Science 52: 7385.CrossRefGoogle Scholar
Carrington, E.G., Davies, R.D., Hall, J.E., Pike, E.B., Smith, S.R. and Unwin, R.J. 1998. Review of the scientific evidence relating to the controls in agricultural use of sewage sludge. Part 2. Evidence since 1989 relevant to controls on the agricultural use of sewage sludge. Final report to Department of the Environment, Transport and the Regions, Department of Health, Ministry of Agriculture, Fisheries and Food and UK Water Industry Research Ltd, report no. 4454/4. WRc plc publications, Medmenham.Google Scholar
Council of the European Communities. 1986. Council directive of 12 June 1986 on the pollution of the environment and in particular of the soil, when sewage sludge is used in agriculture. Directive 86/278/EEC. Official Journal of the European Communities no. L181, pp. 612.Google Scholar
Council of the European Communities. 1991. Urban Waste Water Treatment Directive. Directive 91/271/EEC, Official Journal of the European Communities no. L135, pp. 4052.Google Scholar
Davies, R.D., Carlton-Smith, C.H., Stark, J.H. and Campbell, J.A. 1988. Distribution of metals in grassland soils following surface applications of sewage sludge. Environmental Pollution 49: 99115.Google Scholar
Dewes, H.F. 1986. The rate of soil ingestion by dairy cows and the effect on availabilities of Cu, Ca, Na and Mg. New Zealand Veterinary Journal 44: 199200.Google Scholar
Ferguson, C.C. 1996. Assessing human health risks from exposure to contaminated land: a review of recent research. Land Contamination and Reclamation 4: 159170.Google Scholar
Fox, M.R. 1986. Nutritional factors that may influence bioavailability of cadmium. Journal of Environmental Quality 17: 175188.Google Scholar
Grace, N.D., Rounce, J.R. and Lee, J. 1993. Intake and excretion of cadmium in sheep fed fresh herbage. Proceedings of the New Zealand Society of Animal Production 53: 251253.Google Scholar
Great Britain Parliament. 1989. The sludge (use in agriculture) regulations, 1989. Statutory Instruments 1989 no. 1263. Her Majesty’s Stationery Office, London.Google Scholar
Healy, W.B. 1967. Ingestion of soil by sheep. Proceedings of the New Zealand Society of Animal Production 27: 109120.Google Scholar
Hill, J., Stark, B.A., Wilkinson, J.M., Curran, M.K., Lean, I.J., Hall, J.E. and Livesey, C.T. 1998a. Accumulation of potentially toxic elements by sheep given diets containing soil and sewage sludge. 1. Effect of type of soil and level of sewage sludge in the diet. Animal Science 67: 7386.CrossRefGoogle Scholar
Hill, J., Stark, B.A., Wilkinson, J.M., Curran, M.K., Lean, I.J., Hall, J.E. and Livesey, C.T. 1998b. Accumulation of potentially toxic elements by sheep given diets containing soil and sewage sludge. 2. Effect of the ingestion of soils treated historically with sewage sludge. Animal Science 67: 8796.CrossRefGoogle Scholar
Jarvis, M.G., Allen, R.H., Fordham, S.J., Hazelden, J., Moffat, A.J. and Sturdy, R.G. 1984. Soils and their use in South East England. Soil Survey of England and Wales, bulletin no. 15, Harpenden, UK.Google Scholar
Lamy, I., Bourgeois, S. and Bermond, A. 1993. Soil cadmium mobility as a consequence of sewage sludge disposal. Journal of Environmental Quality 22: 731737.CrossRefGoogle Scholar
Lawes Agricultural Trust. 1990. GENSTAT V, release 2·2. Rothamsted Experimental Station, Harpenden, Hertfordshire.Google Scholar
Lee, J., Grace, N.D. and Rounce, J.R. 1994a. Cadmium accumulation in liver and kidney of sheep grazing ryegrass/white clover pastures. Proceedings of the New Zealand Society of Animal Production 54: 3134.Google Scholar
Lee, J., Treloar, B.P. and Grace, N.D. 1994b. Metallothionein and trace element metabolism in sheep tissues in response to high and sustained Zn dosages. II. Expression of metallothionein m-RNA. Australian Journal of Agricultural Research 45: 321332.Google Scholar
McGrath, D., Poole, D.B.R., Fleming, G.A. and Sinnott, J. 1982. Soil ingestion by grazing sheep. Irish Journal of Agricultural Research 21: 135145.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1986. The analysis of agricultural materials. Her Majesty’s Stationery Office, London.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1993. Review of the rules for sewage sludge application to agricultural land. Soil fertility aspects of potentially toxic elements. Report of the Independent Scientific Committee. MAFF Publications, London.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1997a. 1994 Total diet survey: metals and other elements. Food Surveillance Information Sheet no. 131. MAFF Publications, London.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1997b. Survey of lead and cadmium in foods. Food Surveillance Information Sheet no. 113. MAFF Publications, London.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1998. Lead, cadmium, copper and zinc in offals. Food Surveillance Information Sheet no. 160. MAFF Publications, London.Google Scholar
National Research Council. 1980. Mineral tolerance for domestic animals. National Academy Press, Washington, USA.Google Scholar
Petering, D.H. and Fowler, B.A. 1986. Discussion summary. Roles of metallothionein and related proteins in metabolism and toxicity: problems and perspectives. Environmental Health Perspectives 65: 217224.Google Scholar
Smith, S.R. 1996. Agricultural recycling of sewage sludge and the environment. CAB International, Wallingford, UK.Google Scholar
Stark, B.A. 1988. Effects on grazing animals of ingestion of inorganic and organic materials contained in sewage sludge. Report PRU 1691-M, Water Research Centre, Medmenham, UK.Google Scholar
Taylor, W. and Leaver, J.D. 1984. Systems of concentrate allocation for dairy cattle. 1. A comparison of three patterns of allocation for autumn-calving cows and heifers offered grass silage ad libitum . Animal Production 39: 315324.Google Scholar