Usage of Untreated Sewage Effluent for Irrigation and its Impact on Vegetables Quality
City effluent from Pakistans third largest city (Faisalabad) is used as supplementary irrigation water to produce vegetables for human consumption. This paper reports a study to commence the assessment of risks and opportunities associated with this practice, with emphasis on cadmium (Cd), which is a toxic heavy metal that can enter the food chain as an impurity in vegetables. Cadmium and other properties were measured in typical effluents, four soils and a range of vegetables in the absence of fertilizer additions. It was found that the city effluent increased soil salinity, sodicity and cadmium concentrations. The Cd concentrations in the vegetables were also above those normally associated with suitability for human consumption. There were suggestions that soluble Cd concentrations in the effluent could be lessened by the addition of lime, concurrently lowering the sodium adsorption ratio of the effluent.
Ahmad,N., Ibrahim,M. and A. Khan (1994). Sewage effluent for raising vegetables. 4th National Congr. Soil Sci. 24-26 May, 1992, Islamabad, Pakistan, pp. 593-597.
AOAC (1984). Official methods of analysis of the Association of Official Analytical Chemists. AOAC Inc., Virginia, USA.
Ayres, R.S. and D.W. Westcot (1985). Water quality for Agriculture. FAO Irri. and Drain. Paper 29: 95-97.
Benoff, S., Jacob,A. and I.R. Hurley(2000). Male infertility and environmental exposure to lead and cadmium. Hum. Reprod. Update 2000; 6: 107-121.
Brady, N.C. (1996). The nature and properties of soil, 10th Ed., Macmillan Publishing Company, New York, USA.
Friberg Lars, M.D. (2000). Perspectives on cadmium health effects. Environmental cadmium in the food chain: sources, pathways and risks. Proceedings of the SCOPE workshop, Belgian academy of science, Brussels, Belgium, 13-16 September 2000,pp. 7-13.
Ghafoor, A., Rauf, A., Arif, M. and W. Muzaffar (1994). Chemical composition of effluents from different industries of the Faisalabad city. Pak. J. Agyic. Sci., 31: 367-369.
Gochfeld, M. (2000) . Cadmium: Application of a risk approach. Environmental cadmium in the food chain: Sources, pathways and risks. Proceedings of the SCOPE workshop,Belgian academy of science, Brussels, Belgium, 13-16 September 2000,pp. 14-19.
Khan, A., Ibrahim, M., Ahmed, N. and S.A. Anwar (1994). Accumulation of heavy metals in soil receiving sewage effluent. J. Agyi. Res., 32: 525-533.
Kido, T., Nogawa, K., Yamada, Y., Honda, R., Tsuritani, I., Ishizaki, M. and Yamaya, H. (1989) . Osteopenia in inhabitants with renal dysfunction induced by exposure to environmental cadmium. Int.Aych. Occup. Enviyon. Health, 61: 271-276.
Nabi, G., Arshad, M. and M.R. Aslam (2001). Heavy metal contamination of agriculture soils irrigated with industrial effluents. Sci. Tech. and Development, 20: 32-36.
Nazir, S. (1994). Crop Production. National Book Foundation Samar Printer,s, Karachi. Pakistan.
Nogawa, K., Tsuritani, I., Kido, Honda, R., Yamada, Y. and M. Ishizaki (1987). Mechanism for bone disease found in inhabitants environmentally exposed to cadmium: Decreased serum 1 alpha, 25-dihydroxyvitamin D level. Int. Aych. Occup. Enviyon. Health, 59: 21-30.
Rashid,A.and K.S. Memon (1996). Soil Science: Soil Salinity, Sodicity and Water Logging. National Book Foundation. Islamabad. Pakistan, pp. 471-508.
Rattan,B.K., Datta, S.P., Suresh Chandra and Neelam Saharan (2002). Heavy metals and environmental quality. Feytilizey News. India, 47(11): 29-40.
Richard,J. Lewis, Sr.(1998). Condensed Chemical Dictionary. Thirteenth Edition. Galgotia Publication Pvt. Ltd., New Delhi, India, 189 pp.
Rowell, R.B. (1994). Soil Science: Method and applications. Pesticides and metals. pp. 303-327. Longman Singapore Publisher (Pte) Ltd., Singapore.
Satarug, S., Haswell-Elkins, M.R. and M.R. Moore (2000). Safe levels of cadmium intake to prevent renal toxicity in human subjects. By. J. Nuty., 84: 791-802.
Smolders, E. (2000). Cadmium availability in soils and identification of high risk soils. Environmental cadmium in the food chain: sources, pathways and risks. Proceedings of the SCOPE workshop, Belgian academy of science, Brussels, Belgium, 13-16 September 2000,pp. 71-75.
US Salinity Lab. Staff (1954). Diagnosis and improvement of saline and alkali soils. USDA Handbook No. 60, Washington, D.C.
WHO (World Health Organization) (1996). Guidelines for drinking-water quality. Health Criteria and other supporting information. 94/9960-Mastercom/wiener verlag-800, Australia.