JEP  Vol.4 No.7 , July 2013
Microbial Contamination in Vegetables at the Farm Gate Due to Irrigation with Wastewater in the Tamale Metropolis of Northern Ghana
Abstract: The rational for this study was to assess the microbial quality of fresh vegetables at the farm gate of the Water Works road vegetable farm at Gumbihini in the Tamale Metropolis. A total of thirty-six (36) vegetables comprising lettuce, amarantus and cabbages and eight (8) wastewater samples were collected at random and analysed for a period of four months, to assess the microbial contamination level. Samples were analysed for total coliforms, faecal coliforms, E. coli and helminthes eggs. All vegetables sampled during the study period recorded high levels of total and faecal coliform bacteria. Mean faecal coliforms for the various vegetables were as follows; lettuce 3.7 ± 0.5 CFU.g-1, amarantus 3.5 ± 0.6 CFU.g-1 and cabbage 3.1 ± 0.6 log CFU.g-1 fresh weight. FC levels were above the International Commission on Microbiological Specifications for Foods (ICMSF) recommended level of 3 log CFU.g-1 fresh weight. E. coli were recorded in lettuce (3.3 ± 0.6 log CFU.g-1 fresh weight) and amarantus (0.6 ± 0.1 log CFU.g-1 fresh weight) but not in cabbages. Lettuce generally recorded high levels of microbial contamination because of the large surface area occupied by its leaves. Two helminth eggs (Strongiloides stercoralis) were identified in lettuce while four (Ascaris lumbricoides) were identified in wastewater. Microbial loads recorded in wastewater were generally higher than that of vegetables. Since most of these vegetables are eaten fresh or slightly cooked, there is course for concern as public health will be adversely affected. Education of farmers and consumers on food safety has to be intensified to avert a possible outbreak.

Cite this paper: S. Cobbina, M. Kotochi, J. Korese and M. Akrong, "Microbial Contamination in Vegetables at the Farm Gate Due to Irrigation with Wastewater in the Tamale Metropolis of Northern Ghana," Journal of Environmental Protection, Vol. 4 No. 7, 2013, pp. 676-682. doi: 10.4236/jep.2013.47078.

[1]   C. A. Scott, N. I. Faruqui and L. Raschid-Sally, “Wastewater Use in Irrigated Agriculture: Confronting the Livelihood and Environmental Realities,” CABI, Wallingford, 2004.

[2]   F. Sabiena, H. Raheela and Van der H. Wim, “Health Risks of Irrigation with Untreated Urban Wastewater in the Southern Punjab, Pakistan,” Institute of Public Health (IPH) and International Water Management Institute (IWMI) Research Report No. 107, 2000.

[3]   G. B. Shende and C. Chakrabarti, “Optimum Utilization of Municipal Wastewaters as a Source of Fertilizer,” Journal of Resources and Conservation, Vol. 13, No. 2-4, 1987, pp. 281-290. doi:10.1016/0166-3097(87)90070-8

[4]   Ghana Statistical Services, “2000 Population and Housing Census: Summary Report of Final Results,” Ghana Statistical Services, Legon, Accra, 2002.

[5]   B. Keraita, P. Drechsel, F. Huibers and L. Raschid-Sally, “Watewater Use in Informal Irrigation in Urban and Peri-Urban Areas of Kumasi, Ghana,” Urban Agriculture Magazine, No. 8, 2002, pp. 11-13.

[6]   P. Amoah, P. Drechsel and R. C. Abaidoo, “Irrigated Urban Vegetable Production in Ghana: Sources of Pathogen Contamination and Health Risk Reduction,” Irrigation Drainage, Vol. 54, No. S1, 2005, pp. 49-61. doi:10.1002/ird.185

[7]   R. C. Abaidoo, B. Keraita, P. Amoah, P. Drechsel, J. Bakang, G. Kranjac-Berisavljevic, F. Konradsen, W. Agyekum and A. Klutse, “Safeguarding Public Health Concerns, Livelihoods and Productivity in Wastewater Irrigated Urban and Peri-Urban Vegetable Farming,” CPWF PN 38 Project Report, Kumasi, 2009.

[8]   M. A. S. McMaho and I. G. Wilson, “The Occurrence of Enteric Pathogens and Aeromonas Species in Organic Vegetables,” International Journal of Food Microbiology, Vol. 70, No. 1-2, 2001, pp. 155-162. doi:10.1016/S0168-1605(01)00535-9

[9]   L. R. Beuchat, “Food Safety Issues: Surface Decontamination of Fruits and Vegetables Eaten Raw: A Review,” Food Safety Unit, WHO, Geneva, 1999.

[10]   P. Amoah, P. Drechsel, R. C. Abaidoo and M. Henseler, “Irrigated Urban Vegetable Production in Ghana: Microbiological Contamination in Farms and Markets and Associated Consumer Risk Groups,” Journal for Water and Health, Vol. 5, No. 3, 2007, pp. 455-466. doi:10.2166/wh.2007.041

[11]   D. D. Mara, P. A. Sleigh, U. J. Blumenthaland and R. M. Carr, “Health Risks in Wastewater Irrigation: Comparing Estimates from Quantitative Microbial Risk Analyses and Epidemiological Studies,” Journal of Water and Health, Vol. 5, No. 1, 2007, pp. 39-50. doi:10.2166/wh.2006.055

[12]   J. H. J. Ensink, “Water Quality and the Risk of Hookworm Infection in Pakistani and Indian Sewage Farmers,” PhD Thesis, University of London, London, 2006.

[13]   J. A. Frost, M. B. McEvoy, C. A. Bently, Y. Andersson and B. Rowe, “An Outbreak of Shigella sonnei Infection Associated with Consumption of Iceberg,” Emerging Infectious Disease, Vol. 1, No. 1, 1995, pp. 26-28. doi:10.3201/eid0101.950105

[14]   K. Takeuchi, A. N. Hassan and J. F. Frank, “Penetration of Escherichia coli O157:H7 into Lettuce as Influence by Modified Atmosphere and Temperature,” Journal of Food Protection, Vol. 64, No. 11, 2001, pp. 1820-1823.

[15]   S. Abdul-Ghaniyu, G. Kranjac-Berisavljevic, I. B. Yakubu and B. Keraita, “Sources and Quality of Water Used in Urban Vegetable Production in Tamale Municipality, Ghana,” AU Magazine no.8-Wastewater Reuse in Urban Agriculture, 2005.

[16]   APHA, AWWA, WEF, “Standard Methods for the Examination of Water and Wastewater,” 20th Edition, American Water Works Association, Denver, 1998.

[17]   J. Schwartzbrod, “Methods of Analysis of Helminth Eggs and Cysts in Wastewater, Sludge, Soil and Crops,” University Henry Poincare, Nancy, 1998.

[18]   World Health Organization, “Guidelines for Drinking Water Quality. First Addendum to 3rd Edition, Recommendations,” Vol. 1, 1993, p. 444.

[19]   N. O. B. Ackerson and E. Awuah, “Microbial Risk Assessment of Urban Agricultural Farming: A Case Study on Kwame Nkrumah University of Science and Technology Campus, Kumasi, Ghana,” International Journal of Science and Technology, Vol. 1, No. 3, 2012, pp. 118-125.

[20]   M. A. Halablab, I. H. Sheet and H. M. Holail, “Microbiological Quality of Raw Vegetables Grown in Bekaa Valley, Lebanon,” American Journal of Food Technology, Vol. 6, No. 2, 2011, pp. 129-139. doi:10.3923/ajft.2011.129.139

[21]   L. R. Beuchat, “Ecological Factors Influencing Survival and Growth of Human Pathogens on Raw Fruits and Vegetables,” Microbial Infections, Vol. 4, No. 4, 2002, pp. 413-423. doi:10.1016/S1286-4579(02)01555-1

[22]   J. Spencer, H. R. Smith and H. Chart, “Characterization of Enteroaggregative Escherichia coli Isolated from Outbreaks of Diarrhoeal Disease in England,” Epidemiology and Infection, Vol. 123, No. 3, 1999, pp. 413-421. doi:10.1017/S0950268899002976

[23]   S. M. Faruque, M. J. Albert and J. J. Mekalanos, “Epidemiology, Genetics and Ecology of Toxigenic Vibrio Cholerae,” Microbiology and Molecular Biology Reviews, Vol. 62, No. 4, 1998, pp. 1301-1314.

[24]   P. S. Mead and P. M. Griffin, “Escherichia coli O157:H7,” Lancet, Vol. 352, No. 9135, 1998, pp. 1207-1212. doi:10.1016/S0140-6736(98)01267-7

[25]   H. Michino, K. Araki, S. Minami, et al., “Massive outbreak of Escherichia coli O157:H7 Infection in School Children, Sakai City, Japan, Associated with Consumption of White Radish Sprouts” American Journal Epidemiology, Vol. 150, No. 8, 1999, pp. 787-796. doi:10.1093/oxfordjournals.aje.a010082

[26]   H. I. Shuval, “Health Guidelines and Standards for Wastewater Reuse in Agriculture: Historical Perspectives,” Water Science and Technology, Vol. 23, No. 10-12, 1991, pp. 2037-2080.

[27]   World Health Organization, “Health Guidelines for the Use of Wastewater in Agriculture and Aquaculture,” Technical Report Series No. 778. WHO Scientific Group, Geneva, 1989.

[28]   World Health Organisation, “Guidelines for the Use of Wastewater Excreta and Grey Water: Wastewater Use in Agriculture,” Vol. 1, 2, 4, WHO, Geneva, 2006.