Your search found 13 records
1 Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa. (Eds.) 2010. Wastewater irrigation and health: assessing and mitigating risk in low-income countries. Colombo, Sri Lanka: International Water Management Institute (IWMI); London, UK: Earthscan; Ottawa, Canada: International Development Research Centre (IDRC). 404p.
Wastewater irrigation ; Public health ; Health hazards ; Risk assessment ; Epidemiology ; Sewage sludge ; Excreta ; Diseases ; Vegetables ; Leaf vegetables ; Economic impact ; Wastewater treatment ; Irrigation methods ; Developing countries
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE Record No: H042600)
(5.45 MB)
In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw. Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater. This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.
2 Seidu, R.; Drechsel, Pay. 2010. Cost-effectiveness analysis of interventions for diarrhoeal disease reduction among consumers of wastewater-irrigated lettuce in Ghana. In Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa (Eds.). Wastewater irrigation and health: assessing and mitigating risk in low-income countries. London, UK: Earthscan; Ottawa, Canada: International Development Research Centre (IDRC); Colombo, Sri Lanka: International Water Management Institute (IWMI). pp.261-283. (Also in French).
Wastewater irrigation ; Lettuces ; Leaf vegetables ; Diseases ; Diarrhoea ; Health hazards ; Risk assessment / Ghana
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE Record No: H042613)
(0.27 MB)
Interventions proposed and implemented for the mitigation of diarrhoeal diseases associated with wastewater reuse in agriculture have received little, if any, comparative assessment of their cost-effectiveness. This chapter assesses the costs, outcomes and cost-effectiveness of the so-called ‘treatment’ and ‘non- or post-treatment’ interventions as well as a combination of these for wastewater irrigation in urban Ghana using an approach that integrates quantitative microbial risk assessment (QMRA), disability-adjusted life years (DALYs) and cost-effectiveness analysis (CEA). The cost-effectiveness ratios (CERs) for the treatment and non-treatment interventions assessed ranged from US$31/DALY to US$812/DALY averted. Risk-reduction measures targeting farming practices and the basic rehabilitation of local wastewater treatment plants were the most attractive interventions with a CER well below the threshold of US$150/DALY, sometimes considered as the upper limit for a health intervention to be cost-effective in developing countries. All combinations associated with the basic rehabilitation of the treatment plants, with either on-farm or post-harvest interventions or both, resulted in CERs within the range of US$40/DALY to US$57/DALY. However, the CERs for the construction of a new wastewater treatment plant either as an independent intervention or in combination with on-farm and post-harvest interventions were unattractive in view of health-risk reduction for wastewater irrigation. Although attractive, the CERs of non-treatment options are largely dependent on compliance (adoption) by farmers and food vendors. In this regard, the CER increased by almost fivefold when the adoption rate was only 25 per cent by farmers and food vendors; but was attractive as long as adoption rates did not fall below 70 per cent. On the other hand, the success of the treatment option depends on the functionality of the treatment plants which is not without challenges in a country like Ghana. Thus, this chapter stresses the need for a balanced risk-management approach through a combination of treatment and non-treatment interventions to hedge against failures that may affect CERs at any end. While this chapter provides a contribution to the debate on interventions for health-risk mitigation in wastewater irrigation, more case studies would be useful to verify the data presented here.
3 Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa. (Eds.) 2010. Wastewater irrigation and health: assessing and mitigating risk in low-income countries. London, UK: Earthscan; Ottawa, Canada: International Development Research Centre (IDRC); Colombo, Sri Lanka: International Water Management Institute (IWMI). 404p.
Wastewater irrigation ; Public health ; Health hazards ; Risk assessment ; Epidemiology ; Sewage sludge ; Excreta ; Diseases ; Vegetables ; Leaf vegetables ; Economic impact ; Wastewater treatment ; Irrigation methods ; Developing countries
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE c2 Record No: H042759)
In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw. Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater. This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.
4 Holm, P. E.; Marcussen, H.; Dalsgaard, A. 2010. Fate and risks of potentially toxic elements in wastewater-fed food production systems: the examples of Cambodia and Vietnam. Irrigation and Drainage Systems, 24(1-2):127-142 (Special issue with contributions by IWMI authors) [doi: https://doi.org/10.1007/s10795-009-9086-6]
Wastewater irrigation ; Water quality ; Heavy metals ; Sedimentary materials ; Food production ; Risks ; Fish ; Leaf vegetables ; Health hazards ; Farmers ; Urban areas / South East Asia / Cambodia / Vietnam / Hanoi / Phnom Penh
(Location: IWMI HQ Call no: e-copy only Record No: H042883)
http://www.springerlink.com/content/762895738805724j/fulltext.pdf
https://vlibrary.iwmi.org/pdf/H042883.pdf
https://vlibrary.iwmi.org/pdf/H042883.pdf
(0.20 MB)
Non-treated wastewater is used for irrigation of aquatic food production systems in the peri-urban areas of the major cities in Southeast Asia. This paper complement the knowledge on agricultural soil-based crops irrigated with low quality water, by reviewing the research findings on the wastewater-fed aquatic productions with special focus on heavy metals and other potentially toxic elements (PTEs) in the production systems of Hanoi in Vietnam and Phnom Penh in Cambodia. In Hanoi, sediments in the wastewater exposed rivers of Hanoi were reported to be polluted with PTEs, in particular with Cadmium (Cd). The river sediment had a high retention capacity for PTEs which seems to prevent the transport of PTEs to the wastewater-fed production systems. In Phnom Penh, domestic and industrial wastewater is pumped into the Cheung Ek Lake located south of the city. A major part of the water spinach (Ipomoea aquatica Forssk.) consumed in the city is produced in the lake. The concentrations of some PTEs were elevated at the wastewater inlets to the lake compared to concentrations at the lake outlet and at the control site. Water spinach is by far the major vegetable produced in the wastewater-fed systems in Hanoi and Phnom Penh, but did only contain PTEs in concentrations within or slightly above the concentration range observed for water spinach grown in agricultural soil not exposed to wastewater. PTE concentration in fish grown in wastewater-fed systems in Hanoi and Phnom were low. However, mean PTE concentrations in liver and skin of some fish were high. Consumption of muscle tissue from fish produced in wastewater-fed systems in Hanoi and Phnom Penh resulted in an estimated intake of PTEs amounting to less than 9% of the tolerable intake. It was concluded, that the PTE concentrations in fish and water spinach from Hanoi and Cheung Ek Lake in Phnom Penh constituted low food safety risks for consumers.
5 Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa. 2011. L’irrigation avec des eaux usees et la sante: evaluer et attenuer les risques dans les pays a faible revenu. In French. [Wastewater irrigation and health: assessing and mitigating risk in low-income countries]. Colombo, Sri Lanka: International Water Management Institute (IWMI); Ottawa, Canada: International Development Research Centre (IDRC); Quebec, Canada: University of Quebec. 440p. (Also in English).
Wastewater irrigation ; Public health ; Health hazards ; Risk assessment ; Epidemiology ; Sewage sludge ; Excreta ; Diseases ; Vegetables ; Leaf vegetables ; Economic impact ; Wastewater treatment ; Irrigation methods ; Developing countries
(Location: IWMI HQ Call no: IWMI Record No: H044457)
http://www.iwmi.cgiar.org/Research_Impacts/Research_Themes/Theme_3/PDF/French%20book.pdf
https://vlibrary.iwmi.org/pdf/H044457.pdf
https://vlibrary.iwmi.org/pdf/H044457.pdf
(5.96 MB) (5.96MB)
In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw. Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater. This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.
6 Seidu, R.; Drechsel, Pay. 2011. Analyse cout-efficacite des interventions pour reduire les maladies diarrheiques chez les consommateurs de laitues irriguees avec des eaux usees au Ghana. In French. [Cost-effectiveness analysis of interventions for diarrhoeal disease reduction among consumers of wastewater-irrigated lettuce in Ghana]. In Drechsel, Pay; Scott, C. A.; Raschid-Sally, Liqa; Redwood, M.; Bahri, Akissa. L’irrigation avec des eaux usees et la sante: evaluer et attenuer les risques dans les pays a faible revenu. Colombo, Sri Lanka: International Water Management Institute (IWMI); Ottawa, Canada: International Development Research Centre (IDRC); Quebec, Canada: University of Quebec. pp.281-305. (Also in English).
Wastewater irrigation ; Lettuces ; Leaf vegetables ; Diseases ; Diarrhoea ; Health hazards ; Risk assessment / Ghana
(Location: IWMI HQ Call no: IWMI Record No: H044470)
http://www.iwmi.cgiar.org/Research_Impacts/Research_Themes/Theme_3/PDF/French%20book.pdf
https://vlibrary.iwmi.org/pdf/H044470.pdf
https://vlibrary.iwmi.org/pdf/H044470.pdf
(0.95 MB) (5.96MB)
Interventions proposed and implemented for the mitigation of diarrhoeal diseases associated with wastewater reuse in agriculture have received little, if any, comparative assessment of their cost-effectiveness. This chapter assesses the costs, outcomes and cost-effectiveness of the so-called ‘treatment’ and ‘non- or post-treatment’ interventions as well as a combination of these for wastewater irrigation in urban Ghana using an approach that integrates quantitative microbial risk assessment (QMRA), disability-adjusted life years (DALYs) and cost-effectiveness analysis (CEA). The cost-effectiveness ratios (CERs) for the treatment and non-treatment interventions assessed ranged from US$31/DALY to US$812/DALY averted. Risk-reduction measures targeting farming practices and the basic rehabilitation of local wastewater treatment plants were the most attractive interventions with a CER well below the threshold of US$150/DALY, sometimes considered as the upper limit for a health intervention to be cost-effective in developing countries. All combinations associated with the basic rehabilitation of the treatment plants, with either on-farm or post-harvest interventions or both, resulted in CERs within the range of US$40/DALY to US$57/DALY. However, the CERs for the construction of a new wastewater treatment plant either as an independent intervention or in combination with on-farm and post-harvest interventions were unattractive in view of health-risk reduction for wastewater irrigation. Although attractive, the CERs of non-treatment options are largely dependent on compliance (adoption) by farmers and food vendors. In this regard, the CER increased by almost fivefold when the adoption rate was only 25 per cent by farmers and food vendors; but was attractive as long as adoption rates did not fall below 70 per cent. On the other hand, the success of the treatment option depends on the functionality of the treatment plants which is not without challenges in a country like Ghana. Thus, this chapter stresses the need for a balanced risk-management approach through a combination of treatment and non-treatment interventions to hedge against failures that may affect CERs at any end. While this chapter provides a contribution to the debate on interventions for health-risk mitigation in wastewater irrigation, more case studies would be useful to verify the data presented here.
7 Jampani, Mahesh; Amerasinghe, Priyanie; Pavelic, Paul. 2015. An integrated approach to assess the dynamics of a peri-urban watershed influenced by wastewater irrigation. Journal of Hydrology, 523:427-440. [doi: https://doi.org/10.1016/j.jhydrol.2015.02.001]
Suburban agriculture ; Watersheds ; Land use ; Hydrology ; Socioeconomic environment ; Farmers ; Wastewater irrigation ; Groundwater irrigation ; Water use ; Water quality ; Leaf vegetables ; Aquifers ; Nutrients ; Labour costs ; Irrigated land ; Canal irrigation ; Rice ; Health hazards / India / Hyderabad
(Location: IWMI HQ Call no: e-copy only Record No: H047066)
(3.38 MB)
In many urban and peri-urban areas of India, wastewater is under-recognized as a major water resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha) in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability for agriculture and challenges in potential irrigated area development towards wastewater use. This integrated approach showed that the change in the total irrigated area was marginal over the decade, whereas the built-up area within the watershed boundaries doubled and there was a distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters of the water used and was largely derived from wastewater. The remainder was groundwater from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the wastewater was of value, although they were also interested to pay modest amounts for additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was attributed to increased profitability due to the high urban demand. The unutilised scrubland within the watershed has the potential for irrigation development, but the major constraints appear to be unavailability of labour and high land values rather than water availability. The study provides evidence to support the view that the opportunistic use of wastewater and irrigation practices, in general, will continue even under highly evolving peri-urban conditions, to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for agriculture, with flow-on benefits including improved public health and protection of ecosystem services.
8 Bellwood-Howard, I.; Haring, V.; Karg, Hanna; Roessler, R.; Schlesinger, J.; Shakya, M. 2015. Characteristics of urban and peri-urban agriculture in West Africa: results of an exploratory survey conducted in Tamale (Ghana) and Ouagadougou (Burkina Faso) Colombo, Sri Lanka: International Water Management Institute (IWMI) 38p. (IWMI Working Paper 163) [doi: https://doi.org/10.5337/2015.214]
Urban agriculture ; Peri-urban agriculture ; Farming systems ; Farmers ; Seasonal cropping ; Cultivation ; Soil sampling ; Soil fertility ; Households ; Livestock ; Landownership ; Water availability ; Wastewater ; Irrigation ; Market prices ; Leaf vegetables ; Inorganic fertilizers ; Organic fertilizers ; Villages ; Surveys / West Africa / Ghana / Burkina Faso / Tamale / Ouagadougou
(Location: IWMI HQ Call no: IWMI Record No: H047216)
(2 MB)
The report summarizes key results from surveys carried out on urban and peri-urban agriculture (UPA) in Tamale (Ghana) and Ouagadougou (Burkina Faso) in 2013. The aim was to provide a broad overview of the state of UPA in the study cities and a basis for future research endeavors. The randomized sampling approach used aerial photography to identify 10 sites in different categories of farm in each city. Farmers provided information on their cropping and livestock-rearing activities. There were similarities between the cities, but the differences in the expression of UPA in Tamale and Ouagadougou were more intriguing, as in farm sizes, crops grown and livestock ownership. Farmers were particularly concerned about diminishing access to land in Tamale, where sales by chiefs to private investors were accelerating. In Ouagadougou, formal reallocation of land to homeowners by the state had similarly decreased available farmland. Water availability was a universal concern, and the quality of water used for irrigation was potentially more questionable in Ouagadougou than in Tamale. The results point to the need for further work on uncontaminated, perennial water sources and soil fertility management, alongside focuses on commercialization of animal production, and the legal, political and institutional context of UPA in different West African cities.
9 Woldetsadik, D.; Drechsel, Pay; Keraita, B.; Marschner, B.; Itanna, F.; Gebrekidan, H. 2016. Effects of biochar and alkaline amendments on cadmium immobilization, selected nutrient and cadmium concentrations of lettuce (Lactuca sativa) in two contrasting soils. SpringerPlus, 5:1-16. [doi: https://doi.org/10.1186/s40064-016-2019-6]
Alkalinity ; Cadmium ; Immobilization ; Nutrients ; Cadmium ; Leaf vegetables ; Lettuces ; Soil sampling ; pH ; Faecal coliforms ; Nitrates ; Carbon ; Heavy metals ; Waste treatment
(Location: IWMI HQ Call no: e-copy only Record No: H047506)
(0.85 MB)
To assess the efficiency of seven treatments including biochars produced from dried faecal matter and manures as stabilizing agents of cadmium (Cd)-spiked soils, lettuce was grown in glasshouse on two contrasting soils. The soils used were moderately fertile silty loam and less fertile sandy loam and the applied treatments were 7 % w/w. The reduction of bioavailable Cd (ammonium nitrate extractable) and its phytoavailability for lettuce were used as assessment criteria in the evaluation of stabilization performance of each treatment. Moreover, the agronomic values of the treatments were also investigated. Ammonium nitrate extraction results indicated that faecal matter biochar, cow manure biochar and lime significantly reduced bioavailable Cd by 84–87, 65–68 and 82–91 %, respectively, as compared to the spiked controls. Unpredictably, coffee husk biochar induced significant increment of Cd in NH4NO3 extracts. The immobilization potential of faecal matter biochar and lime were superior than the other treatments. However, lime and egg shell promoted statistically lower yield and P, K and Zn concentrations response of lettuce plants compared to the biochar treatments. The lowest Cd and highest P tissue concentrations of lettuce plants were induced by faecal matter and cow manure biochar treatments in both soils. Additionally, the greatest Cd phytoavailability reduction for lettuce was induced by poultry litter and cow manure biochars in the silty loam soil. Our results indicate that faecal matter and animal manure biochars have shown great potential to promote Cd immobilization and lettuce growth response in heavily contaminated agricultural fields.
10 Karg, H.; Drechsel, Pay; Akoto-Dans, E. K.; Glaser, R.; Nyarko, G.; Buerkert, A. 2016. Foodsheds and city region food systems in two West African cities. Sustainability, 8(12):1-32. [doi: https://doi.org/10.3390/su8121175]
Food chains ; Food supply ; Food consumption ; Food habits ; Food production ; Urban environment ; Urban population ; Climate change ; Crops ; Livestock ; Vegetables ; Leaf vegetables ; Organic wastes / West Africa / Ghana / Burkina Faso / Tamale / Ouagadougou
(Location: IWMI HQ Call no: e-copy only Record No: H047875)
In response to changing urban food systems, short supply chains have been advocated to meet urban food needs while building more sustainable urban food systems. Despite an increasing interest in urban food supply and the flows of food from production to consumption, there is a lack of empirical studies and methodologies which systematically analyse the actual proportion and nutritional significance of local and regional food supplied to urban markets. The aim of this empirical study therefore was to compare the geographical sources supplying food to the urban population (“foodsheds”) in Tamale, Ghana and Ouagadougou, Burkina Faso, to record the supplied quantities and to assess the level of interaction between the sources and the respective city. The study was conducted over two years, covering the seasons of abundant and short supply, via traffic surveys on the access roads to the two cities, and in the Tamale markets, resulting altogether in more than 40,000 records of food flow. Results indicated that food sources were highly crop- and season-specific, ranging from one-dimensional to multi-dimensional foodsheds with diverse sources across seasons. Across the commodity-specific foodsheds, city region boundaries were established. Within the proposed city region a relatively large proportion of smallholders contributed to urban food supply, taking advantage of the proximity to urban markets. While food provided from within the city region offers certain place-based benefits, like the provision of fresh perishable crops, a larger geographical diversity of foodsheds appeared to enhance the resilience of urban food systems, such as against climate related production failures.
11 Woldetsadik, D.; Drechsel, Pay; Keraita, B.; Itanna, F.; Erko, B.; Gebrekidan, H. 2017. Microbiological quality of lettuce (Lactuca sativa) irrigated with wastewater in Addis Ababa, Ethiopia and effect of green salads washing methods. International Journal of Food Contamination, 4:1-9. [doi: https://doi.org/10.1186/s40550-017-0048-8]
Microbiological analysis ; Leaf vegetables ; Lettuces ; Wastewater irrigation ; Faecal coliforms ; Helminths ; WHO ; Contamination ; Irrigation water ; Risk reduction ; Bacteriological analysis ; Farmland ; Wastewater treatment ; Households ; Water pollution ; Water use / Ethiopia / Addis Ababa
(Location: IWMI HQ Call no: e-copy only Record No: H047981)
http://link.springer.com/content/pdf/10.1186%2Fs40550-017-0048-8.pdf
https://vlibrary.iwmi.org/pdf/H047981.pdf
https://vlibrary.iwmi.org/pdf/H047981.pdf
(561 KB)
Background: In Addis Ababa, where irrigation water for vegetable production is commonly derived from the highly polluted Akaki river, information on microbial contamination of water and irrigated vegetable is scanty. An assessment was done to determine the microbiological quality of irrigation water and lettuce harvested from 10 urban farming sites of Addis Ababa. The efficacy of 5 lettuce washing methods were also assessed. A total of 210 lettuce and 90 irrigation water samples were analyzed for faecal coliform and helminth eggs population levels. Results: The mean faecal coliform levels of irrigation water ranged from 4.29-5.61 log10 MPN 100 ml-1, while on lettuce, the concentrations ranged from 3.46-5.03 log10 MPN 100 g-1. Helminth eggs and larvae were detected in 80% of irrigation water and 61% of lettuce samples. Numbers ranged from 0.9-3.1 eggs 1000 ml-1 and 0.8-3.7 eggs 100 g-1 wet weight for irrigation water and lettuce, respectively. The helminth eggs identified included those of Ascaris lumbricoides, Hookworm, Enterobius vermicularis, Trichuris trichiura, Taenia and Strongloyides larvae. Ascaris lumbricoides and Hookworm were most prevalent in both irrigation water and lettuce samples. Compared with the WHO recommendations and international standards, the faecal coliform and helminth eggs levels in irrigation water and lettuce samples exceeded the recommended levels. Irrespective of the tested washing methods, faecal coliform and helminth eggs levels were somehow reduced. Among the washing methods, potable tap water washing - rinsing (2 min) followed by dipping in 15 000 ppm vinegar solution for a minute supported the highest faecal coliorm reduction of 1.7 log10 units, whereas lowest reduction of 0.8 log10 units was achieved for the same procedure without vinegar. Conclusion: Compared with international standards, both faecal coliform and helminth eggs levels exceeded recommended thresholds in water and lettuce, but still in a potential risk range which can be easily mitigated if farmers and households are aware of the potential risk. Aside preventing occupational exposure, potential risk reduction programs should target households which have so far no guidance on how best to wash vegetables. The result of the present study suggest that the vinegar based washing methods are able to reduce faecal coliform towards low level while the physical washing with running water may help to substantially decrease potential risk of helminth parasitic infections.
12 Karg, H.; Schlesinger, J. 2018. Open space farming. In Karg, H.; Drechsel, Pay (Eds.). Atlas of West African urban food systems: examples from Ghana and Burkina Faso. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). pp.15-29.
Farming systems ; Open spaces ; Urban agriculture ; Irrigated farming ; Wastewater irrigation ; Shifting cultivation ; Dry season ; Wet season ; Cultivated land ; Crop production ; Leaf vegetables ; Soil management ; Wastewater treatment ; Biochar ; Pesticide application ; Health hazards ; Farmers / Ghana / Burkina Faso / Tamale / Ouagadougou / Boulmiougou / Gumbehene / Kossodo
(Location: IWMI HQ Call no: e-copy only Record No: H049017)
(2.19 MB)
13 Truchado, P.; Gil, M. I.; Lopez, C.; Garre, A.; Lopez-Aragon, R. F.; Bohme, K.; Allende, A. 2021. New standards at European Union level on water reuse for agricultural irrigation: are the Spanish wastewater treatment plants ready to produce and distribute reclaimed water within the minimum quality requirements? International Journal of Food Microbiology, 365:109352. (Online first) [doi: https://doi.org/10.1016/j.ijfoodmicro.2021.109352]
Water reuse ; Irrigation water ; Wastewater treatment plants ; Water quality ; Regulations ; Irrigation systems ; Pathogenic microorganisms ; Escherichia coli ; Microbiological risk assessment ; Fruits ; Leaf vegetables ; Indicators / Spain
(Location: IWMI HQ Call no: e-copy only Record No: H050599)
(0.85 MB)
The new European regulation on minimum quality requirements (MQR) for water reuse (EU, 2020/741) was launched in May 2020 and describes the directives for the use of reclaimed water for agricultural irrigation. This Regulation will be directly applicable in all Member States from 26 June 2023. Since its publication in 2020, concerns have raised about potential non-compliance situations in water reuse systems. The present study represents a case study where three different water reuse systems have been monitored to establish their compliance with the MQR. Each water reuse system includes a wastewater treatment plant (WWTP), a distribution/storage system and an end-user point, where water is used for irrigation of leafy greens. The selected water reuse systems allowed us to compare the efficacy of water treatments implemented in two WWTPs as well as the impact of three different irrigation systems (drip, furrow and overhead irrigation). The presence and concentration of indicator microorganisms (Escherichia coli and C. perfringens spores) as well as pathogenic bacteria (Shiga toxin-producing, E. coli (STEC), E. coli O157:H7, and Salmonella spp.) were monitored in different sampling points (influent and effluent of the WWTPs, water reservoirs located at the distribution system and the end-user point at the irrigation system as well as in the leafy greens during their growing cycle. Average levels of E. coli (0.73 ± 1.20 log cfu E. coli/100 mL) obtained at the point where the WWTP operator delivers reclaimed water to the next actor in the chain, defined in the European regulation as the ‘point of compliance’, were within the established MQR (<1 log cfu/100 mL) (EU, 2020/741). On the other hand, average levels of E. coli at the end-user point (1.0 ± 1.2 log cfu/100 mL) were below the recommended threshold (2 log cfu E. coli/100 mL) for irrigation water based on the guidance document on microbiological risks in fresh fruits and vegetables at primary production (EC, 2017/C_163/01). However, several outlier points were observed among the samples taken at the irrigation point, which were linked to a specific cross-contamination event within the distribution/storage system. Regarding pathogenic bacteria, water samples from the influent of the WWTPs showed a 100% prevalence, while only 5% of the effluent samples were positive for any of the monitored pathogenic bacteria. Obtained results indicate that reclaimed water produced in the selected water reuse system is suitable to be used as irrigation water. However, efforts are necessary not only in the establishment of advance disinfection treatments but also in the maintenance of the distribution/storage systems.
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