Your search found 8 records
(Location: IWMI HQ Record No: H040972)
(0.22 MB)
This study investigates helminth eggs removal and inactivation efficiency in a treatment process combining faecal sludge (FS) dewatering and subsequent co-composting with organic solid waste as a function of windrow turning frequency. Fresh public toilet sludge and septage mixed at a 1:2 ratio were dewatered on a drying bed. Biosolids with initial loads of 25–83 helminth eggs/g total solids (TS) were mixed with solid waste as bulking material for co-composting at a 1:2 volume ratio. Two replicate sets of compost heaps were mounted in parallel and turned at different frequencies during the active composting period: (i) once every 3 days and (ii) once every 10 days. Turning frequency had no effect on helminth eggs removal efficiency. In both setups, helminth eggs were reduced to o1 viable egg/g TS, thereby complying with the WHO guidelines 2006 for the safe reuse of FS.
2 Ensink, Jeroen H. J.; Brooker, S.; Cairncross, S.; Scott, Christopher A. 2006. Wastewater use in India: the impact of irrigation weirs on water quality and farmer health. In Water, Engineering and Development Centre (WEDC). Sustainable development of water resources, water supply and environmental sanitation: 32nd WEDC International Conference, Bandaranaike Memorial International Conference Hall, Colombo, Sri Lanka, 13th - 17th November 2006. Preprints. Leicestershire, UK: Water, Engineering and Development Centre (WEDC) pp.101-104.
(Location: IWMI HQ Call no: 333.91 G000 WAT Record No: H041033)
3 Seidu, R.; Drechsel, Pay; Amoah, Philip; Lofman, Owe; Heistad, Arve; Fodge, Madeliene; Jenssen, P.; Stenstrom, T. A. 2008. Quantitative microbial risk assessment of wastewater and faecal sludge reuse in Ghana. In Hazel, J. (Ed.). Proceedings of the 33rd WEDC International Conference on Access to Sanitation and Safe Water: Global Partnerships and Local Actions, Accra, Ghana, 7-11 April 2008. Leicestershire, UK: Water, Engineering and Development Centre (WEDC). pp.90-97.
(Location: IWMI HQ Call no: IWMI 631.7.5 G200 SEI Record No: H041285)
(Location: IWMI HQ Call no: IWMI 631.7.5 G200 SEI Record No: H041489)
Quantitative Microbial Risk Assessment (QMRA) models with 10,000 Monte Carlo simulations were applied to ascertain the risks of rotavirus and Ascaris infections for farmers using different irrigation water qualities and consumers of lettuce irrigated with the different water qualities after allowing post-harvest handling. A tolerable risk (TR) of infection of 7.7 £ 1024 and 1 £ 1022 per person per year were used for rotavirus and Ascaris respectively. The risk of Ascaris infection was within a magnitude of 1022 for farmers accidentally ingesting drain or stream irrigation water; ,100 for farmers accidentally ingesting farm soil and 100 for farmers ingesting any of the irrigation waters and contaminated soil. There was a very low risk (1025) of Ascaris infection for farmers using pipe 2 water. For consumers, the annual risks of Ascaris and rotavirus infections were 100 and 1023 for drain and stream irrigated lettuce respectively with slight increases for rotavirus infections along the post-harvest handling chain. Pipe irrigated lettuce recorded a rotavirus infection of 1024 with no changes due to post harvest handling. The assessment identified on-farm soil contamination as the most significant health hazard.
5 Navarro, I.; Teunis, P.; Moe, C.; Jimenez, B. 2010. Approaches to evaluate and develop health risk-based standards using available data. 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.63-88. (Also in French).
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE Record No: H042604)
(0.36 MB)
Information on the dose-response relationship of waterborne and foodborne enteric pathogens is an important component in any consideration of the health risks that may be associated with wastewater, sludge or excreta reuse for food-crop production. The three main sources of information on dose-response relationships are: human challenge studies, animal studies and outbreak investigations. Doseresponse information on four representative enteric pathogens (Norwalk virus, E. coli O157:H7, Giardia lamblia and Ascaris lumbricoides) is presented as examples. In addition to dose-response information, the application of quantitative microbial risk assessment to examine the potential health risks associated with the consumption of food crops irrigated with wastewater or fertilized with biosolids requires information on several factors. These are transmission pathways, occurrence (frequency and concentration) of pathogens in wastewater and biosolids, persistence of pathogen viability or infectivity in the environment and on the food crops, and crop consumption (amount and frequency). Assessments of the risks of Giardia and Ascaris infection associated with food crops in several scenarios are presented and illustrate how WHO Guidelines and pathogen reduction measures (such as produce-washing) may have a significant or negligible impact on reducing the risks of infection associated with food crops irrigated or fertilized with wastewater and biosolids.
6 Mara, D.; Hamilton, A. J.; Sleigh, A.; Karavarsamis, N.; Seidu, R. 2010. Tools for risk analysis: updating the 2006 WHO guidelines. 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.89-100. (Also in French).
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 DRE Record No: H042605)
(0.23 MB)
This chapter reviews developments since the WHO Guidelines for the safe use of wastewater in agriculture were published in 2006. The six main developments are: the recognition that the tolerable additional disease burden may be too stringent for many developing countries; the benefits of focusing on single-event infection risks as a measure of outbreak potential when evaluating risk acceptability; a more rigorous method for estimating annual risks; the availability of dose-response data for norovirus; the use of QMRA to estimate Ascaris infection risks; and a detailed evaluation of pathogen reductions achieved by produce-washing and disinfection. Application of the developments results in more realistic estimates of the pathogen reductions required for the safe use of wastewater in agriculture and consequently permits the use of simpler wastewater treatment processes.
7 Navarro, I.; Teunis, P.; Moe, C.; Jimenez, B. 2011. Approches pour evaluer et etablir des normes fondees sur les risques sanitaires a partir des donnees disponibles. In French. [Approaches to evaluate and develop health risk-based standards using available data]. 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.67-89. (Also in English).
(Location: IWMI HQ Call no: IWMI Record No: H044461)
(5.96MB)
Information on the dose-response relationship of waterborne and foodborne enteric pathogens is an important component in any consideration of the health risks that may be associated with wastewater, sludge or excreta reuse for food-crop production. The three main sources of information on dose-response relationships are: human challenge studies, animal studies and outbreak investigations. Doseresponse information on four representative enteric pathogens (Norwalk virus, E. coli O157:H7, Giardia lamblia and Ascaris lumbricoides) is presented as examples. In addition to dose-response information, the application of quantitative microbial risk assessment to examine the potential health risks associated with the consumption of food crops irrigated with wastewater or fertilized with biosolids requires information on several factors. These are transmission pathways, occurrence (frequency and concentration) of pathogens in wastewater and biosolids, persistence of pathogen viability or infectivity in the environment and on the food crops, and crop consumption (amount and frequency). Assessments of the risks of Giardia and Ascaris infection associated with food crops in several scenarios are presented and illustrate how WHO Guidelines and pathogen reduction measures (such as produce-washing) may have a significant or negligible impact on reducing the risks of infection associated with food crops irrigated or fertilized with wastewater and biosolids.
8 Mara, D.; Hamilton, A. J.; Sleigh, A.; Karavarsamis, N.; Seidu, R. 2011. Outils pour l’analyse des risques: mise a jour des directives de 2006 de l’OMS. In French. [Tools for risk analysis: updating the 2006 WHO guidelines]. 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.95-108. (Also in English).
(Location: IWMI HQ Call no: IWMI Record No: H044462)
(5.96MB)
This chapter reviews developments since the WHO Guidelines for the safe use of wastewater in agriculture were published in 2006. The six main developments are: the recognition that the tolerable additional disease burden may be too stringent for many developing countries; the benefits of focusing on single-event infection risks as a measure of outbreak potential when evaluating risk acceptability; a more rigorous method for estimating annual risks; the availability of dose-response data for norovirus; the use of QMRA to estimate Ascaris infection risks; and a detailed evaluation of pathogen reductions achieved by produce-washing and disinfection. Application of the developments results in more realistic estimates of the pathogen reductions required for the safe use of wastewater in agriculture and consequently permits the use of simpler wastewater treatment processes.
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