Tag Archives: household water treatment

WASHplus Weekly-Focus on the health impacts of WASH interventions

Issue 121 November 1, 2013 | Focus on the Health Impacts of WASH Interventions

This issue updates the May 2013 Weekly on WASH-related diseases. Included are links to four reports, seven journal articles plus 14 Weeklies on WASH and various health issues. Studies in this issue review the health impacts of drought, WASH and nutrition, behavior change frameworks, and WASH and HIV/AIDS.


Considerations for Policy Development and Scaling-Up Household Water Treatment and Safe Storage with Communicable Disease Prevention Efforts, 2013. World Health Organization. (Full text, pdf)
The overall consensus from a group of technical experts was that existing meta-analyses, individual research reports, and WHO guidelines provide sufficient support for scaling-up household water treatment and safe storage (HWTS). More can and should be done to integrate HWTS into HIV, child and maternal health, dengue and vector control, and other targeted efforts. Some of the report’s recommendations are: link HWTS with efforts to rapidly expand HIV testing in order to reach the global HIV target of treating 15 million by 2015; increase implementation of HWTS to end preventable child deaths from pneumonia and diarrhea by 2025; and develop and implement preventive interventions that jointly address fecal contamination and vector breeding in household water storage containers.

Effects of Early-Life Exposure to Sanitation on Childhood Cognitive Skills: Evidence from India’s Total Sanitation Campaign, 2013. D Spears. (Full text, pdf)
This study focuses on the effects on childhood cognitive achievement of early life exposure to India’s Total Sanitation Campaign (TSC), a large government program that encouraged local governments to build and promote use of inexpensive pit latrines. The researchers concluded that six-year-olds exposed to TSC in their first year of life were more likely to recognize letters and simple numbers. Results suggest that open defecation is an important threat to the human capital of the Indian labor force, and a program that is feasible to low capacity governments in developing countries could improve average cognitive skills.

Integrating Water, Sanitation, and Hygiene into Nutrition Programming, 2013. WASHplus. (Link, pdf)
Diarrhea, pneumonia, and birth complications are the top three killers of children under age 5 worldwide. Diarrhea is also a leading cause of undernutrition in this age group, and one-third to one-half of all child mortality cases are linked to undernutrition. If mothers and other caregivers used basic hygiene practices and had better access to safe water and adequate sanitation this could greatly reduce under-5 deaths and improve child nutrition.

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The effect of bottle scratches on SODIS water disinfection

Concerns that bottle scratches negatively influence the quality of solar water disinfection (SODIS) are unfounded, a new NGO study reveals. Ambient temperature and bottle diameter, however, do greatly influence disinfection effectiveness, the study finds.

The NGO Nature Healing Nature has been promoting SODIS for many years in Africa and South America. While working in Togo, staff heard that a respected nonprofit organization had stopped promoting SODIS because they noticed many of the plastic bottles being used for SODIS were noticeably scratched after six months of use. They hypothesized the scratches would interfere with UV transmission and thus the effectiveness of purification. Rather than ignore their hypothesis, Nature Healing Nature decided to investigate if increased bottle scratch density results in decreased solar disinfection quality.

Test bottles (three scratched). Photo: Nature Healing Nature

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USAID/CDC – Proven Household Water Treatment Options Fact Sheet

Preventing Diarrheal Disease in Developing Countries: Proven Household Water Treatment Options. USAID, CDC, November 2010.

Download Full-text (pdf, 1.19MB)

Five interventions – chlorination, ceramic filtration, slow sand filtration, solar disinfection, and PUR – have been proven to reduce diarrhea in users in developing countries and improve the microbiological quality of stored household water and are discussed below. The most appropriate HWTS option for a location depends on existing water and sanitation conditions, water quality, cultural acceptability, implementation feasibility, availability of HWTS technologies, and other local conditions.

Household Water Treatment and the Millennium Development Goals

Environ. Sci. Technol., August 30, 2010

Household Water Treatment and the Millennium Development Goals: Keeping the Focus on Health

Full-text: http://pubs.acs.org/doi/full/10.1021/es1018674

Thomas F. Clasen. London School of Hygiene & Tropical Medicine

Other studies by Thomas Clasen – http://ehbibliography.wordpress.com/category/clasen-t/

Waterborne diseases such as diarrhea are a major killer in low-income settings, particularly of young children. For those without access to safe drinking water, household water treatment, such as boiling, chlorinating, and filtering water in the home, when combined with safe storage (HWTS) can significantly improve water quality and prevent disease, thereby contributing to the child survival and other health priorities encompassed within the Millennium Development Goals (MDGs). There is uncertainly, however, about whether HWTS should count toward the MDG water target, which promotes “sustainable access to safe drinking water”.

This paper reviews the relevant research and concludes that it should not. Although HWTS can significantly improve water quality, it does not improve water quantity and access—key aspects of the MDG water target that are essential for optimal improvements in health and development. A policy that excludes HWTS from the MDG water target will discourage governments from diverting scarce public resources from comprehensive and long-term improvements in water supplies. At the same time, the health-oriented MDGs provide a sufficient case for scaling up effective and appropriate HWTS among target populations. Moreover, a health-based strategy for HWTS will help ensure that promotion of the intervention is driven by measurable improvements in outcomes rather than inputs, thus encouraging advances in both hardware and programmatic delivery that will make HWTS more effective, appropriate, and accessible to vulnerable populations.

Effect of water quality, hygiene and sanitation in preventing diarrhoea deaths

Researchers propose diarrhoea risk reductions of 48, 17 and 36%, associated respectively, with handwashing with soap, improved water quality and excreta disposal as the estimates of effect for the Lives Saved Tool (LiST) model [1].

LiST is a new computer-based planning tool to help estimate the impact of scaling-up maternal, newborn and child health interventions. LiST was developed by a consortium of academic and international organizations, led by Institute of International Programs at the Johns Hopkins Bloomberg School.

Researchers led by Prof. Sandy Cairncross of the London School of Hygiene & Tropical Medicine, drew on three systematic reviews, two of them for the Cochrane Collaboration, to determine the estimated effect on diarrhoea mortality of the three interventions.

The striking effect of handwashing with soap (48% reduction) was found to be consistent across various study designs and pathogens, though it depended on access to water. The effect of (household) water treatment appeared similarly large, but was not found in few blinded studies, suggesting that it might be partly due to the placebo effect. The researchers found very little rigorous evidence for the health benefit of sanitation; four intervention studies were eventually identified, though they were all quasi-randomized, had morbidity as the outcome, and were in Chinese.

While most of the evidence was found to be of poor quality and more trials were required, the evidence was nonetheless strong enough to support the provision of water supply, sanitation and hygiene for all.

[1] Cairncross, S., Hunt, C., Boisson, S., Bostoen, K., Curtis, V., Fung, I.C. and Schmidt, W.P. (2010). Water, sanitation and hygiene for the prevention of diarrhoea. International journal of epidemiology ; vol. 39 (Suppl. 1) ; p. i193-i205. DOI:10.1093/ije/dyq035

The complete issue of the April 2010 supplement of the International journal of epidemiology is devoted to the development and use of the Lives Saved Tool (LiST). Other articles deal with rotavirus vaccine, zinc treatment for diarrhoea, antibiotics for dysentery, and oral rehydration solution. All articles are free to download.

UNICEF/PSI household water treatment and safe storage video

Saving Lives with Safe Water: Household Water Treatment and Safe Storage

UNICEF created this video in partnership with Population Services International (PSI) platforms to celebrate the Safe Drinking Water Project. The project, funded by American Express, is underway in Guinea, Angola, the Democratic Republic of Congo and Tanzania, and aims to change behaviors in the home. Even if water flows safe and clear from a local pump, dirty containers, dirty hands or unsanitary storage can contaminate it leading to disease, and even death. The Project informs people about the dangers of unsafe water, and how they can protect themselves by treating their daily supply at home, with inexpensive products available in their local markets

Bibliography on household water treatment and safe storage

Environmental Health at USAID has compiled an annotated bibliography of 21 journal articles on household water treatment and safe storage that were published from January-July 2009.

Link: http://www.ehproject.org/PDF/ehkm/bibliography-hwt_july2009.pdf (pdf, 70KB)

Below are 3 of the 21 studies from the bibliography:

1 – Am J Trop Med Hyg. 2009 May; 80(5):819-23.
Laboratory assessment of a gravity-fed ultra-filtration water treatment device designed for household use in low-income settings.

Clasen T, Naranjo J, Frauchiger D, Gerba C.

Interventions to improve water quality, particularly when deployed at the household level, are an effective means of preventing endemic diarrheal disease, a leading cause of mortality and morbidity in the developing world. We assessed the microbiologic performance of a novel water treatment device designed for household use in low-income settings. The device employs a backwashable hollow fiber ultrafiltration cartridge and is designed to mechanically remove enteric pathogenic bacteria, viruses, and protozoan cysts from drinking water without water pressure or electric power. In laboratory testing through 20,000 L (approximately 110% of design life) at moderate turbidity (15 nephelometric turbidity unit [NTU]), the device achieved log(10) reduction values of 6.9 for Escherichia coli, 4.7 for MS2 coliphage (proxy for enteric pathogenic viruses), and 3.6 for Cryptosporidium oocysts, thus exceeding levels established for microbiological water purifiers. With periodic cleaning and backwashing, the device produced treated water at an average rate of 143 mL/min (8.6 L/hour) (range 293 to 80 mL/min) over the course of the evaluation. If these results are validated in field trials, the deployment of the unit on a wide scale among vulnerable populations may make an important contribution to public health efforts to control intractable waterborne diseases.

4 – Environ Sci Technol. 2009 Feb 15; 43(4):986-92.
Household water treatment in poor populations: is there enough evidence for scaling up now?

Schmidt WP, Cairncross S.
Point-of-use water treatment (household water treatment, HWT) has been advocated as a means to substantially decrease the global burden of diarrhea and to contribute to the Millennium Development Goals. To determine whether HWT should be scaled up now, we reviewed the evidence on acceptability, scalability, adverse effects, and nonhealth benefits as the main criteria to establish how much evidence is needed before scaling up. These aspects are contrasted with the evidence on the effect of HWT on diarrhea. We found that the acceptability and scalability of HWT is still unclear, and that there are substantial barriers making it difficult to identify populations that would benefit most from a potential effect. The nonhealth benefits of HWT are negligible. Health outcome trials suggest that HWT may reduce diarrhea by 30-40%. The problem of bias is discussed. There is evidence that the estimates may be strongly biased. Current evidence does not exclude that the observed diarrhea reductions are largely or entirely due to bias. We conclude that widespread promotion of HWT is premature given the available evidence. Further acceptability studies and large blinded trials or trials with an objective health outcome are needed before HWT can be recommended to policy makers and implementers.

7 – Int J Epidemiol. 2009 Jul 2.

Evaluation of a pre-existing, 3-year household water treatment and handwashing intervention in rural Guatemala.

Arnold B, Arana B, Mäusezahl D, Hubbard A, Colford JM Jr.

BACKGROUND: The promotion of household water treatment and handwashing with soap has led to large reductions in child diarrhoea in randomized efficacy trials. Currently, we know little about the health effectiveness of behaviour-based water and hygiene interventions after the conclusion of intervention activities.

METHODS: We present an extension of previously published design (propensity score matching) and analysis (targeted maximum likelihood estimation) methods to evaluate the behavioural and health impacts of a pre-existing but non-randomized intervention (a 3-year, combined household water treatment and handwashing campaign in rural Guatemala). Six months after the intervention, we conducted a cross-sectional cohort study in 30 villages (15 intervention and 15 control) that included 600 households, and 929 children <5 years of age.

RESULTS: The study design created a sample of intervention and control villages that were comparable across more than 30 potentially confounding characteristics. The intervention led to modest gains in confirmed water treatment behaviour [risk difference = 0.05, 95% confidence interval (CI) 0.02-0.09]. We found, however, no difference between the intervention and control villages in self-reported handwashing behaviour, spot-check hygiene conditions, or the prevalence of child diarrhoea, clinical acute lower respiratory infections or child growth.

CONCLUSIONS: To our knowledge this is the first post-intervention follow-up study of a combined household water treatment and handwashing behaviour change intervention, and the first post-intervention follow-up of either intervention type to include child health measurement. The lack of child health impacts is consistent with unsustained behaviour adoption. Our findings highlight the difficulty of implementing behaviour-based household water treatment and handwashing outside of intensive efficacy trials.