Household Drinking Water Quality Updates
Determinants of Caregivers’ Use and Adoption of Household Water Chlorination: A Qualitative Study with Peri-urban Communities in the Peruvian Amazon
Determinants of Caregivers’ Use and Adoption of Household Water Chlorination: A Qualitative Study with Peri-urban Communities in the Peruvian Amazon. Am Jnl Trop Med Hyg, July 2015.
Authors: Jessica D. Rothstein, Elli Leontsini, et al.
The gap between the efficacy and the effectiveness of household water treatment in reducing diarrhea-related morbidity indicates the need for a better understanding of the determinants of long-term behavior change. To explore the barriers to drinking water chlorination in the Peruvian Amazon, where diarrhea is endemic among under-5 children, we conducted qualitative research with 23 caregivers from peri-urban communities of Iquitos, Peru. Our inquiry drew on the Transtheoretical Model of behavior change and the Integrated Behavioral Model for Water, Sanitation, and Hygiene to identify the most relevant contextual, psychosocial, and technological determinants of initial action and long-term adoption of chlorination.
Our findings suggest that the decision to try out this practice resulted from the combined effect of knowledge of chlorination benefits and product availability and affordability. Progress from action to adoption was influenced by caretakers’ understanding of dosage, the packaging of chlorine products, knowledge and skills for multipurpose laundry bleach, the taste of treated water, and reinforcement. This analysis suggests that a focus on these determinants and the household domain may help to improve the sustainability of future intervention efforts.
Coping with household water scarcity in the savannah today: Implications for health and climate change into the future
Coping with household water scarcity in the savannah today: Implications for health and climate change into the future. Earth Interact. 2015 doi:10.1175/EI-D-14-0039.1, in press.
Authors: Amber L. Pearson, Jonathan D. Mayer, David J. Bradley
Even as millions live without reliable access to water, very little is known about how households cope with scarcity. The aims of this research were to: 1) understand aspects of water scarcity in three rural villages in southwestern Uganda; 2) examine differences by demographics and type of source; 3) assess relationships between different factors related to water access; and 4) explore coping strategies used. Health implications and lessons learned that relate to future climate change are discussed.
Over half of the households relied on seasonal water sources. Of those accessing ‘permanent’ sources, ~30% experienced inaccessibility within the past two weeks. Self-reported better access to water was correlated with minutes spent walking to source and to some degree with the source being more public or shared. Those without access to public sources tended to migrate as the primary coping strategy. Water sharing and reciprocity appears crucial between wealthy and poor households, however, those from outside ethnic groups appear to be partially excluded. Middle income households followed by the poorest had the largest reliance on purchasing water to cope. These findings underscore how access to water resources, particularly in times of insecurity, involves social networks.
Knowledge, Information, and Water Treatment Behavior of Residents in the Kathmandu Valley, Nepal. The Development Journal of the South, Vol. 1, No. 1, 2015.
Authors: Hari Katuwal, Mona K Qassim, José A. Pagán, Jennifer A Thacher, Alok K. Bohara
In this paper, we examine determinants of water treatment behavior using survey data (N=1200) from Kathmandu, Nepal. In particular, this paper focuses on the impacts of knowledge, exposure to information, and community participation on drinking water treatment behavior. Previous research has found that income, education level, awareness, and exposure to media are major factors that impact the individual-level decision to treat water before using it. We contribute to this literature by explicitly examining how knowledge about waterborne diseases, exposure to water quality information campaigns, and participation in community organizations impact drinking water treatment behavior.
The results from probit regression analyses suggest that either a one percentage increase in the knowledge index or community participation index both increase the likelihood of utilizing drinking water treatment methods by about 0.17 percentage points. Households connected to the distribution system are 31 percentage points more likely to treat water compared to those that are not connected to the system. Multinomial results indicate that wealthier households use more than one treatment method.
Silver Dissolution and Release from Ceramic Water Filters. Env Sci Tech, June 2015.
Authors: Anjuliee M. Mittelman, Daniele S. Lantagne, Justine Rayner, and Kurt D. Pennell
Application of silver nanoparticles (nAg) or silver nitrate (AgNO3) has been shown to improve the microbiological efficacy of ceramic water filters used for household water treatment. Silver release, however, can lead to undesirable health effects and reduced filter effectiveness over time. The objectives of this study were to evaluate the contribution of nanoparticle detachment, dissolution, and cation exchange to silver elution, and to estimate silver retention under different influent water chemistries. Dissolved silver (Ag+) and nAg release from filter disks painted with 0.03 mg/g casein-coated nAg or AgNO3 were measured as a function of pH (5–9), ionic strength (1–50 mM), and cation species (Na+, Ca2+, Mg2+).
Silver elution was controlled by dissolution as Ag+ and subsequent cation exchange reactions regardless of the applied silver form. Effluent silver levels fell below the drinking water standard (0.1 mg/L) after flushing with 30–42 pore volumes of pH 7, 10 mM NaNO3 at pH 7. When the influent water was at pH 5, contained divalent cations or 50 mM NaNO3, silver concentrations were 5–10 times above the standard. Our findings support regular filter replacement and indicate that saline, hard, or acidic waters should be avoided to minimize effluent silver concentrations and preserve silver treatment integrity.
Efficacy of Handwashing with Soap and Nail Clipping on Intestinal Parasitic Infections in School-Aged Children
Efficacy of Handwashing with Soap and Nail Clipping on Intestinal Parasitic Infections in School-Aged Children: A Factorial Cluster Randomized Controlled Trial. PLoS Medicine, June 2015.
Authors: Mahmud Abdulkader Mahmud, Mark Spigt, et al.
Background - Intestinal parasitic infections are highly endemic among school-aged children in resource-limited settings. To lower their impact, preventive measures should be implemented that are sustainable with available resources. The aim of this study was to assess the impact of handwashing with soap and nail clipping on the prevention of intestinal parasite reinfections.
Methods and Findings - In this trial, 367 parasite-negative school-aged children (aged 6–15 y) were randomly assigned to receive both, one or the other, or neither of the interventions in a 2 × 2 factorial design. Assignment sequence was concealed. After 6 mo of follow-up, stool samples were examined using direct, concentration, and Kato-Katz methods. Hemoglobin levels were determined using a HemoCue spectrometer. The primary study outcomes were prevalence of intestinal parasite reinfection and infection intensity. The secondary outcome was anemia prevalence. Analysis was by intention to treat. Main effects were adjusted for sex, age, drinking water source, latrine use, pre-treatment parasites, handwashing with soap and nail clipping at baseline, and the other factor in the additive model. Fourteen percent (95% CI: 9% to 19%) of the children in the handwashing with soap intervention group were reinfected versus 29% (95% CI: 22% to 36%) in the groups with no handwashing with soap (adjusted odds ratio [AOR] 0.32, 95% CI: 0.17 to 0.62). Similarly, 17% (95% CI: 12% to 22%) of the children in the nail clipping intervention group were reinfected versus 26% (95% CI: 20% to 32%) in the groups with no nail clipping (AOR 0.51, 95% CI: 0.27 to 0.95). Likewise, following the intervention, 13% (95% CI: 8% to 18%) of the children in the handwashing group were anemic versus 23% (95% CI: 17% to 29%) in the groups with no handwashing with soap (AOR 0.39, 95% CI: 0.20 to 0.78). The prevalence of anemia did not differ significantly between children in the nail clipping group and those in the groups with no nail clipping (AOR 0.53, 95% CI: 0.27 to 1.04). The intensive follow-up and monitoring during this study made it such that the assessment of the observed intervention benefits was under rather ideal circumstances, and hence the study could possibly overestimate the effects when compared to usual conditions.
Conclusions - Handwashing with soap at key times and weekly nail clipping significantly decreased intestinal parasite reinfection rates. Furthermore, the handwashing intervention significantly reduced anemia prevalence in children. The next essential step should be implementing pragmatic studies and developing more effective approaches to promote and implement handwashing with soap and nail clipping at larger scales.
Factors Determining Water Treatment Behavior for the Prevention of Cholera in Chad. Am Jnl Trop Med Hyg, Apr 2015.
Authors: Jonathan Lilje, Hamit Kessely and Hans-Joachim Mosler
Cholera is a well-known and feared disease in developing countries, and is linked to high rates of morbidity and mortality. Contaminated drinking water and the lack of sufficient treatment are two of the key causes of high transmission rates. This article presents a representative health survey performed in Chad to inform future intervention strategies in the prevention and control of cholera.
To identify critical psychological factors for behavior change, structured household interviews were administered to N = 1,017 primary caregivers, assessing their thoughts and attitudes toward household water treatment according to the Risk, Attitude, Norm, Ability, and Self-regulation model. The intervention potential for each factor was estimated by analyzing differences in means between groups of current performers and nonperformers of water treatment. Personal risk evaluation for diarrheal diseases and particularly for cholera was very low among the study population. Likewise, the perception of social norms was found to be rather unfavorable for water treatment behaviors.
n addition, self-reported ability estimates (self-efficacy) revealed some potential for intervention. A mass radio campaign is proposed, using information and normative behavior change techniques, in combination with community meetings focused on targeting abilities and personal commitment to water treatment.
Evaluation of Microbial Water Quality Tests for Humanitarian Emergency and Development Settings. Procedia Engineering, Volume 107, 2015, Pages 237–246. Humanitarian Technology: Science, Systems and Global Impact 2015, HumTech2015.
Authors: Susan Murcott, Megan Keegan, Alison Hanson, Akshay Jain, Jason Knutson, Shuyue Liu, Jenny Tanphanich, Teng Ke Wong
How do you know if drinking water is safe? Or which microbial indicator tests work best when few side-by-side performance evaluations exist in real-world field sites? This research compares bacterial indicator test products inlow-resource settings in Ahmedabad, India and Tamale, Ghana. In India, three hydrogen sulfide (H2S) bacteria test products were evaluated: laboratory-made H2S, TARA Aquacheck and ORlab H2S, and compared to an EPA-certified standard, the IDEXX Quanti-Tray® 2000. In Ghana, 3 M Petrifilm™, Aquagenx CBT and Easygel® Cards were included in addition toH2S and Quanti-Tray® 2000. Results are presented in a Consumer Reports-style for easy comprehension.
Sanitary Survey of Public Drinking Water Sources: A Study Conducted in Slums of Bhubaneswar, Odisha, 2015. Health of the Urban Poor (HUP) Program.
Authors: Biraja Kabi Satapathy, Niladri Chakraborti.
The sanitary survey of drinking water sources was done in Bhubaneswar slums where PFI is running the Health of the Urban Poor Program. The purpose was to understand the risk to public drinking water sources based on onsite inspection and water testing of the source with field test for pipe water supply and H2 S bacteriological contamination test for all the sources. The study report gives details of the survey undertaken, its findings, and suggestions for ensuring drinking water quality in the slums of Odisha. The report tried to capture the result of the indicator-wise sanitary inspection and its relation with other indicators. We hope the study will be useful for the government for making some policy level corrections. We also hope that Government, Non Government and civil society organisations will adopt the sanitary survey as a tool for identifying factors that affect drinking water sources, which is essential for drinking water safety.
What factors affect sustained adoption of safe water, hygiene and sanitation technologies?A systematic review of literature, June 2015. EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.
Authors: Kristyna Hulland, Nina Martin, Robert Dreibelbis, Julia DeBruicker Valliant, Peter Winch
Among the exciting advances in water, sanitation, and hygiene (WASH) programmes and policies, sustainability counts as a renewed and crucial area of focus for implementers, scientists, policy makers, and donors alike. To further our understanding of the barriers and facilitators to sustained adoption and use of water and sanitation technologies, we conducted a systematic review of studies concerning both initial and sustained adoption of WASH interventions at the individual, household and community levels in low- and middleincome countries. We built on previous reviews of handwashing and point-of-use water treatment, with a comprehensive review that is dramatically larger and broader in scope than previous studies. It is the only review we know of that includes a range of WASH interventions and factors associated with adoption.
Fecal Coliform Contamination of Drinking Water: An Evaluation of World Field Assessment Techniques. EWB-USA Technical Paper 104.
Authors: William Fripp, Catherine Dane Woodyard, PhD, and Marina Hanna
A safe, consistent, and reliable water supply is a universal need. However, a large number of the world’s population lives in areas that are suffering from water quality problems and water shortages. Many areas have contaminated water with fecal coliform bacteria as the primary contaminant of concern. As a result, there are many aid groups that are actively working to develop and improve the water supply in the developing world.
An important first step in such work is an accurate appraisal of the existing water supply. This appraisal often requires a rapid, onsite field assessment of possible fecal coliform contamination with minimal equipment. This paper summarizes a qualitative evaluation of five field assessment techniques undertaken by an interdisciplinary team of students involved in aid work. The focus of this evaluation is on Presence/Absence testing.
The evaluation examines usability, accuracy, cost, speed of results, and ease of explaining results to the local population. Advantages and disadvantages of each technique have been identified and discussed. The purpose of this paper is to provide guidance that will aid in the selection of a suitable rapid fecal coliform field test. The team performed their assessments of the five techniques in the United States under controlled situations, as well as during an evaluation trip to Belize.
All of the evaluations were conducted under the oversight of a professional engineer with experience in water quality assessments and water treatment design. This study and paper is of value to aid groups involved in the assessment of water projects in the developing world.
Household Water Quantity and Health: A Systematic Review. Int. J. Environ. Res. Public Health 2015, 12(6), 5954-5974
Authors: Rachel D. Stelmach and Thomas Clasen
While the quantity of water used in the home is thought to be an important determinant of health, much of the evidence relies on using water access as a proxy for quantity. This review examines the health effects of household water quantity using studies that directly measured water quantity.
We searched MEDLINE, EMBASE, the Cochrane Library, Web of Science, and article reference lists. Eligible studies included experimental and observational studies that measured a difference in water quantity and quantified an association between water quantity and health outcomes. 21 studies, divided into six of the many possible water-quantity associated outcomes, met the eligibility criteria. Due to heterogeneity in designs, settings, methods, and outcomes, a meta-analysis was inappropriate.
Overall results showed a positive association between water quantity and health outcomes, but the effect depended on how the water was used. Increased water usage for personal hygiene was generally associated with improved trachoma outcomes, while increased water consumption was generally associated with reduced gastrointestinal infection and diarrheal disease and improved growth outcomes.
In high-income countries, increased water consumption was associated with higher rates of renal cell carcinoma and bladder cancer but not associated with type II diabetes, cardiac-related mortality, or all-cause mortality.
USAID WASH and Nutrition Webinar, May 2015
USAID’s Elizabeth Jordan and Katherine Dennison discuss the connection between undernutrition and lack of access to water, sanitation and hygiene (WASH) services and highlight opportunities for integrated programming to achieve better health outcomes.
E. coli from dishcloths as an indicator of hygienic status in households. Journal of Water, Sanitation and Hygiene for Development In Press, 2015 | doi:10.2166/washdev.2015.119
Authors: V. Keshav, A. Mathee, N. Naicker, A. Swart and T. G. Barnard
E. coli is routinely used as an indicator of fecal pollution although some strains are capable of causing diarrhea. E. coli was used as a model organism for this study to assess the possibility that dishcloths used in households could contribute to the occurrence of diarrhea. Dishcloths (n = 424) were collected from five suburbs in Johannesburg (South Africa) as part of a larger Health, Environment & Development (HEAD) study. Results for the total coliforms indicated that on average 81% of the samples analyzed had total coliform counts of more than 1,000 cfu/100 ml per 25 cm2 cloth.
The E. coli results indicated that 40% of the samples had culturable E. coli present with 17% of the samples showing the presence of >1,000 cfu/100 ml per 25 cm2 cloth. Except for the samples from Bertrams all the pathogenic E. coli genes could be detected in various combinations in the different samples. Since all the diarrheagenic E. coli strains detected can be accepted as culturable due to the enrichment step, there is a clear danger of contamination of food and surfaces exposed to the contaminated dishcloths. The results indicated that there is a need for public education regarding hygiene in the households, especially if the same dishcloth is used for various tasks.
Effect of common rooftop materials as support base for solar disinfection (SODIS) in rural areas under temperate climates
Effect of common rooftop materials as support base for solar disinfection (SODIS) in rural areas under temperate climates. Solar Energy, May 2015.
Authors: M. Vivaa, M. Fuentes, J. Castro, R. García-Pacheco
- Metal roofing and bamboo vegetable cover were studied as support materials for SODIS.
- Metal covers enhance SODIS due to high reflectivity & heat transfer properties.
- Maximum water temperatures differences in the bottles were of about 2.5 °C.
- SODIS processes starting at midday achieved faster inactivation.
Two common rooftop materials easily found in rural areas – zinc-coated metal sheet and bamboo cover – were studied to analyse their possible influence in the solar disinfection process by affecting the received UV radiation and water temperature in SODIS plastic bottles. The objective is to use available local materials to enhance the process while reducing the extra energy usage required for the manufacturing of new ad-hoc systems.
Experiments were conducted at a temperate climate, 40 °N latitude, over different seasons of the year. Escherichia coli and total coliforms disinfection processes were studied. Results show that in most cases the bottles over the zinc-coated metal roofing material reached an inactivation level of 1-log higher than those on the bamboo cover. Maximum water temperatures differences in the bottles over the two materials were of about 2.5 °C in the best case. Higher inactivation in the zinc-coated metal sheet when water temperature is below 40 °C should be attributed to better material reflectivity. At water temperatures around 40 °C, the 2.5 °C difference can be significative and accelerate the disinfection process.
Material heat transfer characteristics have been also found to be essential, especially when the solar disinfection starts at mid-day instead of early in the morning. In this case, as the support materials are already at higher temperatures because of solar irradiance absorption, the water temperature in the bottles increases more rapidly, contributing to the water disinfection process when it rises above 40 °C.
Eliminating Diseases by Investing in WASH. Huffington Blog, May 2015.
Author: Neeraj Mistry, anaging Director for the Global Network for Neglected Tropical Diseases.
At the turn of the century, world leaders came together at the United Nations in New York to develop the Millennium Development Goals (MDGs), a set of eight ambitious goals and targets meant to significantly reduce poverty by the year 2015. As the window to achieve these goals closes this year, we reflect on progresses made and look ahead to the sustainable development goals (SDGs) that will shape the development agenda for the next 15 years.
A number of MDG targets have already been met, including efforts to reduce cases of HIV/AIDS, malaria and other diseases (MDG 6) and improving access to safe drinking water (MDG 7). Moving forward, addressing neglected tropical diseases (NTDs) will be a critical component when working toward meeting both of these goals. NTDs are bacterial, parasitic and viral infections that affect the most marginalized communities across the world and are often the result of inadequate water supply, limited access to sanitation facilities and poor hygiene. Areas with stagnant water are breeding grounds for insects that carry NTDs, notably mosquitoes which transmit malaria, but also dengue fever, lymphatic filariasis and chikungunya. By promoting integrated vector management and improved water control measures in endemic countries, we can simultaneously work to combat HIV/AIDS and malaria, while also working to control and eliminate NTDs.
Since 2000, there has been significant advancement in the fight against HIV/AIDS, particularly by increasing access to life-saving antiretroviral therapy (ART) for people living with HIV. The United Nations estimates that ART has saved 6.6 million livessince 1995. As with malaria, there are additional opportunities for integration that not only have the potential to reduce rates of HIV infection but also significantly improve water, sanitation and hygiene (WASH) conditions. For example, in many developing countries, women remain disproportionately vulnerable to HIV infection due to greater social safety issues, such as lacking access to safe and accessible latrines. By not having access to a safe lavatory, women are forced to use public spaces to openly defecate and manage their menstrual needs, making them increasingly susceptible to infections as well as sexual violence. Globally, more than two billion people lack access to a proper toilet. Many common, poor hygiene practices, such as open defecation and failure to wash one’s hands, promote the spread of disease. These factors combined perpetuate the cycle of NTD infections and other serious infections.
The proposed SDGs currently consist of 17 goals with 169 targets that aim to end poverty and hunger, improve health and education, make cities more sustainable, combat climate change, and protect oceans and forests. Goal 3 encompasses a number of health-related objectives and targets, including ending the epidemics of AIDS, tuberculosis, malaria, NTDs and water-borne diseases by 2030. Meeting these targets will go hand-in-hand with Goal 6 — achieving access to adequate and equitable sanitation and hygiene for all, ending open defecation, and paying special attention to the needs of women and girls and those in vulnerable situations.
There are many ways that enhancing WASH conditions unswervingly leads to NTD control and elimination. For example, by improving access and quality of water, sanitation and hygiene, we can significantly reduce the number of people suffering from trachoma, an infectious eye disease and leading cause of preventable blindness, which results from limited access to clean water and proper sanitation. By simply providing access to clean water, we can reduce the number of trachoma cases by 27 percent. Similarly, having better sanitation in place can decrease cases of schistosomiasis, a parasitic disease carried by fresh water snails infected with parasites. Women are especially vulnerable, given that cases of female genital schistosomiasis (FGS) result in three times greater chances of contracting HIV. It is estimated that at least 16 million women may be infected with FGS in Africa.
It is evident that WASH interventions have a multiplier effect and positively impact other health issues and development goals. As the window to achieve the MDGs comes to a close this year and we grow closer to confirming the goals and targets that will shape the next 15 years, we must emphasize the important synergies between WASH and the control and elimination of NTDs.
This blog post is part of the “WASH and the MDGs: The Ripple Effect” blog series, in partnership with WASH Advocates, addressing the importance of water, sanitation and hygiene (WASH) to global development. To see all the other posts in the series, click here. To learn more about WASH, visit the WASH Advocates website, and for more information about the Millennium Development Goals, click here.
Handwashing before drawing water: a sixth critical time? Waterlines, Apr 2015.
Author: Sally Sutton
The promotion of critical times for handwashing has done much to improve knowledge on hygiene, even if rather less on the practice. However while there has long been a recognition of the need to wash hands before preparing food, there has never been any mention of taking the same precautions before drawing water.
With almost half of rural Africa still taking water either by bucket and rope or by scooping water from surface and shallow ground water, lack of handwashing can not only lead to contamination of the water being carried home, but also of the source itself, as demonstrated by source water quality monitoring detailed in this paper.
Even for those taking water from better protected sources, dirty hands can lead to contamination of collected water, especially where bowls and buckets are the main vessels for water transport. Handwashing before water collection is proposed as an additional barrier to faecal-oral contamination, to make a sixth critical time.
Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis
Association of Supply Type with Fecal Contamination of Source Water and Household Stored Drinking Water in Developing Countries: A Bivariate Meta-analysis. Env Health Perspec, May 2015.
Authors: Katherine F. Shields, Robert E.S. Bain, Ryan Cronk, Jim A. Wright, and Jamie Bartram
Background: Access to safe drinking water is essential for health. Monitoring access to drinking water focuses on water supply type at the source, but there is limited evidence on whether quality differences at the source persist in water stored in the household.
Objectives: To assess the extent of fecal contamination at the source and in household storedwater (HSW) and explore the relationship between contamination at each of these sampling points and water supply type.
Methods: A bivariate random-effects meta-analysis of 45 studies, identified through asystematic review, that reported either the proportion of samples free of fecal indicator bacteria and/or individual sample bacteria counts for source and HSW, disaggregated by supply type.
Results: Water quality deteriorated substantially between source and stored water. Mean percentage of contaminated samples (noncompliance) at the source was 46% (95% CI: 33, 60%) while mean noncompliance in HSW was 75% (95% CI: 64, 84%). Water supply type was significantly associated with noncompliance at the source (p < .001) and in HSW (p = 0.03). Source water (OR = 0.2; 95% CI: 0.1, 0.5) and HSW (OR = 0.3; 95% CI: 0.2, 0.8) from pipedsupplies had significantly lower odds of contamination when compared to non-piped water,potentially due to residual chlorine.
Conclusions: Piped water is less likely to be contaminated compared to other water supply typesat both the source and in HSW. A focus on upgrading water services to piped supplies may helpimprove safety, including for those drinking stored water.
Accuracy, precision, usability, and cost of free chlorine residual testing methods. Journal of Water and Health Vol 13 No 1 pp 79–90 © IWA Publishing 2015 doi:10.2166/wh.2014.195.
Authors: Anna Murray and Daniele Lantagne
Chlorine is the most widely used disinfectant worldwide, partially because residual protection is maintained after treatment. This residual is measured using colorimetric test kits varying in accuracy, precision, training required, and cost. Seven commercially available colorimeters, color wheel and test tube comparator kits, pool test kits, and test strips were evaluated for use in low-resource settings by: (1) measuring in quintuplicate 11 samples from 0.0–4.0 mg/L free chlorine residual in laboratory and natural light settings to determine accuracy and precision; (2) conducting volunteer testing where participants used and evaluated each test kit; and (3) comparing costs.
Laboratory accuracy ranged from 5.1–40.5% measurement error, with colorimeters the most accurate and test strip methods the least. Variation between laboratory and natural light readings occurred with one test strip method. Volunteer participants found test strip methods easiest and color wheel methods most difficult, and were most confident in the colorimeter and least confident in test strip methods. Costs range from 3.50–444 USD for 100 tests. Application of a decision matrix found colorimeters and test tube comparator kits were most appropriate for use in low-resource settings; it is recommended users apply the decision matrix themselves, as the appropriate kit might vary by context.
Microbial quality of domestic water: following the contamination chain in a rural township in Kenya. Journal of Water, Sanitation and Hygiene for Development Vol 5 No 1 pp 39–49 © IWA Publishing 2015 doi:10.2166/washdev.2014.070
Authors: Pauline W. Macharia, Paul T. Yillia, Wairimu A. Muia, Denis Byamukama and Norbert Kreuzinger
A study was undertaken in Njoro Township, Kenya to evaluate the extent to which drinking water was subjected to post-collection faecal contamination in low-income and high-income households. Boreholes were the main drinking water sources, accounting for roughly 70% singular access. The microbial quality of drinking water from the boreholes deteriorated from the point-of-collection through conveying containers of small-scale water vendors to household storage containers, irrespective of their income status.
The densities of Escherichia coli (EC) were relatively low at the point-of-collection – median (M): 18 CFU/100 mL, range (R): 0–220, n = 60 – increasing considerably in the containers of water vendors (M: 290 CFU/100 mL, R: 30–350) and slightly (M: 360 CFU/100 mL, R: 0–520) between vendors and low-income households, many of whom used the services of vendors unlike high-income households who relied on a piped system on premises (M: 40 CFU/100 mL, R: 0–500). Post-collection contamination was high in low-income households compared to high-income households but differences were not significant between the two household categories with and without household water treatment (HWT).
Different HWT methods in the two household categories significantly reduced faecal contamination, but unhygienic handling and poor storage practices afterwards caused recontamination. HWT and behavioural change measures need not selectively target household groups solely on the basis of their income status.
Development of improved low-cost ceramic water filters for viral removal in the Haitian context. Journal of Water, Sanitation and Hygiene for Development Vol 5 No 1 pp 28–38 © IWA Publishing 2015 doi:10.2166/washdev.2014.121.
Authors: L. Guerrero-Latorre, M. Rusiñol, A. Hundesa, M. Garcia-Valles, S. Martinez, O. Joseph, S. Bofill-Mas and R. Girones
Household-based water treatment (HWT) is increasingly being promoted to improve water quality and, therefore, health status in low-income countries. Ceramic water filters (CWFs) are used in many regions as sustainable HWT and have been proven to meet World Health Organization (WHO) microbiological performance targets for bacterial removal (2–4 log); however, the described viral removal efficiencies are insufficient to significantly reduce the associated risk of viral infection. With the objective of improving the viral removal efficiencies of ceramic water filters, new prototypes with different oxide compositions and firing atmospheres have been developed and evaluated.
For removal efficiencies human adenoviruses, MS2 bacteriophage and Escherichia coli were quantified in all prototypes. A new model of CWF that was fired in a reductive atmosphere presented virus and bacteria removal efficiencies greater than 3.0 log and 2.5 log, respectively, which would fulfill the viral targets that are recommended by the WHO. Ceramic characterization of the selected filters, which were fired in a reductive atmosphere, showed that a larger specific surface area than those of control filters and higher fraction of a positive Z-potential fraction are the most likely explanations for this increase in virus removal.