Bibliography of 2012 HWTS Studies by Mark Sobsey

July 25, 2012 · 0 comments

This is an annotated bibliography of 2012 HWTS studies authored or co-authored by Mark Sobsey so far in 2012. This bibliography will be updated on a periodic basis.

1. Am J Trop Med Hyg. 2012 Jul 23.

Boiling as Household Water Treatment in Cambodia: A Longitudinal Study of Boiling Practice and Microbiological Effectiveness.

Brown J, Sobsey MD.

Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom; Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.

This paper focuses on the consistency of use and microbiological effectiveness of boiling as it is practiced in rural Cambodia. We followed 60 randomly selected households in Kandal Province over 6 months to collect longitudinal data on water boiling practices and effectiveness in reducing Escherichia coli in household drinking water. Despite > 90% of households reporting that they used boiling as a means of drinking water treatment, an average of only 31% of households had boiled water on hand at follow-up visits, suggesting that actual use may be lower than self-reported use. We collected 369 matched untreated and boiled water samples. Mean reduction of E. coli was 98.5%; 162 samples (44%) of boiled samples were free of E. coli (< 1 colony-forming unit [cfu]/100 mL), and 270 samples (73%) had < 10 cfu/100 mL. Storing boiled water in a covered container was associated with safer product water than storage in an uncovered container.

2. Am J Trop Med Hyg. 2012 Jun;86(6):913-21.

A Randomized Controlled Trial of the Plastic-Housing BioSand Filter and Its Impact on Diarrheal Disease in Copan, Honduras.

Fabiszewski de Aceituno AM, Stauber CE, Walters AR, Meza Sanchez RE, Sobsey MD.

Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina; Institute of Public Health, Georgia State University, Atlanta, Georgia; Triple
Quest, Tegucigalpa, MDC, Honduras.

Point of use drinking water treatment with the BioSand filter (BSF) allows people to treat their water in the home. The purpose of this research was to document the ability of the Hydraid plastic-housing BSF to reduce diarrheal disease in households who received a BSF in a randomized controlled trial. The trial of the Hydraid plastic-housing BSF was carried out in rural, mountainous communities in Copan, Honduras during April of 2008 to February of 2009. A logistic regression adjusting for clustering showed that the incidence of diarrheal disease in children under 5 years was reduced by approximately 45% (odds ratio = 0.55, 95% confidence interval = 0.28, 1.10) in households that had a BSF compared with those households without a BSF, but this finding fluctuated depending on season and was not statistically significant. Households with a BSF had significantly better drinking water quality regardless of water source or season.

3. J Water Health. 2012 Jun;10(2):209-20.

A post-implementation evaluation of ceramic water filters distributed to tsunami-affected communities in Sri Lanka.

Casanova LM, Walters A, Naghawatte A, Sobsey MD.

Institute of Public Health, Georgia State University, P.O. Box 3995, Atlanta GA 30302, USA E-mail:

Sri Lanka was devastated by the 2004 Indian Ocean tsunami. During recovery, the Red Cross distributed approximately 12,000 free ceramic water filters. This cross-sectional study was an independent post-implementation assessment of 452 households that received filters, to determine the proportion still using filters, household characteristics associated with use, and quality of household drinking water. The proportion of continued users was high (76%). The most common household water sources were taps or shallow wells. The majority (82%) of users used filtered water for drinking only. Mean filter flow rate was 1.12 L/hr (0.80 L/hr for households with taps and 0.71 for those with wells). Water quality varied by source; households using tap water had source water of high microbial quality. Filters improved water quality, reducing Escherichia coli for households (largely well users) with high levels in their source water. Households were satisfied with filters and are potentially long-term users. To promote sustained use, recovery filter distribution efforts should try to identify households at greatest long-term risk, particularly those who have not moved to safer water sources during recovery. They should be joined with long-term commitment to building supply chains and local production capacity to ensure safe water access.

4. Environ Sci Technol. 2012 Jan 17;46(2):722-8.

Cluster randomized controlled trial of the plastic BioSand Water filter in Cambodia.

Stauber CE, Printy ER, McCarty FA, Liang KR, Sobsey MD.

Institute of Public Health, Georgia State University, P.O. Box 3995, Atlanta, Georgia 30302-3995, United States.

About half of the rural population of Cambodia lacks access to improved water; an even higher percentage lacks access to latrines. More than 35,000 concrete BioSand Water filters (BSF) have been installed in the country. However, the concrete BSF takes time to produce and weighs hundreds of pounds. A plastic BSF has been developed but may not perform to the same benchmarks established by its predecessor. To evaluate plastic BSF performance and health impact, we performed a cluster randomized controlled trial in 13 communities including 189 households and 1147 participants in the Angk Snoul district of Kandal Province from May to December 2008.

The results suggest that villages with plastic BSFs had significantly lower concentrations of E. coli in drinking water and lower diarrheal disease (incidence rate ratio 0.41, 95% confidence interval: 0.24-0.69) compared to control villages. As one of the first studies on the plastic BSF in Cambodia, these are important findings, especially in a setting where the
concrete BSF has seen high rates of continued use years after installation. The study suggests the plastic BSF may play an important role in scaling up the distribution/implementation of the BSF, potentially improving water quality and
health in the region.

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