Comparison of different solar reactors for household disinfection of drinking water in developing countries

October 8, 2012 · 0 comments

Comparison of different solar reactors for household disinfection of drinking water in developing countries: evaluation of their efficacy in relation to the waterborne enteropathogen Cryptosporidium parvum. Transactions of the Royal Society of Tropical Medicine and Hygiene, Sept 2012.

H. Gómez-Cousoa, et al.

Solar water disinfection (SODIS) is a type of treatment that can significantly improve the microbiological quality of drinking water at household level and therefore prevent waterborne diseases in developing countries. Cryptosporidium parvum is an obligate protozoan parasite responsible for the diarrhoeal disease cryptosporidiosis in humans and animals. Recently, this parasite has been selected by the WHO as a reference pathogen for protozoan parasites in the evaluation of household water treatment options.

In this study, the field efficacy of different static solar reactors [1.5 l transparent plastic polyethylene terephthalate (PET) bottles as well as 2.5 l borosilicate glass and 25 l methacrylate reactors fitted with compound parabolic concentrators (CPC)] for solar disinfection of turbid waters experimentally contaminated with C. parvum oocysts was compared. Potential oocyst viability was determined by inclusion/exclusion of the fluorogenic vital dye propidium iodide.

The results demonstrate that static solar reactors fitted with CPCs are an excellent alternative to the conventional SODIS method with PET bottles. These reactors improved the efficacy of the SODIS method by enabling larger volumes of water to be treated and, in some cases, the C. parvum oocysts were rendered totally unviable, minimising the negative effects of turbidity.

Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant

October 8, 2012 · 0 comments

Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device. International Journal of Hygiene and Environmental Health, Aug 2012.

Angela D. Coulliette ∗, Kyle S. Enger, Mark H. Weir, Joan B. Rose. Michigan State University, Department of Fisheries and Wildlife, East Lansing, MI 48824, United States

Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively. Household water treatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction.

When one infected individual was contributing to the water contamination through fecal material leaking into the water source, the risk of disease associated with drinking untreated water was high according to a Monte Carlo analysis. If water was treated, risk greatly decreased for typhoid fever and a median of 3.5 for cholera. Insights on risk management policies and strategies for public health workers were gained using a simple QMRA scenario informed by laboratory assessment of HWT.

Microbiological effectiveness of mineral pot filters in Cambodia

October 5, 2012 · 0 comments

Microbiological effectiveness of mineral pot filters in Cambodia. Environ. Sci. Technol., DOI: 10.1021/es3027852. Publication Date (Web): October 3, 2012.

Joseph Brown , Ratana Chai , Alice Wang , and Mark Sobsey

Mineral Pot Filters (MPFs) are household water treatment (HWT) devices that are manufactured and distributed by the private sector, with millions of users in Southeast Asia. Their effectiveness in reducing waterborne microbes has not been previously investigated. We purchased three types of MPFs available on the Cambodian market for systematic evaluation of bacteria, virus, and protozoan surrogate microbial reduction in laboratory challenge experiments following WHO recommended performance testing protocols.

Results over the total 1500 liter testing period per filter indicate that the devices tested were highly effective in reducing Esherichia coli (99.99%+), moderately effective in reducing bacteriophage MS2 (99%+), and somewhat effective against Bacillus atrophaeus, a spore-forming bacterium we used as a surrogate for protozoa (88%+). Treatment mechanisms for all filters included porous ceramic and activated carbon filtration.

Our results suggest that these commercially available filters may be at least as effective against waterborne pathogens as other, locally available treatment options such as ceramic pot filters or boiling. More research is needed on the role these devices may play as interim solutions to the problem of unsafe drinking water in Cambodia and globally.

Daniele Lantagne discusses sustainable water treatment implementation

October 5, 2012 · 0 comments

Daniele Lantagne discusses sustainable water treatment implementation | Source: Heather Wax, Tufts School of Engineering – Sept 28, 2012.

In the world today, there are roughly 800 million people who don’t have access to an “improved” water source, like a piped system or protected well, designed to shield the water from microbiological contamination. Hundreds of millions more drink unsafe water even though it comes from a source that is improved. If the water coming from their rivers, springs, or ground is contaminated, and the region lacks the infrastructure needed to provide clean water, what is the alternative? One short-term solution is to treat the water at home.

There are a variety of ways water can be treated at the household level: There are simple systems, like chlorination or locally made ceramic filters, and there are more complex systems that remove a greater number of the organisms that cause diarrheal disease, but they are also more expensive and harder to use and transport. When resources are limited, is it more impactful to help a few people a lot, or a lot of people a little less? Is it more effective to implement a high-end system that requires significant training and follow-up, or a simpler solution that requires less investment and maintenance, but only removes some of the organisms that cause diarrheal disease? These are the types of questions Daniele Lantagne finds fascinating.

Assistant Professor Daniele Lantagne specializes in developing, implementing, and evaluating household water treatment projects in developing countries and areas of emergency.

Daniele Lantagne, an assistant professor in the Department of Civil and Environmental Engineering, specializes in developing, implementing, and evaluating household water treatment projects in developing countries and areas of emergency. She has applied her knowledge to diverse applications—including engineering design work, helping to make water treatment products more approachable and easier to use, as well as laboratory research looking at how variations in manufacturing and clay can determine the effectiveness of ceramic filters or the dosage of chlorine needed to appropriately treat water. In 2011, she served as the water and sanitation expert on a United Nations panel investigating the origin of the cholera epidemic in Haiti, where she has worked on water projects since 2000. But most of all, she is interested in implementation-based research.

Lantagne travels to places like East Africa, Asia, and Central and South America to conduct field evaluations and surveys, and to watch how, and if, the people who have received a household treatment product are using it to effectively improve their drinking water quality. “Effective use has a whole host of inputs,” she says. “Were they trained effectively? Are they using the product? Do they want to use it? Are they using it every day?”

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Diarrhea and dengue control in rural primary schools in Colombia

October 5, 2012 · 1 comment

Trials. 2012 Oct 3;13(1):182.

Diarrhea and dengue control in rural primary schools in Colombia: study protocol for a randomized controlled trial.

Overgaard HJ, Alexander N, Matis MI, Jaramillo JF, Olano VA, Vargas SL, Sarmiento DM, Lenhart A, Seidu R, Stenström TA.

BACKGROUND: Diarrheal diseases and dengue fever are major global health problems. Where provision of clean water is inadequate, water storage is crucial. Fecal contamination of stored water is a common source of diarrheal illness, but stored water also provides breeding sites for dengue vector mosquitoes. Poor household water management and sanitation are therefore potential determinants of both diseases. Little is known of the role of stored water for the combined risk of diarrhea and dengue, yet a joint role would be important for developing integrated control and management efforts.

Even less is known of the effect of integrating control of these diseases in school settings. The objective of this trial was to investigate whether interventions against diarrhea and dengue will significantly reduce diarrheal disease and dengue entomological risk factors in rural primary schools.

Methods/design: This is a 2×2 factorial cluster randomized controlled trial. Eligible schools were rural primary schools in La Mesa and Anapoima municipalities, Cundinamarca, Colombia. Eligible pupils were school children in grades 0 to 5. Schools were randomized to one of four study arms: diarrhea interventions (DIA); dengue interventions (DEN); combined diarrhea and dengue interventions (DIADEN); and control (C).

Schools were allocated publicly in each municipality (strata) at the start of the trial, obviating the need for allocation concealment. The primary outcome for diarrhea is incidence rate of diarrhea in school children and for dengue it is density of adult female Aedes aegypti per school. Approximately 800 pupils from 34 schools were enrolled in the trial with eight schools in the DIA arm, nine in the DEN, eight in the DIADEN, and nine in the control arms.

The trial status as of June 2012 was: completed baseline data collections; enrollment, randomization, and allocation of schools. The trial was funded by the Research Council of Norway and the Lazos de Calandaima Foundation.

DISCUSSION: This is the first trial investigating the effect of a set of integrated interventions to control both dengue and diarrhea. This is also the first trial to study the combination of diarrhea-dengue disease control in school settings.

Trial registration Current Controlled Trials ISRCTN40195031.

Scientists develop low cost, pocket friendly and re-usable water purifier

October 4, 2012 · 0 comments

Amity scientists develop low cost, pocket friendly and re-usable water purifier using Silver Nano p | Source: NewsTrackIndia, Oct 4, 2012.

NOIDA (U.P.), Oct.4 (ANI): Amity scientists have developed a low cost, pocket friendly and re-usable water purifier using Silver Nano particles.

Dr. V K Jain, Director, AIARS and Dr. Suman Nagpal- Assistant Professor, AIARS, have created ripples in the world of science by developing a re-usable, economic and easy to carry first of its kind water purifier based on silver nano embedded porous concrete pebbles.

The present product in the form of a small portable tea bag is likely to be priced at an unimaginably low cost (most probably as low as Rs. 100) as compared to other products in the segment.

The eco-friendly purifier provides around 99 % decontamination of microbial load in the treated water. The device has very good reusability and its efficacy remains the same even after 120-125 uses of the same pebbles within a time span of 6 months.

The purifier can inhibit the growth of bacteria faster than conventional filters without consuming any energy/voltage or current. It can be reused to cleanse nearly 1000 liters of water in a time span of six months. No such other device exists across the world at such a low cost.

The portability, low cost and simplicity of the proposed system makes it usable for all be it the people in remote areas and high altitudes especially by Armed Forces Personnel who are stationed at high altitudes and directly drink water from rivers or melting ice and don’t have any device (UV/ electricity source) for purification of water. The purifier can also substitute bottled water in India.

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The chain of infection transmission in the home and everyday life settings, and the role of hygiene

October 4, 2012 · 0 comments

The chain of infection transmission in the home and everyday life settings, and the role of hygiene in reducing the risk of infection, 2012.

SF Bloomfield; M Exner; KJ Nath; C Signorelli; EA Scott. IFH Forum on Home Hygiene.

The evidence presented in the 2009 IFH review on the global burden of hygiene-related diseases shows that infection outbreaks in the domestic home and everyday life settings, particularly gastrointestinal (GI) infections (also called infectious intestinal disease (IID)), respiratory infections (RT), and skin, wound and eye infections, continue to exact a heavy toll on the health and prosperity of the global community. The evidence indicates that a significant proportion of these infections are preventable by getting people to practice better hygiene in their own homes and in everyday life. This includes food and respiratory hygiene, and better hand, surface and laundry hygiene practices coupled with other practices such as safe disposal of refuse and wastewater. In communities that lack access to adequate sanitation and clean water, this may also involve ensuring water treatment and safe storage and the safe disposal of faeces.

Evaluating the Sustained Health Impact of Household Chlorination of Drinking Water in Rural Haiti.

October 3, 2012 · 0 comments

Am J Trop Med Hyg. 2012 Sep 17.

Evaluating the Sustained Health Impact of Household Chlorination of Drinking Water in Rural Haiti.

Harshfield E, Lantagne D, Turbes A, Null C.

The Jolivert Safe Water for Families program has sold sodium hypochlorite solution (chlorine) and conducted household visits in rural Haiti since 2002. To assess the impact of the program on diarrheal disease, in 2010 we conducted a survey and water quality testing in 201 program participants and 425 control households selected at random. Fifty-six percent of participants (versus 10% of controls) had free chlorine residuals between 0.2 and 2.0 mg/L, indicating correct water treatment.

Using intention-to-treat analysis, we found that significantly fewer children in participant households had an episode of diarrhea in the previous 48 hours (31% versus 52%; P = 0.001) with 59% reduced odds (odds ratio = 0.41, 95% confidence interval = 0.21-0.79). Treatment-on-treated estimates of the odds of diarrhea indicated larger program effects for participants who met more stringent verifications of participation.

Diarrheal disease reduction in this long-term program was comparable with that seen in short-term randomized, controlled interventions, suggesting that household chlorination can be an effective long-term water treatment strategy.

The Life of a Plastic Water Bottle

October 3, 2012 · 0 comments

The Life of a Plastic Water Bottle | Peter S. Green, Bloomberg – Oct 2, 2012

Solar Lights
Social entrepreneur Illac Diaz hopes to brighten a million Filipino poor with his “solar light bulbs” — water-filled bottles embedded in corrugated roofing. The bottles refract sunlight, lighting the living space below.

Inmates and guards manufacture the "bulbs" in a Manila prison.

PET is easily recycled and shouldn’t be left to pile up in dumps and on the ocean floor, says Paul Gardner, executive director of Recycling Reinvented, a group promoting profitable recycling programs that’s partially funded by Nestle.

Point-of-collection chlorine dispenser system in Kenya

September 26, 2012 · 1 comment

Social Engineering: Evidence from a Suite of Take-up Experiments in Kenya, 2011. (DRAFT)

Michael Kremer, et al.

Many effective health products and behaviors available through the private market are not widely adopted in less developed countries. For example, fewer than 10% of households in our Kenyan study area treat their water with dilute chlorine. Using a suite of randomized evaluations, we find that information and marketing interventions do little to boost use of chlorine. However, chlorine take-up is highly sensitive to price, convenience and social context, with more than half of households using chlorine when an individually-packaged supply is delivered free to the home.

The highest sustained takeup is achieved by combining free, convenient, salient, and public access through a point-of-collection chlorine dispenser system and a local promoter. More than half of households treat their water and this use continues 30 months later even though promoters are paid only for the first six months. The estimated long-run costs of this intervention at scale, including administrative costs, are between $.25 and $.50 per person per year.

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