Science Current Events | Science News | Brightsurf.com
 

Sunlight plus lime juice makes drinking water safer

April 18, 2012
Looking for an inexpensive and effective way to quickly improve the quality of your drinking water? According to a team of researchers from the Johns Hopkins Bloomberg School of Public Health and the Johns Hopkins School of Medicine, sunlight and a twist of lime might do the trick. Researchers found that adding lime juice to water that is treated with a solar disinfection method removed detectable levels of harmful bacteria such as Escherichia coli (E. coli) significantly faster than solar disinfection alone. The results are featured in the April 2012 issue of American Journal of Tropical Medicine and Hygiene.

"For many countries, access to clean drinking water is still a major concern. Previous studies estimate that globally, half of all hospital beds are occupied by people suffering from a water-related illness," said Kellogg Schwab, PhD, MS, senior author of the study, director of the Johns Hopkins University Global Water Program and a professor with the Bloomberg School's Department of Environmental Health Sciences. "The preliminary results of this study show solar disinfection of water combined with citrus could be effective at greatly reducing E. coli levels in just 30 minutes, a treatment time on par with boiling and other household water treatment methods. In addition, the 30 milliliters of juice per 2 liters of water amounts to about one-half Persian lime per bottle, a quantity that will likely not be prohibitively expensive or create an unpleasant flavor."

In low-income regions, solar disinfection of water is one of several household water treatment methods to effectively reduce the incidence of diarrheal illness. One method of using sunlight to disinfect water that is recommended by the United Nations Children's Fund (UNICEF) is known as SODIS (Solar water Disinfection). The SODIS method requires filling 1 or 2 L polyethylene terephthalate (PET plastic) bottles with water and then exposing them to sunlight for at least 6 hours. In cloudy weather, longer exposure times of up to 48 hours may be necessary to achieve adequate disinfection. To determine if one of the active constituents in limes known as psoralenes could enhance solar disinfection of water, Schwab and Alexander Harding, lead author of the study and a medical student at the Johns Hopkins School of Medicine, looked at microbial reductions after exposure to both sunlight and simulated sunlight. The researchers filled PET plastic bottles with dechlorinated tap water and then added lime juice, lime slurry, or synthetic psoralen and either E. coli, MS2 bacteriophage or murine norovirus. Researchers found that lower levels of both E. coli and MS2 bacteriophage were statistically significant following solar disinfection when either lime juice or lime slurry was added to the water compared to solar disinfection alone. They did find however, that noroviruses were not dramatically reduced using this technique, indicating it is not a perfect solution.

"Many cultures already practice treatment with citrus juice, perhaps indicating that this treatment method will be more appealing to potential SODIS users than other additives such as TiO2 [titanium dioxide] or H2O2[hydrogen peroxide]," suggest the authors of the study. However, they caution, "additional research should be done to evaluate the use of lemon or other acidic fruits, as Persian limes may be difficult to obtain in certain regions."

Johns Hopkins University Bloomberg School of Public Health


Related Disinfection Current Events and Disinfection News Articles


Programming DNA to reverse antibiotic resistance in bacteria
At its annual assembly in Geneva last week, the World Health Organization approved a radical and far-reaching plan to slow the rapid, extensive spread of antibiotic resistance around the world.

Phage spread antibiotic resistance
Investigators found that nearly half of the 50 chicken meat samples purchased from supermarkets, street markets, and butchers in Austria contained viruses that are capable of transferring antibiotic resistance genes from one bacterium to another--or from one species to another.

Household pets can transmit infections to people
Household pets can transmit infection to people, especially those with weak immune systems, young children, pregnant women and seniors, according to an article in CMAJ (Canadian Medical Association Journal).

New study suggests ways to avoid catching diseases from pets
As new medical diagnostics become available, researchers are increasingly discovering situations in which pets can transmit diseases to humans--especially when an owner's immune system is compromised.

UV light robot to clean hospital rooms could help stop spread of 'superbugs'
Can a robot clean a hospital room just as well as a person? According to new research out of the Texas A&M Health Science Center College of Medicine, that is indeed the case. Chetan Jinadatha, M.D., M.P.H., assistant professor at the Texas A&M College of Medicine and chief of infectious diseases at the Central Texas Veterans Health Care System in Temple, is studying the effectiveness of a germ-zapping robot to clean hospital rooms, which could hold the key to preventing the spread of "superbugs" - in turn, saving countless dollars and, most importantly, lives.

Researchers observe major hand hygiene problems in operating rooms
An observational study by Sahlgrenska Academy researchers at a large Swedish hospital found 2,393 opportunities for hand disinfection and/or aseptic techniques. Doctors and nurses missed 90% of the opportunities.

Case study: Nebraska's Ebola isolation and decontamination approach
The Nebraska Biocontainment Unit (NBU), located at the Nebraska Medical Center, has shared its protocol for Ebola patient discharge, handling a patient's body after death and environmental disinfection in the March issue of the American Journal of Infection Control, the official publication of the Association for Professionals in Infection Control and Epidemiology (APIC).

Hygiene practices affect contact lens case contamination, reports Optometry and Vision Science
Contact lens wearers who don't follow certain hygiene habits have increased bacterial contamination of their contact lens cases, reports a study in the February issue of Optometry and Vision Science, official journal of the American Academy of Optometry.

Gold nanoparticles show promise for early detection of heart attacks
NYU Polytechnic School of Engineering professors have been collaborating with researchers from Peking University on a new test strip that is demonstrating great potential for the early detection of certain heart attacks.

New contaminants found in oil and gas wastewater
Duke University scientists have discovered high levels of two potentially hazardous contaminants, ammonium and iodide, in wastewater being discharged or spilled into streams and rivers from oil and gas operations in Pennsylvania and West Virginia.
More Disinfection Current Events and Disinfection News Articles

Russell, Hugo and Ayliffe's Principles and Practice of Disinfection, Preservation and Sterilization

Russell, Hugo and Ayliffe's Principles and Practice of Disinfection, Preservation and Sterilization
by Adam P. Fraise (Author), Jean-Yves Maillard (Author), Syed Sattar (Author)


The new edition of this established and highly respected text is THE definitive reference in its field. It details methods for the elimination or prevention/control of microbial growth, and features: * New chapters on bioterrorism and community healthcare * New chapters on microbicide regulations in the EU, USA and Canada * Latest material on microbial resistance to microbicides * Updated material on new and emerging technologies, focusing on special problems in hospitals, dentistry and pharmaceutical practice * Practical advice on problems of disinfection and antiseptics in healthcare * A systematic review of sterilization methods, with uses and advantages outlined for each * Evaluation of disinfectants and their mechanisms of action with respect to current regulations The differences...

Disinfection of Root Canal Systems: The Treatment of Apical Periodontitis

Disinfection of Root Canal Systems: The Treatment of Apical Periodontitis
by Nestor Cohenca (Editor)


Clean root canal systems are essential for successful endodontic treatment. With contributions from leading endodontists from around the world, Dr. Nestor Cohenca here presents the etiology of endodontic disease caused by the endodontic biofilm and all therapies available to predictably disinfect the root canal system, thus increasing successful endodontic outcomes. Disinfection of Root Canal Systems: The Treatment of Apical Periodontitis is an evidence-based manual that describes root canal anatomy, the endodontic biofilm, and the role of disinfection before presenting the most up-to-date methods of irrigation and disinfection. Individual chapters are devoted to each method, such as positive pressure irrigation, apical negative pressure irrigation, sonic activation, photodynamic therapy,...

Disinfection, Sterilization, and Preservation

Disinfection, Sterilization, and Preservation
by Seymour S Block (Editor)


Now in its thoroughly revised, updated Fifth Edition, this volume is a comprehensive, practical reference on contemporary methods of disinfection, sterilization, and preservation and their medical, surgical, and public health applications. More than a third of this edition's chapters cover subjects never addressed in previous editions.New topics covered include recently identified pathogens, microbial biofilms, use of antibiotics as antiseptics, synergism between chemical microbicides, pulsed-light sterilization of pharmaceuticals, and new methods for medical waste management. Close attention is given to infection control problems posed by endoscopes, implants, prostheses, and organ transplantation and to prevention of opportunistic infections in immunocompromised patients.A Brandon-Hill...

Disinfection, Sterlization, and Preservation

Disinfection, Sterlization, and Preservation
by Seymour S. Block (Author)


Examines the chemical and physical agents used for sterilization, and substances used as antiseptics and disinfectants. Topics new to this edition include the measuring of controlling hepatitis, compounds inactivating AIDS, germfree environments, and antimicrobial agents in agriculture.

Disinfection Efficiency and Dose Measurement of Polychromatic UV Light (Awwarf Report S)

Disinfection Efficiency and Dose Measurement of Polychromatic UV Light (Awwarf Report S)
by K Linden (Author)


There is currently intense interest in the use of ultraviolet technology for helping to meet future regulations relating to improved microbial inactivation and decreased disinfection byproducts (DBPs). Much of this interest has been fueled by recent research indicating the effectiveness of UV technologies for the inactivation of Cryptosporidium . This scientific discovery, combined with proposed regulations concerning DBPs in the United States, has resulted in a need to evaluate the feasibility and effectiveness of UV irradiation for use as a disinfectant for drinking water. The objectives of this project were to: (1) develop and evaluate physical, chemical, and biological methods for calculating effective germicidal UV dose from medium-pressure (MP) and Pulsed-UV (P-UV) lamps; ...

Disinfection By-Products in Drinking Water: Occurence, Formation, Health Effects and Control (ACS Symposium Series)

Disinfection By-Products in Drinking Water: Occurence, Formation, Health Effects and Control (ACS Symposium Series)
by Tanju Karanfil (Editor), Stuart W Krasner (Editor), Paul Westerhoff (Editor), Yuefeng Xie (Editor)


Since their discovery, disinfection by-products (DBPs) have become one of the major driving forces in drinking water regulations, research and water utility operations throughout the world. The list of DBPs that can occur in treated drinking waters has grown from a few trihalomethanes to a long list of halogenated and non-halogenated organic or inorganic compounds. This list is expected to continue to grow as the analytical techniques are improved, as more information on their toxicity is developed, and as more occurrence studies are conducted. This book documents the latest DBP research findings, including emerging issues and state-of-the-art studies. Specifically, papers on the occurrence, formation, control, and health effects of emerging (unregulated) halogenated (e.g., brominated)...

Disinfection and Decontamination: Principles, Applications and Related Issues

Disinfection and Decontamination: Principles, Applications and Related Issues
by Gurusamy Manivannan (Editor)


In the battle between humans and microbes, knowledge may be not only the best weapon but also the best defense. Pulling contributions from 34 experts into a unified presentation, Disinfection and Decontamination: Principles, Applications, and Related Issues provides coverage that is both sophisticated and practical. The book reviews the fundamentals, explores the interdisciplinary nature of the science, and includes discussions of regulatory and legal issues. While the chapters present in depth coverage of infections in hospitals, they also widen their scope to include laboratories outside the healthcare environment. Based on practical experience, the volume examines recent advances in the research, development, and applications for disinfection and decontamination in many different...

Disinfection Byproducts in Drinking Water: Formation, Analysis, and Control

Disinfection Byproducts in Drinking Water: Formation, Analysis, and Control
by Yuefeng Xie (Author)


The EPA has established regulations which classify four types of disinfection byproducts - TTHMs, haloacetic acids, bromate, and chlorite - and requires public water systems limit these byproducts to specific levels. Most of the information required to comply with these standards is either scattered throughout the literature or derived from conferences or symposiums. Disinfection Byproducts in Drinking Water: Formation, Analysis, and Control pulls all the information together to provide a needed organized presentation of disinfection byproduct analysis, formation, and control.

The author begins with an introduction to all disinfection byproducts (DBPs), including their nomenclatures, molecular structures, and formation. He discusses the effects of various water quality parameters...

Disinfection of Pipelines and Water Storage Facilities (Science and Technology)

Disinfection of Pipelines and Water Storage Facilities (Science and Technology)
by William Lauer (Author), Fred Sanchez (Author)


This field guide provides a handy, practical how-to book for drinking water personnel involved in disinfection processes. The book gives water operators common problems and provides solutions on disinfection procedures. Coverage includes chapters on chlorination chemicals, disinfection of new pipelines, pipe line repairs and storage facilities and highly chlorinated water; plus underwater inspections of storage facilities and their disinfection issues; a chapter on pipeline chlorination simplified and indexes on calculations of tank volumes and pipleline continuous feed method.

Disinfection, Sterilization and Preservation

Disinfection, Sterilization and Preservation
by Seymour S. Block (Author)




© 2015 BrightSurf.com