Sunlight plus lime juice makes drinking water saferApril 18, 2012
"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
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.
Pharmaceuticals, personal care products could taint swimming pools
A new study suggests pharmaceuticals and chemicals from personal care products end up in swimming pools, possibly interacting with chlorine to produce disinfection byproducts with unknown properties and health effects.
How Long Can Ebola Live?
The Ebola virus travels from person to person through direct contact with infected body fluids.
US radiology departments prepare for Ebola
Radiologists from the National Institutes of Health (NIH) and Emory University School of Medicine have issued a special report on radiology preparedness for handling cases of Ebola virus.
Can HIV be transmitted via manicure instruments?
The Centers for Disease Control and Prevention (CDC) lists numerous potential alternative sources of HIV transmission in addition to the known classical modes for acquiring the AIDS virus.
UPMC investigation into GI scope-related infections changes national guidelines
National guidelines for the cleaning of certain gastrointestinal (GI) scopes are likely to be updated due to findings from UPMC's infection prevention team.
E. coli outbreak at hospital associated with contaminated specialized GI endoscopes
Despite no lapses in the disinfection process recommended by the manufacturer being identified, specialized gastrointestinal endoscopes called duodenoscopes had bacterial contamination associated with an outbreak of a highly resistant strain of E coli at a hospital in Illinois.
'Deadly diarrhea' rates nearly doubled in 10 years: Study
Infections with the intestinal superbug C. difficile nearly doubled from 2001 to 2010 in U.S. hospitals without noticeable improvement in patient mortality rates or hospital lengths of stay.
More Disinfection Current Events and Disinfection News Articles