Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Harvested rainwater harbors pathogens

27.02.2014

South Africa has been financing domestic rainwater harvesting tanks in informal low-income settlements and rural areas in five of that nation's nine provinces. But pathogens inhabit such harvested rainwater, potentially posing a public health hazard, especially for children and immunocompromised individuals, according to a team from the University of Stellenbosch. The research was published ahead of print in Applied and Environmental Microbiology.

International studies had indicated that harvested rainwater frequently harbors pathogens, and that, in light of the financing of harvesting tanks, drove the investigators to study the matter locally, says principal investigator Wesaal Khan.

The sampling was conducted in the Kleinmond Housing Scheme, which was initiated by the South African Council for Scientific and Industrial Research and the Department of Science and Technology. The houses, designed to be sustainable, are approximately 400 square feet, with alternative technologies such as solar panels and the rainwater tanks.

The list of predatory prokaryotes the investigators found includes Legionella (found in 73% of samples), Klebsiella (47%) Pseudomonas (19% of samples), Yersinia (28%), Shigella (27%), and others. They also found some protozoan parasites, including Giardia (25% of samples).

Many of the pathogens are normal fresh water inhabitants, but Salmonella (6% of samples) indicates human fecal contamination, while Yersinia are markers of fecal contamination by wild and domestic animals, according to the report.

Residents, many of whom are little-educated and unemployed, typically use the rainwater for washing clothes and house-cleaning, but about one quarter of people polled in the study said they used it for drinking, as well. The finding that coliforms and Escherichia coli counts from rainwater samples—markers of fecal contamination—always significantly exceeded drinking water guidelines, reinforces the World Health Organization's opinion that rainwater must be pretreated prior to use for drinking, says Khan.

Rainwater harvesting is needed in South Africa's "informal communities" because residents often depend on communal "standpipe" systems that frequently serve more than 100 people, who may have to walk as far as a third of a mile to get water, says Khan. Approximately 23,000 rainwater tanks have been installed, two thirds of them in the Eastern Cape and one third in KwaZulu Natal. Nearly 20% of South Africans lack sustainable access to water.

A copy of the manuscript can be found online at http://bit.ly/asmtip0214f. The final version of the article is scheduled for the April 2014 issue of Applied and Environmental Microbiology.

Applied and Environmental Microbiology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Jim Sliwa | EurekAlert!
Further information:
http://www.asmusa.org

More articles from Health and Medicine:

nachricht New tuberculosis blood test in children is reliable and highly specific
01.09.2014 | Swiss Tropical and Public Health Institute

nachricht Sugar substance 'kills' good HDL cholesterol, new research finds
01.09.2014 | University of Warwick

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

IT security in the digital society

27.08.2014 | Event News

Understanding the brain—neuroscientists meet in Göttingen

27.08.2014 | Event News

MEDICA EDUCATION CONFERENCE: Bessere Behandlung dank Biomarker

21.08.2014 | Event News

 
Latest News

Endangered Siamese Crocs Released in Wild

01.09.2014 | Ecology, The Environment and Conservation

Doing More with Less: New Technique Uses Fraction of Measurements to Efficiently Find Quantum Wave Functions

01.09.2014 | Physics and Astronomy

Simpler Process to Grow Germanium Nanowires Could Improve Lithium-Ion Batteries

01.09.2014 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>