Low-tech solution has high rate of success in fighting water diseases
Jan 12, 2008
By Prashant Nair
Special to The Chapel Hill News (North Carolina, USA)
CHAPEL HILL -- If the Carolina Global Water Partnership succeeds in bringing safe water to rural Cambodia, it will likely be due to household water filters that cost just a few dollars each.
Mark Sobsey, the environmental scientist at UNC's School of Public Health who heads the project, successfully tested two kinds of water purification systems: ceramic filters and biosand filters.
Ceramic water purifiers look like flower pots and contain clay and a combustible organic material like sawdust. When fired in the kiln, the sawdust disappears, leaving behind tiny holes that trap bacteria and parasites. The filter can be attached to a faucet and has a plastic receptacle to hold water.
"You fill it at night and safe drinking water is available in the morning," Sobsey said.
Non-governmental organizations Research Development International, International Development Enterprises and the Cambodian Red Cross have joined hands to manufacture and sell the filters at $8 a piece. They sell about 500 filters a week in three factories.
Sobsey has evidence the filters work. "We saw a 45 percent reduction in diarrheal disease in families that used the filters versus those that did not," he said. Diarrhea causes more than 80 percent of deaths among Cambodian children under 5 years old.
Biosand filters consist of a bed of sand particles atop a layer of gravel that prevents the sand from washing away. An outlet at the bottom cycles water through the sand layer before it is discharged. Covered with water at all times, the sand contains harmless microbes that kill pathogens in the water by competing for nutrients with the pathogens or directly ingesting the pathogens.
"These are not high-tech treatment technologies," said Peggy Bentley, a public health expert at the UNC School of Public Health. "We know that they work, but we just don't have the business models to sell them in the countries where they're needed."
Most of the filters now are subsidized, marketed and sold by the non-governmental organizations. The UNC group is collaborating with the Kenan Flagler Business School to create business models to make the filters commercially viable.
Lisa Jones Christensen, a business professor, will use her expertise on microfinancing to promote the filters. Microfinancing involves giving small loans to local women to help them buy filters in bulk and sell them to households.
"It works on a social model where women get together with creditors and agree to pay back loans at a stipulated time. Some women may cover for others who are unable to repay loans on time," Christensen said. "There's a social cushion that the standard bank does not provide. That's the secret to the success of microfinance."
Water-use habits and economic conditions vary widely across Cambodia, which may make finding a one sales strategy fits all solution unlikely.
"We're entering the markets of developing countries all the way from the homes of the poor to indigenous corporations, and that has its own challenges," Christensen said. "The poor will be suspicious that we have corporate interests, and the corporations will wonder when the philanthropy will end and the money-making begin."
Prashant Nair is a graduate student in medical journalism at UNC and writes about medicine, health and environmental issues. He can be reached at nair@email.unc.edu
Jan 12, 2008
By Prashant Nair
Special to The Chapel Hill News (North Carolina, USA)
CHAPEL HILL -- If the Carolina Global Water Partnership succeeds in bringing safe water to rural Cambodia, it will likely be due to household water filters that cost just a few dollars each.
Mark Sobsey, the environmental scientist at UNC's School of Public Health who heads the project, successfully tested two kinds of water purification systems: ceramic filters and biosand filters.
Ceramic water purifiers look like flower pots and contain clay and a combustible organic material like sawdust. When fired in the kiln, the sawdust disappears, leaving behind tiny holes that trap bacteria and parasites. The filter can be attached to a faucet and has a plastic receptacle to hold water.
"You fill it at night and safe drinking water is available in the morning," Sobsey said.
Non-governmental organizations Research Development International, International Development Enterprises and the Cambodian Red Cross have joined hands to manufacture and sell the filters at $8 a piece. They sell about 500 filters a week in three factories.
Sobsey has evidence the filters work. "We saw a 45 percent reduction in diarrheal disease in families that used the filters versus those that did not," he said. Diarrhea causes more than 80 percent of deaths among Cambodian children under 5 years old.
Biosand filters consist of a bed of sand particles atop a layer of gravel that prevents the sand from washing away. An outlet at the bottom cycles water through the sand layer before it is discharged. Covered with water at all times, the sand contains harmless microbes that kill pathogens in the water by competing for nutrients with the pathogens or directly ingesting the pathogens.
"These are not high-tech treatment technologies," said Peggy Bentley, a public health expert at the UNC School of Public Health. "We know that they work, but we just don't have the business models to sell them in the countries where they're needed."
Most of the filters now are subsidized, marketed and sold by the non-governmental organizations. The UNC group is collaborating with the Kenan Flagler Business School to create business models to make the filters commercially viable.
Lisa Jones Christensen, a business professor, will use her expertise on microfinancing to promote the filters. Microfinancing involves giving small loans to local women to help them buy filters in bulk and sell them to households.
"It works on a social model where women get together with creditors and agree to pay back loans at a stipulated time. Some women may cover for others who are unable to repay loans on time," Christensen said. "There's a social cushion that the standard bank does not provide. That's the secret to the success of microfinance."
Water-use habits and economic conditions vary widely across Cambodia, which may make finding a one sales strategy fits all solution unlikely.
"We're entering the markets of developing countries all the way from the homes of the poor to indigenous corporations, and that has its own challenges," Christensen said. "The poor will be suspicious that we have corporate interests, and the corporations will wonder when the philanthropy will end and the money-making begin."
Prashant Nair is a graduate student in medical journalism at UNC and writes about medicine, health and environmental issues. He can be reached at nair@email.unc.edu
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