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Distribution of the systems began in 1997, and in the summer of 1999 we began revisiting filters in order to determine how well they were working through their constant usage. Water from the filters is tested both chemically and microbiologically, and water taken directly from the sources used by the villagers is tested as well in order to assess the demand on the filters. During the summer of 2000, the project was expanded to include an epidemiological study to assess the impact of the filter intervention on the health of the communities. This project was started by Rachel Woodruff, a student from the Emory School of Public Health, working under the direction of Dr. Robert Quick of the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia. The chemical and microbiological analysis of water as well as the epidemiological impact assessment provide good opportunities for student participation. |
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| Chemical Analysis
Filters and their water sources are currently being tested for the following parameters: temperature, pH, turbidity (NTU), hardness, and total and free chlorine. |
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Microbiological Analysis
With our microbiological analysis we assess the number of Escherichia coli (a fecal coliform bacteria) present in 100 mL of both filtered and crude water. 100 mL samples are filtered through a sterile membrane, which is then incubated in m-Coliblue24 (Hach Chemical Co.) from 24 to 48 hours. M-Coliblue24 is a differential medium resulting in blue fecal coliform (E. coli) colonies and red total coliform colonies. |
Preparing water samples for membrane filtration and incubation. |
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Cultures obtained from the water of two household storage containers. |
A culture from a canal used as a source of water. |
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Epidemiological Study
Providing a community with a source of potable water doesn't necessarily lead to a decrease in the incidence of water-related diseases. For that reason, assessing the impact of a potable water source requires an epidemiological study in which the rate of disease is measured before and after the intervention. Rachel Woodruff, from the Rollins School of Public Health at Emory University, is currently engaged in just such a study in order to determine if the presence of the filters in a community does, in fact, lead to a decrease in the incidence of water-borne disease.