Friday, January 8, 2010

Are clay pots safe for household use?

contributed by Sonali Palchaudhuri

Understanding the intricacies of the drinking water supply chain in rural Uganda has been an ongoing effort for Uganda Village Project. No matter how pristine the water may be when it comes from the source (and most rural sources are more like muddy puddles than pristine fountains), there are numerous opportunities for the water to be contaminated with bacteria that can kill the most vulnerable community members in villages - the children, the sick, and the elderly. Early on, we realized that frequently, safe water is contaminated through the common practice of dipping into the clay storage pots. For years now, we have been using innovative technologies to try to make the safe water chain 'humanproof' - to make it so that safe water automaticallystays safe, without requiring much behavior change or financial investment on the part of community members.

UVP has been working with local potters to produce new clay pots modified with spigots to access water safely. The pots have a small neck designed to keep even children's hands from reaching inside. These new clay pots have been going through testing to make sure we have a high quality product to provide for the local villagers, as well as to set up a strong social business with local entrepreneurs and potters. Of course, the first priority for these pots is to make sure that they improve the health of users. Thus, we wanted to make sure the clay being used did not contain any harmful contaminants that could leach into the drinking water. Samples of clay were collected from a variety of potters and tested in University of Michigan laboratories with an Environmental Scanning Electron Microscope (ESEM), to see what materials the clays were composed of. Fortunately, preliminary observations of the 11 samples suggest that they are all free of dangerous compounds, like mercury and lead. They are mostly composed of the normal materials found in clay – aluminum, oxygen, silicon, carbon – with trace amounts of titanium, iron and copper that we will continue to evaluate. We continue to look at these clay samples and determine if we should exclude any particular clay source, or be aware of any properties that would make the clay more susceptible to bacterial contamination.

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