ABSTRACT
We are all naturally concerned about our own health and the health of others around us. The main focus of our concerns will, however, be different depending on whether we live in a developed nation or in a less developed part of the world. In the relatively recent past, communicable gastrointestinal diseases were major causes of infant mortality worldwide and were often transmitted through drinking water. This disease source has been combated with success by the construction of sewage systems and the provision of clean, disinfected drinking water supplies. Epidemics of the more lethal gastrointestinal diseases such as cholera still occur in rural populations with no clean drinking water and in towns where drinking water disinfection has failed.
