Water and infectious diseases: Emerging issues

Most public and private water supplies in developed countries are readily available and safe for human consumption. This is not true in developing countries. There is a huge economic and social cost from frequent illness caused by contaminated water (some 17% of under-five deaths in developing countries result from infectious diarrhea) and time spent finding potable water. Some water contamination can be avoided, some can be removed and some makes the water unusable. Microbial contamination of drinking water has been recognized as a threat to health for millennia, but the problem persists, barely abated. This paper will discuss the principle sources of microbial contamination, ways this contamination can be avoided, the choices for making contaminated water potable and the policy implications of the cost and efficacy of the various choices.