Sub-standard housing, unsafe water and poor sanitation in densely populated cities are responsible for 10 million deaths worldwide every year, and are a major factor in preventable environmental hazards, which are responsible for 25 percent of all premature deaths worldwide. Waterborne diseases alone kill 4 million infants and children annually. Diseases caused by poor housing conditions and a lack of safe and sanitation also cost much more than prevention. By not dealing with these conditions, governments are eventually burdened with extremely high health expenditures for their populations. The plague outbreak of 1994 in Surat, India a comparatively prosperous city was attributed mainly to unsanitary housing conditions.
Homelessness is a problem in developed as well as in developing countries.
In London, for example, life expectancy among the homeless is more than 25 years lower than the national average. Homelessness and poor housing conditions are at the root of all of these problems. Urban areas have the resources to solve the housing problems cities account for 50 to 80 percent of most developing countries Gross National Product but waste and mismanagement of urban resources cripples the effort. Despite their problems, cities will remain the engines of social, economic and environmental development in the next century and provide the greatest opportunity for the poor. According to the report, the urban poor are three to 10 times better off economically than the rural poor.