The city we now call home recently ranked 12th out of 25 on a quite impressive list.
This list was developed based on the Mercer Human Resource Consulting's 2007 Health and Sanitation Rankings as part of their 2007 Quality of Life Report. This Report ranked 215 cities worldwide according to the following parameters: levels of air pollution, waste management, water potability, hospital services, medical supplies, and the presence of infectious disease.
All joking aside, the realities for residents of most of these cities can be very harsh, in places where "black plumes of smoke, acid rain and free-flowing sewage are part of everyday life." Also, such conditions are almost guaranteed to bear negative affects on the population's health and by extension life expectancy. Not so surprisingly, life expectancy here is extremely low. The UN reports that life expectancy for men is 55 years, for women 56 years, while USAID estimates life expectancy to be a bit lower at 48 years (due in part of the ravaging effects of HIV/AIDS and malaria). In either case, these statistics paint a dire picture, and anecdotally, I can attest to the fact that it is a rare sight to see elderly people around here. I can only imagine the horrendous conditions and associated consequences for the health of the residents of the cities unfortunate enough to rank ahead of Dar es Salaam on this list.