The urban environment

Urban environment illustration
UNEP/Permdahl Vesm; UNEP/Shihua Zhao; UNEP/Carmel Fatima

Urban environments - web directory

A global directory of urban environment sites, including links to sites by UNEP, WHO (Healthy Cities Network), and other UN agencies (UN-HABITAT), as well as development/research/academic and civil society.

Directory of resources on transport, health and environment in developing countries

A global directory of resources and links on transport, health and environment issues in developing countries, along with selected developed country links, including the PEP, the new UNECE/WHO Pan-European Programme clearing house for Transport, Health and Environment.

Policy Brief – Health and environment linkages in the urban environment

Over the next thirty years, most of the world’s population growth will occur in cities and towns of poor countries (1). Even while population growth rates in Asia, for instance, are falling dramatically, the region will see an absolute increase of nearly a billion people over the next three decades –growth concentrated mostly in urban areas (2). In Africa, the urbanization process also is occurring apace. For example, in the United Republic of Tanzania, the population of Dar es Salaam is doubling every 12 years (3).

Rapid, unplanned and unsustainable patterns of urban development are making developing cities focal points for many emerging environment and health hazards. As urban populations grow, the quality of the urban environment, will play an increasingly important role in public health with respect to issues ranging from solid waste disposal, provision of safe water and sanitation, and injury prevention, to the interface between urban poverty, environment and health.

deaths from urban air pollution map

Unsustainable patterns of transport and urban land use are a driver, or root cause, of a number of significant, and interrelated environment and health hazards faced by urban dwellers in developing countries (4). These health and environment linkages cut across a range of policy sectors and thus are often overlooked in policymaking. They are a focus of this Priority Risks section on the urban environment.

Environment and health linkages

  • Urban air pollution – of which a significant proportion is generated by vehicles, as well as industry and energy production – is estimated to kill some 1.2 million people annually (5). Today, many developing world cities face very severe levels of urban air pollution – higher than developed world counterparts (6, 7).
  • Road traffic accidents contribute a further 1.3 million deaths annually; low- and middle-income countries bear 90 % of the death and injury toll. Degradation of the built urban and rural environment – particularly for pedestrians and cyclists – has been cited as a key risk factor (4, 5, 8, 9).
  • Current patterns of urbanization and motorization also are associated with more sedentary lifestyles, diminished space and opportunities for physical activity, and a consequent surge in related non-communicable diseases (10, 11, 12). Physical inactivity is estimated to be responsible for some 3.2 million deaths globally every year, as a result of disease such as heart ailments, cancer and diabetes (5, 12).

Cost-effective strategies to address such linkages do exist. More integrated transport and land use – including the development of high capacity, dedicated busways and pedestrian/cycle networks – have become central to policy in Latin American cities such as Bogotá and Curitiba, and similar models are being examined/tested in other cities of Africa, the Americas and Asia. Reducing transport pollution emissions, and their health impacts, through the use of cleaner fuels and vehicle technologies has been an issue addressed in the African context, and elsewhere. These experiences will be described in more detail in a forthcoming policy brief and directory of resources.

  • World urbanization prospects: The 2003 revision. United Nations Department of Economic and Social Affairs, Population Division: New York. (Accessed August, 2004:
  • Health effects of outdoor air pollution in developing countries of Asia; a literature review. Health Effects Institute, April 2004. (Accessed July, 2004 : http: de Jong, R. The environmental impact of cities. In Habitat Debate. United Nations Human Settlements Programme - UN-Habitat . June 2002, 8(2)5.
  • Montgomery, M., et al., eds. N.R.C. Panel on Urban Population Dynamics.Cities Transformed: Demographic Change and its Implications in the Developing World.. London, Earthscan, 2004:529.
  • The world health report 2002 – reducing risks, promoting healthy life. Geneva, World Health Organization, 2002.
  • Kenworthy J, Laube F. Urban transport patterns in a global sample of cities and their linkages to transport infrastructures, land use, economics and environment. World Transport Policy and Practice, 2002, 8(3):5–20.
  • Health effects of outdoor air pollution in developing countries of Asia: a literature review. Boston, Health Effects Institute, 2004.
  • Peden M et al., eds. World report on road traffic injury prevention. Geneva, World Health Organization, 2004.
  • Nantulya VM, Reich MR. The neglected epidemic: road traffic injuries in developing countries. British Medical Journal, 2002, 324(7346):1139–1141.
  • Neglected global epidemics: three growing threats. The world health report 2003 – shaping the future. Geneva, World Health Organization, 2003.
  • Physical activity, environmental issues. Geneva, World Health Organization (accessed 4 October, 2004).
  • Dora C, Phillips M, eds. Transport, environment and health. Copenhagen, World Health Organization Regional Office for Europe, 2000 (WHO Regional Publications, European Series, No. 89).
  • The world health report 2002 - reducing risks, promoting healthy life. Geneva, World Health Organization, 2002.