This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
Agenda 21 suggests the survey of existing health, social and environmental conditions in cities including documentation of intra-urban differences.
The WHO Healthy Cities project has tried to be instrumental in tackling local environment and health (EH) needs by fostering a more integrated approach to health and urban development. By integrating health issues into urban development, it has been found that local politicians, community groups and individuals are brought together more readily. Local Agenda 21 activities have been a similar catalyst in some places. In general, the city EH planning approach begins by assessing the state of health in the city and identifies the key factors that promote or limit good health. Those health aspects and localities that are most in need of EH improvements can then be given priority. Projects are subsequently defined, funding secured and implementation scheduled. A further element of this approach is the networking of like-minded cities who share experiences of successful project outcomes. This has the benefit of reducing the need to re-invent an entirely new project design in each city.