This area of concern is particularly important since it relates directly to the environmental conditions within which large urban populations have to live. The rapid, especially the unplanned and unsustainable patterns of urban development characteristic of urbanization in Caribbean cities require concurrent focus on issues of public health in the urban environment, both from the standpoint of policy and regulations. The World Health Organization for example, has notably recognized that as urban populations grow, the quality of global and local ecosystems, and the urban environment, will play an increasingly important role in public health with respect to several risk related issues, ranging from solid waste disposal, provision of safe water and sanitation, and injury prevention, to the interface between urban poverty, environment and health. The issue of urban informality as a particular feature of Caribbean urbanization is notably a high priority issue on the Caribbean Urban Agenda. Key considerations in the debate on this issue revolve around tenure security, informal settlements in urban and peri-urban areas and the informal urban economy.