Indicators of environmental health in the urban setting.

The North American population is approximately 80% urbanized and spends almost 90% of the time indoors. Accordingly, the built environment is the most important--one might almost say "natural"--human environment. Urban settlements incorporate within their boundaries natural ecosystems of plant and animal life (often highly adapted to the urban environment), and are in turn incorporated within wider bioregions and global ecosystems. But urban settlements are not just built and natural physical environments, they are social, economic, cultural and political environments; the whole constitutes an urban ecosystem. These ecosystems have profound implications for the physical, mental, social, emotional and spiritual well-being of their human inhabitants, as well as for human beings remote from these urban ecosystems. Therefore, this paper discusses urban ecosystems and human health and presents a framework for indicators of environmental health in the urban setting based on such an understanding. The concepts of environmental viability, ecological sustainability, urban livability, community conviviality, social equity, and economic adequacy are discussed in relation to human health and are used to organize proposed candidate indicators for urban ecosystems and public health.