Increasing awareness of the health implications of environmental change in developing areas demands ongoing evaluation of the composition and context of unique human and environmental systems. The relationship between the ecology of emergent and resurgent infectious disease and land degradation is an uncertain aspect of environmental influences on human health that varies in different development contexts. An approach for examining a dynamic health and environment nexus is suggested based on combining ideas about health ecology with notions of sustainable development. The rationale is derived from the experience of research on changing diarrhoeal disease endemicity and epidemicity in central Mozambique, recent moves towards poverty reduction through food and livelihood security in Zambézia province, and the development of a geographic health information system to control malaria. Themes include analysing the influence of land degradation on incidence of infectious diseases, situating human health in land-based notions of sustainable development, and communality between environmental health care and land-based poverty reduction policies. The paper emphasizes that environmental health surveillance and care must be responsive to changing health ecologies in varying development landscapes and that common policy directives should be sought in avoiding both human ill-health and land degradation.