Conservation medicine focuses on the cross-over between ecosystem, animal and human health. Conservation biology emerged as a "crisis" discipline in the 1980s at the interface between ecology, environmental policy and management; and work in the biomedical and veterinary sciences is now being folded into conservation biology, to explore the connections between animal and human health. It traces the environmental sources of pathogens and pollutants in order to develop a rounded, interdisciplinary understanding of the ecological causes of changes in human and animal health, and the consequences of diseases to populations and ecological communities.