Throughout the history of public health, effectively communicating about health risks with a broad range of constituents has proven a fundamental and enduring challenge. John Snow, for example, faced local officials who were ‘‘reluctant to believe’’ his claim that the epicenter of the 1854 cholera outbreak in London was the Broad Street water pump, and he secured their permission to remove the pump handle only on an experimental basis. Similarly, communication efforts to contain the spread of HIV in the United States met strident resistance from health care, public health, and community constituents. More recently, unprecedented crises and emergency events occurring around the world (e.g., the 2004 Indian Ocean/Asian tsunami) have highlighted public health risk communication shortcomings that mitigated mobilization and coordination of public health resources, ‘‘undermined public trust and compliance, and unnecessarily prolonged economic, social, and political turmoil’’ (WHO, 2005: 1). Indeed, as Edward Baker, Assistant U.S. Surgeon General, observed:
the major public health challenges since 9/11 were not just clinical, epidemiological, technical issues. The major challenges were communication. In fact, as we move into the 21st century, communication may well become the central science of public health practice. (qtd. in Galvez et al., 2007)Contemporary public health risk communication principles and practices have emerged over the last 50 years in response to such challenges; first from natural, industrial, and environmental disaster management, then as an integral component of health promotion endeavors targeting infectious and chronic disease prevention and management, and most recently in response to the threat of terrorism. Although there are distinct literatures detailing the unique application of risk communication to each of these public health contexts, several commonalities and generalizations are evident.