Risk can be defined broadly as a condition in which there is a possibility that persons or property could experience adverse consequences. Some people, by virtue of their access to data or their specialized expertise in interpreting those data, have more information than others about the risk of a particular hazard and about ways in which that risk can be managed. These risk analysts have a responsibility to convey their assessments to decisionmakers who must determine what action to take in response to the risk that the analyst has characterized. These assessments typically define risk in terms of the likelihood that an event of a given magnitude will occur at a given location within a given time period and describe the expected consequences that the event will inflict on persons, property, and social functioning. The decisionmakers to whom the analysts communicate this information can be either the population at risk or emergency managers who are responsible for protecting the population at risk. In either case, the principal reason for risk communication is to initiate and direct protective action.
Risk communication has become a common concept in recent decades—appearing in many contexts (infectious diseases, food additives, natural hazards, routine effluents, and technological accidents) and referring to many target groups (employees, households, minority groups, and legislators, to name only a few). The principal concern of this chapter will be events that, because of their rapid onset and the large amounts of energy or materials released, have the potential to cause significant numbers of casualties and substantial amounts of property damage unless timely and effective action is taken.
Some of these extreme events originate in the natural environment and, thus, are known as natural hazards. Events involving the release of substantial amounts of energy (e.g., earthquakes) can cause immediate destruction of buildings and infrastructure, inflicting many casualties (deaths, injuries, and illnesses) and much disruption to social, economic, and political activities. In some cases, these effects are immediate, whereas in other cases they might take years to manifest themselves.
In addition to hazards originating in the natural environment, there are also hazards that are transmitted through the natural environment. These include some, but not all, of what are commonly referred to as technological hazards. Some technological hazards can have a very rapid onset and have the potential for killing many people very quickly unless there is a prompt and effective emergency response. Others involve the cumulative effect of routine air- or water-borne releases from technological facilities or contamination of food and drugs. Many exposures to these hazards unfold over an extended period of time and the adverse health effects even more delayed—frequently producing low incidence rates of disease in the affected population. Regardless of the speed of onset or the persistence of the hazard, the same principles of risk communication are likely to apply.
There is, however, a temporal distinction that is central to the organization of this chapter—the amount of time between the detection of the hazard and the onset of exposure. A risk communication effort addressing the imminent threat of an extreme event is referred to as a warning; it is intended to produce an appropriate emergency response. By contrast, a risk communication program addressing the long-term potential for such events to occur is often known as a hazard awareness program; such efforts are intended to produce long-term hazard adjustments. There are quite distinct research literatures on natural and technological hazards that have produced similar conclusions about warnings but have encountered an important difference in the case of hazard awareness programs. Natural hazards seem to arouse substantially less concern than technological hazards, so risk communication programs about the long-term threat of natural hazards generally have sought to increase public concern. By contrast, risk communication programs about the long-term threat of technological hazards have more frequently sought to decrease public concern. Research on technological risk perception has sought to explain why some hazards elicit more concern than others, and it appears the difference is due, at least in part, to such hazard characteristics as the voluntariness and controllability of hazard exposure and the degree of dread about its consequences (Slovic, 1987).
Risk communication attempts to promote appropriate protective behavior by those to whom the information is directed; such hazard adjustments to long-term threats include modifying the hazard, modifying the hazard’s impact by preventing specific effects, moving to another location, changing the land use to reduce hazard vulnerability, sharing the loss, or bearing the loss (Burton, et al., 1993). Alternatively, one can think of such behavior changes as disaster responses to an imminent threat by such actions as evacuating, sheltering in-place, expedient respiratory protection, or food interdiction (Drabek, 1986; Mileti, Drabek & Haas, 1975).
In general, this chapter will emphasize the communication of information to those who are actually at risk of exposure to a hazard, but also will recognize the need for communicating to those who think they are at risk of exposure to the hazard even if authorities do not share this belief. In the latter case, messages are sometimes needed to convince people they do not need to take protective actions because they will not be exposed to the hazard or because the actions being taken by authorities will be sufficient to protect them. Alternatively, such messages might be designed to convince people that hazard managers do not need to implement protective actions because the costs of responding outweigh the risk. Moreover, authorities are occasionally knowledgeable enough about citizens’ concerns that a one-way communication flow from them to citizens will produce results that are satisfactory to all concerned. In practice, however, authorities frequently need feedback from citizens and should expect such feedback whether or not they believe it is needed. For most environmental hazards, the risk communication process should be based upon a hazard analysis that identifies risk areas—the geographical locations in which the environmental extremes are expected to occur—and the mechanisms by which exposure can occur. The risk communication process also should be guided by a vulnerability analysis identifying the populations and property located in those risk areas. These analyses provide the basic data upon which messages can be formulated that describe the vulnerability of different population segments and the protective responses that are appropriate to reduce these risks.
It is important to recognize that one cannot focus exclusively on a risk analyst’s definition of the situation to generate risk messages. Unfortunately, many well-intended attempts at risk communication are based on the assumption that risk area populations fail to implement analysts’ protective action recommendations because they are unaware of or misperceive the risk. Thus, analysts assume that disseminating scientific information about the hazard agent will motivate people to adopt their protective action recommendations. This assumption is correct in some cases, but it substantially oversimplifies the risk communication process because it ignores the roles of the information source, the channel by which the information is transmitted, and the individual differences among message receivers. In addition, this naive approach to risk communication also ignores the effects of impediments to information processing such as competing demands for attention, the use of cognitive heuristics (simplified rules of thumb for processing complex information), and conflicts of the new information with people’s existing beliefs (Yates, 1990). Finally, such an approach neglects the social structural (community) and cultural environments in which communication processes are immersed (Gudykunst, 1998).
Instead, risk communication should be a process in which stakeholders share information about hazards affecting a community. The use of the term sharing is important because risk analysts and emergency managers must understand how different segments of the population at risk think about a hazard if they are to be effective in communicating with their audience. These population segments include businesses and households that are vulnerable to a specific hazard, as well as community and industry personnel who are responsible for managing a hazard in ways that reduce the risk to a level that is acceptable to the community.
People’s attentiveness to risk communication varies across the four emergency management functions—hazard mitigation, emergency preparedness, emergency response, and disaster recovery. Decades ago, Fritz (1968) observed most of the money and resources for emergency management are expended in connection with response and recovery activities. This is consistent with the cycle, noted in previous chapters, of significant citizen and government interest in disasters only during imminent threats and in the immediate aftermath of disasters. However, public attention declines significantly as time passes. Because considerable time is required to translate public concern into government budget allocations and coherent programs, many mitigation and preparedness programs have simply failed to be implemented (Birkland, 1997; Prater & Lindell, 2000).