Ever since risk assessment has been used in the federal government to support decision-making, there has been a recognition that government agencies had no choice but to communicate with stakeholders, including the public. In 1987, William Ruckelshaus, former EPA Administrator, noted that the question is not whether to involve the public in decisions about risk, but how. In 1989, the National Research Council produced a report on risk communication and offered the following definition:
The risk communication process must address the following questions: Who will make the decision? How will technical estimates of risk and other factors be evaluated? How, when, and where will stakeholders' concerns be managed? What information do the stakeholders want or need?
Several characteristics of risk comparison and communication should be considered when evaluating the effectiveness of approaches for the study and practice of risk communication. Risk comparison can be a simple one-dimensional comparison or a more complex multidimensional comparison. At the simple end, similar risks and only a few aspects of each are compared. At the complex end, multiple risks are compared across a variety of dimensions. The simpler the comparison, the easier it is to communicate and produce a more predictable response. However, a simple comparison might not represent the situation accurately. If the risk comparison is more complex, it can yield richer perspective for the decision-maker and public, but might also be an attempt to relate risks that are so dissimilar that, to some target audiences, comparison does not seem relevant.
Several approaches, both theoretical and empirical, have been used to understand how target audiences respond to risk messages and to improve the quality of communication. Psychometric models have examined the effect of qualitative risk characteristics, such as whether a risk is new or familiar, in explaining how groups respond to risk messages. Other models are more econometric; they are based on contingent evaluation of perceived threats and perceived benefits. The latter seem more explanatory, but the amount of comparative research is very limited.
The mental-models approach seeks to understand how people use information to make decisions by using a structured-interview technique to identify knowledge, beliefs, missing information, and misconceptions. Providing information in a manner that conforms to the audience's "mental model" improves comprehension. Providing missing information and correcting misconceptions make decisions more consistent between lay and expert groups.
Because our theoretical understanding of risk communication is not full, a practical empirical approach is most effective. Focus-group and survey research suggests that a variety of qualitative characteristics of risk can influence the response to risk comparisons and that risk comparisons can exacerbate or trivialize concerns. Therefore, formative research, including message testing, should be a part of any risk-communication activity.
The research on risk communication provides insights into the utility of risk comparisons. They can be useful but only when they are a part of an overall communication strategy. This strategy requires that the communicator: understand the nature of the risk--both the hazard that it presents and the qualitative attributes that influence perception by the target audience; understand the audiences that are being addressed and their relationship to the hazard; understand how the risk comparison interacts with other components of the message; and have a way to evaluate the audiences' response.
Experience from risk communication suggests that risk comparisons should be made in ways that provide cues to action and that respect the values of the participants in the process. Failure to consider social and political issues and values will diminish the quality of the discussion. That does not mean that the scientific components should be de-emphasized in deference to values, but the technical components and their implications for risk management must be effectively and persuasively conveyed to all stakeholders, including the public.
Most research has been descriptive rather than experimental. It has been focused on specific risks, such as radon and toxic substances, rather than taking a more comprehensive view of environmental risks. The kind of community-based research in the 1960s and 1970s that has underpinned the prevention movement in health care has not been done for the environment. Some of our pressing environmental problems are more amenable to a broad public-health approach than to the traditional command-and-control regulatory approach.
The complex nature of risk communication calls into question the value of requiring simple comparisons of risk end points with either common risks of daily life or other chemical or physical risks. Without a context, this information might yield wrong or confusing messages for the public. For most listeners, it evades the primary questions, "Will it hurt me?" Therefore, risk-communication efforts should provide both comparisons and context, which can depend on factors beyond risk numbers.
Recommendations for Practice
Include communication as a specific component of all risk-management plans and budgets (10% of available resources is a good rule of thumb).
Hold risk-program managers accountable for meeting communication objectives.
Use appropriate formative research to underpin communication efforts.
Communicate uncertainty with care. Because stakeholders, including the public, might react to uncertainty in unpredictable ways, ensure that a good mechanism to evaluate what has been communicated is in place.
Use effective communication strategies to build and extend the consensus among stakeholders, including the public. Clear consensus-building (e.g., with comparative risk assessments) can provide support for using more persuasive communication techniques.
Recommendations for Research
Conduct experimental studies on the influence of risk comparisons on attitudes and behavior of stakeholders, including the public.
Fund innovative demonstration efforts at the national, state, and local levels.
Conduct research on the effectiveness of various techniques for presenting uncertainties in environmental risk assessment.
Conduct research on strategies that make regulatory standards
flexible.