Communicating environmental risk is central to the successful management of environmental hazards. The field of risk communication is rapidly evolving due to a better understanding of the importance of effective communication in the maintenance of a healthy environment, and due to social and technological changes that affect how
A gap exists between the priority assigned to different forms of environmental risk by the public and the priority assigned by technical experts. For example, experts believe that the health risk posed by hazardous waste sites is far less than that of indoor air pollution, yet the public consistently ranks the former as a much higher risk. Studies of risk perception have shown that the public response cannot simply be attributed to ignorance or to irrationality. Instead, there are a variety of dimensions to public risk perception that extend beyond that of the technical data. These include factors such as who is benefiting from the risk and whether the risk is familiar or unfamiliar, voluntary or involuntary, controllable or uncontrollable. The potential for catastrophe and the risk to children or to future generations also affects the extent of risk perceived by the public. There are also social, economic, and cultural dimensions to risk perception. For example, the risk of radionuclide contamination of salmon by atombomb production activities in the Columbia River Valley will be perceived differently by Native Americans, for whom salmon fishing is not simply a source of food but an integral part of their culture. Risk perception is thus not a straightforward probability calculation based upon exposure and dose-response measurements, but is complex, subjective, and value-laden. Effective risk communication requires the negotiation of a set of rules for each specific problem and with each specific public.
The theoretical basis for environmental risk communication arises in large part from advances in the understanding and the practice of public health education. A number of models have been developed for promoting the healthful behavior of individuals and communities. Classical diffusion theory, in which an expert resource system provides knowledge to a user community, is inadequate to explain the persistent gaps between experts and the public in the level of concern for different environmental threats. The health belief model, based upon stimulus-response and cognitive theories of behavior, explains behavioral change on the basis of patients' beliefs in their own susceptibility to a disease or condition. Under this model, the seemingly ubiquitous presence of environmental contaminants in air and water, and the possibility of serious and frightening endpoints such as cancer, lead to a high level of perceived threat. Control of these threats is accomplished through empowerment of the individual or community. Communications about risk are better understood in a context in which the hearer has the ability to control the risks and to make decisions about them. Social learning theory explains health behaviors in terms of a reciprocal determinism with personal factors and external influences, including physical and social influences. Emphasis is placed on the individual's locus of control and on observational learning as a means to develop behaviors and responses to potential threats.
Behavioral psychologists and others involved in environmental risk communication have employed and transcended health-education theory to provide many insights into the particular problems involved in environmental risk communication. A driving force in much of the research has been the "not in my backyard" (NIMBY) problem. This refers to the difficulty that government and industries have in siting any facility that seems to provide an environmental threat to the local public. NIMBY is not uncommon in other health-related circumstances, such as the siting of methadone clinics or halfway houses for those recovering from psychiatric illness. However, the depth of public opposition to environmental threats has been particularly effective in overturning siting plans based upon concerns that might otherwise seem irrational to experts in risk assessment and risk management.
Analysis of NIMBY and related situations has made it clear that trust is a factor of central importance in risk communication. The extent of distrust for institutions involved in environmental risk management has been strongly linked to the perception of high risks and to the willingness of
Efforts to improve risk communication have extended across multiple facets of the problem. Effective risk communication begins with getting the numbers right. As an example, in response to public concern about a perceived increased level of birth defects in a community, a state health department performed a risk assessment that led them to the reassuring statement that levels of birth defects were within the expected range. However, when a local citizens group was able to demonstrate that the health department's survey had missed at least a few cases of birth defects, further communications from the health department were not believed.
It is also of value to perform a risk characterization, the last formal step of a risk assessment, which can make a risk more understandable to the public. This includes abandoning the use of logarithms; providing information as to who is at risk under what circumstances; and, rather than as a numerical abstraction, expressing the risk in terms of the time period during which an additional adverse event would be expected to occur in a specific population. There is also general agreement that as part of a risk characterization the uncertainties inherent in a specific risk-assessment need to be explained to the public and to decision makers. But it is preferable that uncertainty be expressed descriptively and semi-quantitatively instead of by mathematical notation. As a general rule, an expert who takes the time to try to explain the meaning of a risk probability in lay terms will be able to communicate more believably, and hence more effectively. Similarly, effective risk communication may require the expert to focus on which of the many numbers sometimes generated in a risk assessment are most pertinent to the stakeholder. The source of information is also important, with academics generally ranking higher in credibility than industry or government experts.
Risk comparisons are often used in risk communication to fashion a conceptual metric stick for the stakeholder. It seems reasonable to compare a risk of a new technology or a pollutant to that of an existing risk, such as dying in an automobile accident. But, in fact, risk comparisons are highly problematic. Because they often seem unfair, they can lead to a loss in credibility of those who use them carelessly. Automobile travel is of value to the individual, while exposure from a chemical waste site or a new industry may be of no personal value whatsoever, except to those who expect to profit by it monetarily. Automobile travel is also voluntary, as is cigarette smoking, while exposure to toxic emissions is often unavoidably forced upon people. Further, most people do not believe that the statistical risk assigned to driving is pertinent because they drive safely as compared to "those other drivers." There are situations, however, in which a carefully chosen risk comparison can be helpful in communicating the extent of risk. A related approach is to compare the potential for risk reduction from alternative uses of the same expenditure, an approach that can be helpful if, in fact, the money can be moved among choices and the benefits can be accurately calculated.
In recent years the emphasis in risk communication has been on involvement of the stakeholders as early as possible in all of the steps of the risk analysis. Building on theoretical and practical advances in risk communication, the Presidential/Congressional Commission on Risk Assessment and Risk Management advocated stakeholder participation in the entire process of risk assessment and risk management. Their six-step framework begins with a first step of evaluating a risk problem in its local context, and continues through succeeding steps of risk assessment, presentation of options, making of decisions, performing actions, and evaluating outcomes. All of these steps are to be done in an open, transparent, and iterative process that involves stakeholders throughout.
Nevertheless, there are no simple and obvious approaches to successfully communicating technical information about risk to the public. Enhanced public education in science and technology would be helpful in the long term, but by itself is not a solution, as most of the problem lies with the communicators and with the inherent complexity of our modern society. Two "laws" seem to typify environmental risk communication to the community. The first concerns sincerity. If a government or industry has already made its risk-management decision, pretending that it is consulting with the community will lead to a backlash likely to prevent it from carrying forward the decision. The second law is that there are no applicable laws—each community is different, as is each risk situation. But there are general principles related to clarity,
The increasing international pressure for harmonizing risk-assessment processes, particularly in relation to trade issues, has led to a number of interesting efforts to understand apparent international differences in risk perception. For example, one contentious subject is whether the greater unwillingness of the European public to accept genetically modified food sources or beef from cattle previously treated with growth hormone represents a difference in risk perception, or is simply a means to erect a trade barrier against products from the United States. Understanding the broader cultural issues in risk perception and communication will be of importance in an increasingly globalized world.
BERNARD D. GOLDSTEIN
(SEE ALSO: Communication for Health; Communication Theory; Environmental Movement; Health Belief Model; Health Promotion and Education; Not In My Backyard [NIMBY]; Risk Assessment, Risk Management; Social Cognitive Theory)
Fischhoff, B. (1994). "Acceptable Risk: A Conceptual Proposal." Risk: Health, Safety and the Environment 5:1–28.
Goldstein, B. D., and Gotsch, A. R. (1994). "Risk Communication." In Clinical Occupational and Environmental Medicine. Orlando, FL: W. B. Saunders Company.
National Research Council (1989). Improving Risk Communication. Washington, DC: National Academy Press.
—— (1996). Understanding Risk-Informing Decisions in a Democratic Society. Washington, DC: National Academy Press.
Slovic, P. (1987). "Perception of Risk." Science 236:280–285.
Tinker, T. L.; Pavlova, M. T.; Gotsch, A. R.; and Arkin, E. B. (1998). Communicating Risk in a Changing World. Beverly Farms, MA: OEM Press.