The ability to communicate effectively the degree or magnitude of public exposures or health risks is essential for risk assessors and risk managers. Various guidelines exist for communicating environmental and public health risks, including recommended approaches for putting risk data into proper context. Although it remains unclear as to which approach is the most useful or appropriate under different circumstances, risk comparisons are a popular choice for conveying the significance of or providing a better perspective on a particular chemical exposure or health risk. In this paper, several different types of risk comparisons are described that are frequently used in the private and public sectors, and these are illustrated using a variety of examples from the literature. These approaches include: (1) intrachemical comparisons, (2) interchemical comparisons, (3) comparisons to background levels of risk, (4) comparisons to theoretical risks or safety levels, and (5) comparisons to other actions or activities. The primary purpose of this paper is to summarize and briefly discuss the advantages and limitations of these risk communication approaches. The evolving field of risk communication is also discussed, including ongoing research on public risk perceptions and alternative methods for communicating risk magnitudes and data uncertainties.
Journal of Exposure Analysis and Environmental Epidemiology
IntroductionThe ability to communicate effectively the degree or magnitude of public exposures or health risks is essential for risk assessors and risk managers (Williams, 2000). Risk communication is the process of conveying information about an exposure, risk, or risk management decision (NRC, 1989). More specifically, risk communication can be defined as ''any public or private communication that informs individuals about the existence, nature, severity, or acceptability of risks '' (Plough and Krimsky, 1987). Communicating risks often involves interpreting available scientific evidence, and describing and summarizing scientific knowledge about exposure and risk issues (NRC, 1989). Risk communication can also be used to influence public opinion or choice, or to arouse or alleviate public concerns about a risk issue (Kasperson et al., 1988;Sandman, 1993). The history of risk communication as applied to environmental and public health risks has not been fully documented, but has clearly evolved through several developmental stages over time (Fischhoff, 1995) and may have been influenced by the desire to gain acceptance for decisions grounded in risk assessment methods (Plough and Krimsky, 1987) or the organizational adaptation of chemical manufacturers to external pressures (Chess, 2001).Over the last 20 years, various guidelines have been published for communicating environmental and public health risks. For example, the Agency for Toxic Substances and Disease Registry (ATSDR) has produced several risk communication reports and case studies as part of their mission to explain the public health hazards associated...