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Risk Communication

Risk Communication and People's Perception of Risk

By David F. Gallup, Co-founder of EMLab P&K

It is readily apparent that the world is preparing for the next pandemic of influenza. In the United States, the Centers for Disease Control and Prevention (CDC) has estimated that if the next pandemic is as severe as the 1918 pandemic, then approximately 2 million Americans could die.1 The 1918 pandemic is felt to have resulted in the deaths of 50 to 100 million people worldwide, or roughly 3 to 6 percent of the world population.2 It is also felt that these numbers would have been larger if nonpharmaceutical interventions (NPIs) had not been employed. These interventions included what we now call risk communication, a method the CDC is actively using to help minimize the effects of the flu season this year.

The CDC defines crisis and emergency risk communication as: "The attempt by science- or public-health professionals to provide information that allows an individual, stakeholders, or an entire community to make the best possible decisions during a crisis emergency about their well-being, and communicate those decisions, within nearly impossible time constraints, and ultimately, to accept the imperfect nature of choices as the situation evolves."3 An alternative definition is "To effectively provide, in a manner that can be processed cognitively and without emotion, the relevant data to enable the recipient(s) to make informed decisions that leave them with the best odds of the most positive outcome and no regret." Risk communication serves to maximize the health and well-being of the population, provides mechanisms to help people decide the appropriate level of treatment that they need, and ensures that limited resources are efficiently directed to where they are needed most.4

While the CDC obviously deals with a dramatically different scale and scope than most indoor air quality investigations, risk communication can still be a useful tool. Biological agents in particular meet many of the criteria that increase people's perception of risk. They are often perceived to be exotic, involuntary, catastrophic, outside of one's control, and without benefit.

Predictably, perception of risk is often flawed. In 2007, many people were more concerned about the West Nile virus (WNV) than they were about influenza (not the recent H1N1 concern, but 'normal' seasonal influenza). How did this compare with actual risk? In the United States, in 2007, there were 3,630 cases of WNV and 124 deaths, (a 3.4% fatality rate).5 Although it is difficult to find comparable simple data for flu, there are readily available statistics to develop a perspective. There were 39,827 specimens that tested positive for the flu in the US during the 2007-2008 flu season. The percent of outpatient visits associated with influenza peaked at 6% in February and mortality attributed to pneumonia and influenza peaked at 9.1% during the week ending March 15, 2008.6 The point here is not to comment on the severity nor the risks associated with these illnesses, but rather to illustrate the gap between perceived and actual risk. John Paling from the Risk Communication Institute said, "Fear is such a powerful emotion that it can easily overwhelm what the facts show." A simple observation of our modern media, advertisements, and political debates will show that fear is a tool that is frequently used to effect people's behavior. (Unfortunately, in many of these examples, it is with manipulative intent.)

What impacts people's perception of risk? Here is a list of some primary factors influencing people's perceptions of the magnitude of risk.7

  • Risks perceived to be familiar are more accepted than risks perceived to be exotic.
  • Risks perceived to be voluntary are more accepted than risks perceived to be imposed.
  • Risks perceived to be under an individual's control are more accepted than risks perceived to be controlled by others.
  • Risks perceived to have clear benefits are more accepted than risks perceived to have little or no benefit.
  • Risks perceived to be fairly distributed are more accepted than risks perceived to be unfairly distributed.
  • Risks perceived to be natural are more accepted than risks perceived to be manmade.
  • Risks perceived to be statistical are more accepted than risks perceived to be catastrophic.
  • Risks perceived to be generated by a trusted source are more accepted than risks perceived to be generated by an untrusted source.
  • Risks perceived to affect adults are more accepted than risks perceived to affect children.

So what? What do we do with this information? Understanding these factors can shape the message we are trying to communicate. Part of our objective is to pull emotion out of the decision and enable people to make informed, unemotional decisions. If we review the list above, we may decide that we can help a particular client by providing information that makes mold less exotic by framing it in the context of other more familiar risks, or we may decide that they may feel better if they realize that by controlling the moisture they do, in fact, have control over the mold. Understanding risk communication may identify possible methods to deliver information in a manner that is beneficial to our clients.

More generally, Vincent Covello and Frederick Allen have studied risk communication and outline seven principles of risk communication8. These are:

  1. Accept and involve the public as a legitimate partner.
  2. Plan carefully and evaluate your efforts.
  3. Listen to the public's specific concerns.
  4. Be honest, frank, and open.
  5. Coordinate and collaborate with other credible sources.
  6. Meet the needs of the media.
  7. Speak clearly and with compassion.

Most of these can be simplify modified or applied directly to IAQ investigations. Similar recommendations come from other sources. John Paling said "When it comes to effectively communicating the risks, a bond of partnership, a feeling of trust and an empathetic approach are every bit as important as the numbers." The FDA, who like the CDC, is frequently called upon to communicate risk to the public, states the belief that risk communication should be science based, cognitively accessible to the audience, and relevant to the decision at hand. Further, such communication needs to provide context and be adapted to the audience's needs which will be highly variable from case to case.

Each situation will have different constraints and call for its' own approach. Some will require great consideration and planning, others will not. In general, however, taking the time to think through how to effectively communicate the relevant data to the involved parties will likely help both you and your client.

1. CDC Public Affairs in Health: Crisis and Emergency Risk Communication: Bandura's Social Cognitive Theory and Pandemic Influenza Response
2. Wikipedia: 1918 flu pandemic
3. CDC's Crisis and Emergency Risk Communication, September 2002
4. Massachusetts State Government: Risk Communication in Public Health
5. Wikipedia: West Nile virus
6. CDC: Influenza Activity – United States and Worldwide, 2007-2008 Season
7. DHHS: Risk Communication: Working With Individuals and Communities To Weigh the Odds
8. Ibid

Additional Resources:
Many situations have their own constraints and may not fall into a template or technique that has been developed by others. Still, the resources below may have ideas, techniques, or elements that may be helpful to your particular situation.
• Broad set of guidelines and suggestions: The Risk Communication Institute
• FDA: Strategic Plan for Risk Communication
• Massachusetts State Government: Risk Communication Plan Template (pdf)


This article was originally published on October 2009.