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Abstract
When a major, unpredicted catastrophe or attack occurs, there is a greater awareness of the riskiness of life and the prevalence of uncertainty. The field of risk analysis is devoted to attempting to quantify risks and uncertainties - trying to predict, in essence, when and how often Murphy's law (or other malicious agents) will strike.
| Risk analysis involves assessing, managing, and communicating risks. |
"Risk analysis includes risk assessment, risk management, and risk communication," says George Gray, acting director of the Harvard Center for Risk Analysis. Though many professionals are involved in all three areas, the expanding field of risk analysis is becoming increasingly specialized.
John Ahearne, president of the Society for Risk Analysis and adjunct professor of civil and environmental engineering at Duke University, says, "We have about 5,000 members, and I would guess that there are about 10 to 20 thousand people who, in part of their work, have to do risk analysis. The field is growing, our membership is growing, attendance at meetings is growing, and the number of journals devoted to risk issues is growing."
| The U.S. government originated scientific risk analysis. |
Risk analysis as a scientific specialty (excluding financial risk analysis) developed in the United States as the federal government became interested in regulating potentially risky substances and improving military capability. Some experts say that the Food and Drug Administration introduced risk analysis in the 1950s when it first tried to determine safe levels of substances to be allowed in food; others point to the passage of the National Environmental Policy Act in 1970, which required all federal agencies to do environmental impact statements.
Ahearne, a physicist who spent much of his early career in the military says, "I was in the Air Force working on issues related to the use of weapons and then in the Pentagon. When I was first doing it [in the 1960s], the term risk analysis wasn't around. It was called operations research."
| The Rasmussen Report was a major turning point. |
The experts agree that a major turning point in the field was the release, in 1974, of the Rasmussen Report. This paper analyzed nuclear power plants in a new way - using a technique called probabilistic risk analysis (PRA) (in Europe, probabilistic safety analysis). Previously, risk analyses had been deterministic - they didn't include calculations to weigh which errors were most and least likely to occur in their assessments of potential safety problems.
When the Three Mile Island nuclear accident occurred in 1979, the problem that caused it was the one that the Rasmussen Report predicted would be most likely to occur. "Engineers were uncomfortable with probability [analyses]," says Ahearne. "It almost took a new generation to accept PRA. It took the U.S. Nuclear Regulatory Commission 10 years to accept it."
| Three Mile Island was a test case for PRA. |
The Three Mile Island accident also helped workers in risk analysis recognize another area that was important - risk perception and psychology. "There were a whole succession of failures of technology and expertise," says Baruch Fischhoff, university professor of social and decision sciences at Carnegie-Mellon University, "The Vietnam War, Silent Spring, Three Mile Island, all eroded confidence in experts. As experts were pressed, [the public found out that] the science was narrower than the experts had claimed and had not looked at the full spectrum of risk."
Psychologists found that experts and lay people had very different ideas about risk, and, early on, ordinary people's fears about risks were dismissed as irrational. As risk analysis developed, however, people in the field began to recognize that perception of risk mattered and that things such as the level of uncertainty, the level of control people have over risk, and whether or not damage from a risk was irreversible all needed to be taken into account.
| "Recognition of the role of psychology came from two directions." |
"The recognition of the role of psychology came from two directions," says Fischhoff. "One was the recognition of the need to include the public in decisions about technology, whether it be medicine or nuclear power plants, and the second was the recognition of the need to consider the psychology of the experts. The technical people were pushing their values into the definitions of the problem."
The researchers in this field attacked the issue from both sides - creating a specialty in risk communication, aimed at helping the public understand risks and also trying to make the values part of the analyses explicit, particularly when including costs and benefits.
| "We could have a five-mile-an-hour speed limit." |
"We could have a five-mile-an-hour speed limit," says Gray, giving an example. "We wouldn't have 40,000 road deaths a year. Benefit/cost analysis attempts to say, when choosing to regulate, is the benefit worth the cost? We make these decisions all the time. What benefit/cost analysis is arguing is that we should [make these values decisions] explicitly."
"[There is] a tension in the field," Gray adds, explaining that the fears of the public must be taken into account, but that weighing them too heavily could lead to expensive measures to reduce small risks, leaving little money for dealing with more dangerous problems. "John Graham [former director of the Harvard Center for Risk Analysis, now chief reviewer of regulations for the Office of Management and Budget in the Bush administration] calls it 'statistical murder.' If you are not putting your money in the most effective place, you are hurting people."
| "Some say risk analysis can't include basic values like fairness." |
Some opponents of the use of risk analysis for regulation, however, say that using it doesn't give enough importance to values like saving the environment for its own sake - or to the question of equity. "Some say risk analysis can't include basic values like fairness," says Ahearne, giving the example of a poor community overloaded with industrial waste sites. Adding another waste site might not add significant risk to those living in the area, but it also wouldn't necessarily be fair.
Risk arguments are also often used to present "scientific" reasons for policies - for example, the idea that marijuana is illegal because it is more dangerous than legal drugs or activities. "That's an example of a situation in which a values argument is couched and hidden in a risk argument." says Gray.
| Wilde wondered why seat belts didn't decrease deaths. |
In psychology, those who study risk are developing new ideas about how people respond to risk and control it in their own lives. Gerald Wilde, professor of psychology at Queen's University in Kingston, Ontario, was studying measures to reduce the risk of car accidents in 1972, and the data seemed to make little sense. For example, although the death rate per mile driven seemed to drop when safety measures like seat-belt wearing were promoted, the death rate per capita remained remarkably steady.
"I hit on the idea that it was a closed loop control process. If change is brought about, drivers readjust their behavior," says Wilde. In other words, people are willing to take a certain amount of risk while driving, so if you make driving safer, they will drive more or drive faster to return to this risk level. Wilde waited 10 years after developing this notion of "risk homeostasis" to accumulate evidence for it. In 1982, when Risk Analysis published his paper, the entire journal was devoted to a discussion of it. The implications for controlling risk taking are broad - if you want to reduce actual death rates from risky behavior, you either have to provide incentives for safe behavior or make people want to live longer because people who care about the future are more cautious.
| Evidence from traffic research supports Wilde's theory. |
Evidence from traffic research supports Wilde's idea. For example, an experiment done in California in the 1970s found that a promotion offering free license renewal to drivers if they had no accidents for a year reduced accident rates by 22 percent in the first year and 33 percent in the second. Wilde's ideas are still controversial with many in the public health community, but there is a growing acceptance of them in the risk field.
So how would someone interested in risk analysis become involved in this varied field?
The Harvard Center for Risk Analysis, which is associated with the Harvard School of Public Health, offers programs in environmental science and risk management at both the master's and Sci.D. level. Some other top programs are at Carnegie-Mellon and Stanford. The University of Oregon at Eugene is known for its program in the psychology of risk. Classes and concentrations in risk management can be found in engineering schools, business schools, psychology departments, and schools of public health.
| "Physics is great training because physicists can learn anything." |
Says Ahearne, "Course work should lead to analytical thinking, not a broad, subjective sketch. Technical or even legal training is helpful. If you want to go into technology, then engineering is appropriate, with health risks, chemistry, biology, and other life sciences." He adds (as a physicist), "Physics is great training because physicists can learn anything."
Gray says, "If possible, find an opportunity to cross-train, to understand the quantitative side, the scientific side, and the psychological side. The other option is to become very well grounded in one discipline and either through education or work experience get exposure to another."
| The risk community can contribute to the dialogue on terror. |
The recent terrorist attacks in the United States have generated new interest in understanding how to reduce security risks - though all the analysts interviewed for this article said that the risk, for example, of being hijacked while flying now is still extremely low. Ahearne says, "A lot of people in the risk community are trying to think this through to see what we can contribute to the dialogue on terror."
Maia Szalavitz is a health/science journalist who has written for the New York Times, the Washington Post, Newsday, New York Magazine, Salon, and other major publications.
Susan Wolsborn is Web designer of HMS Beagle.
Society for Risk Analysis - the major professional organization of risk assessors. The site lists job opportunities, news, events, and extensive links.
RiskWorld - covers news and views on risk assessment. The site lists risk assessment courses and publishes abstracts from the latest research in risk assessment/toxicology.
Superfund Today: What Is Risk Assessment? - a good review of the field. Presents a case study.
What Is Risk? - an accessible tutorial. From the U.S. Department of Energy's Center for Risk Excellence.
Office of Science and Risk Policy - provides federal policy information on risk assessment. From the U.S. Department of Energy.
Risk Assessment and Policy Association - an international organization focusing on several aspects of risk assessment, including the role of risk analysis in decision making.
Harvard Center for Risk Analysis - created in 1989 to promote reasoned public responses to health, safety, and environmental hazards.
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