Which is more of a threat to your health: Al Qaeda or the Department of Homeland Security?
An intriguing new study suggests the answer is not so clear-cut. Although it’s impossible to calculate the pain that terrorist attacks inflict on victims and society, when statisticians look at cold numbers, they have variously estimated the chances of the average person dying in America at the hands of international terrorists to be comparable to the risk of dying from eating peanuts, being struck by an asteroid or drowning in a toilet.
But worrying about terrorism could be taking a toll on the hearts of millions of Americans. The evidence, published last week in the Archives of General Psychiatry, comes from researchers who began tracking the health of a representative sample of more than 2,700 Americans before September 2001. After the attacks of Sept. 11, the scientists monitored people’s fears of terrorism over the next several years and found that the most fearful people were three to five times more likely than the rest to receive diagnoses of new cardiovascular ailments.
Almost all the people in the study lived outside New York or Washington and didn’t know any victims of the Sept. 11 attacks. But more than a 10th of them reported acute stress symptoms (like insomnia or nightmares) right after the attacks, and over the next three years more than 40 percent said they kept worrying about a terrorist attack affecting themselves or a family member.
Their worries were understandable, given the continual warnings from Washington. Officials repeatedly raised the color-coded level of the National Threat Advisory and sometimes explicitly warned of imminent attacks from terrorist cells supposedly operating in America. The alert level has never dropped below yellow (the third of the five levels). About a third to a half of Americans have continued to tell pollsters that they’re personally worried about being victims of a terrorist attack, and that an attack is somewhat or very likely within several months.
“It’s amazing how enduring these feelings of fear are, but look at what’s been going on,” said Alison Holman, a professor of nursing science at the University of California, Irvine, the lead author of the study. “I’d be surprised if those terrorist alerts didn’t contribute in some way to the ongoing worry about terrorism in our sample.”
Another of the authors, Roxane Cohen Silver, also at U.C. Irvine, is a psychologist who is on an advisory council to the Homeland Security Department.
“I’ve regularly pointed out to the department that there are psychological consequences to the raising of the alert,” Dr. Silver said. “Now we’re demonstrating that it may have physical consequences.”
The researchers caution that they’re not sure how serious the physical consequences are, because they’re relying on people reporting that their doctors have diagnosed new cardiovascular ailments. Also, studies like this show correlations, rather than an identifiable cause and effect. But since the researchers have taken into account reports of people’s health problems and anxiety that were collected before Sept. 11, and the levels of lifetime and continuing stress, they’re confident they’ve identified a worrisome increase in heart disease.
After controlling for various factors (age, obesity, smoking, other ailments and stressful life events), the researchers found that the people who were acutely stressed after the 9/11 attacks and continued to worry about terrorism — about 6 percent of the sample — were at least three times more likely than the others in the study to be given diagnoses of new heart problems.
If you extrapolate that percentage to the adult population of America, it works out to more than 10 million people. No one knows what fraction of them might consequently die of a stroke or heart attack — plenty of other factors affect heart disease — but if it were merely 0.0003 percent, that would be higher than the 9/11 death toll.
Of course, statistics of any sort, even when the numbers are rock solid, don’t mean much to people when they’re assessing threats. Risk researchers have found that even when people know the numbers, they’re less worried about death tolls than about how the deaths occur. They have good reasons — called “rival rationalities” — for fearing catastrophes that kill large numbers at once because these events affect the whole community and damage the social fabric.
