For years, Americans have been concerned about outdoor air pollution. So
concerned that, in 1990, Congress passed a thousand-page amendment to the
Clean Air Act to clean up the outdoor air-which will cost taxpayers about
$25 billion a year. Scientific evidence, however, suggests that indoor air
pollution poses a greater risk to people's health than outdoor air, says
John Graham, professor of policy and decision sciences at the School of
Public Health and director of the Harvard Center for Risk Analysis (HCRA).
Yet, he adds, there's no particular public demand for addressing indoor
air quality. "We live in a society that is both paranoid and neglectful
about dangers at the same time," he says.
Graham and his colleagues at HCRA are trying to promote a reasoned public
response to health, safety, and environmental hazards by encouraging rigorous
application of science-based risk assessment, risk-ranking methods, and
cost-benefit analysis. They routinely testify on regulatory reform before
committees in the U.S. House and Senate, they write articles for scientific
journals, and they publish Risk in Perspective, a newsletter mailed
to 14,000 opinion leaders, journalists, members of Congress, business executives,
and environmental advocates.
In 1994, Graham appeared on an ABC-TV program that discussed various fears
gripping America: fear of the food we eat, the water we drink, the air we
breathe. Fear of airplanes, power lines, cellular phones. "There are
real risks to worry about," said ABC reporter John Stossel, "but,
for the most part, we're worrying about the wrong ones." He pointed
out that when seven people died after ingesting tainted Tylenol, Americans
spent more than $1 billion sealing products in tamper-resistant packages.
Yet, he said, 50 children are killed every year by ordinary five-gallon
buckets. They fall into them and drown, but that doesn't make news because
buckets aren't new. "The mysterious, the bizarre, the speculative make
good news," Graham told Stossel. But common fatalities don't get attention
because the media don't have a hook to sell them.
Graham recently conducted a random survey of 1,000 Americans to identify
public perceptions of health hazards. Not surprisingly, the results suggest
that the greater the number of national news stories about a hazard, the
more likely the public is to believe that it is real (see the quiz, next
page). The most interesting finding, however, is a large gender gap, says
Graham. Even after controlling for such variables as educational background
and values, women are much more likely than men to believe that something
is dangerous. For example, 68 percent of the women surveyed-but only 50
percent of the men-considered pesticide residues on fruits and vegetables
a health risk.
Graham and his colleagues are now comparing results from their first survey
with a similar poll of scientific experts. A disturbing finding, Graham
says, is that lay people tend to evaluate ionizing radiation-from radon
in their homes or from medical x-rays-as almost the same as nonionizing
radiation, like electric and magnetic fields from power lines or cellular
phones. (The scientific evidence for danger from ionizing radiation is much
stronger.) Such discoveries have implications for how reporters need to
interpret health information for ordinary citizens.
James Hammitt '78, M.P.P. '81, Ph.D. '88, associate professor of health
policy and management, chides journalists for failing to give the public
a sense of the relative probability of harm. "People think that rare
events are much more common than they are," he says. A catastrophe
like this spring's ValuJet crash, for instance, garners more press attention
than car accidents, even though people are much more likely to be killed
or injured on highways than in airline travel. (For a 1,000-mile trip, flying
on a commercially scheduled jet airliner is about 10 times safer, in terms
of fatalities, than driving a car.)
Government agencies like the FDA also mislead the public, says Graham. "There've
been studies of large populations of women who have had breast implants
for years, comparing them with women who have not," he says. "We've
looked at the symptoms reported, and they aren't any more frequent among
women with breast implants. But it's very difficult for the government to
turn around and say, 'Oops, we were wrong. Breast implants aren't hazardous.'
Don't hold your breath until that happens."
Graham says there is evidence that if people are unfamiliar with a technology,
they will be more concerned about its dangers. For example, lay people may
not understand a nuclear power plant, and that will increase their level
of concern. But they think they understand an automobile, so even though
it's potentially dangerous, they're not so worried about it. "If people
react too much on that principle, they can suffer from this syndrome of
being paranoid and neglectful," Graham says. "If we focus our
resources on what's scary, rather than on what kills people, in the process
we may end up committing a form of statistical murder."
