SCIENCE / MEDICINE : Scientists and the Public Diverge on Perceptions of the Risks of Modern Life : Health: Specialists offer a ‘worry guide’ for the 1990s and outline what people can do to keep themselves well.

“It is the safest of times, it is the riskiest of times . . . . What the dickens is going on here?” asked Michigan State University sociologist Denton Morrison in an essay titled “A Tale of Two Toxicities.”

The seeming contradiction is a “major technological paradox of our time,” said Morrison, and it emerges from growing differences in the way experts and the public perceive risk.

A recent National Academy of Sciences report, “Improving Risk Communication,” cited Morrison’s paradox as the “central dispute about technology and risk.” Those who believe it is the safest of times point out that average life expectancy has risen at a time when the nation increased its use of chemicals and other hazardous substances. Those who view this as the riskiest of times say modern technology is generating new threats to society and the Earth’s life-support systems at an accelerating pace.

The academy report concluded that “the dispute cannot be resolved by available evidence. In fact, it may not be about evidence. At a deeper level, it is about what kinds of risks people want most to avoid, what kinds of lives they want to lead, what they believe the future will bring.”

The 1980s brought an array of highly publicized risk concerns: AIDS, second-hand cigarette smoke, the Soviet nuclear accident at Chernobyl, radon and indoor air pollution, medical-waste disposal, toxic waste dumps, cholesterol, Alar in apples, warnings about destruction of the Earth’s ozone layer and concern about global warming.

The challenge for the 1990s may be to decide what to worry about, which risks are acceptable and which are intolerable, whether they can be prevented and at what cost.

“We worry so much we are almost afraid of our own shadows,” said James O. Mason, assistant secretary for health in the Department of Health and Human Services. “Identify the risks that are really significant and do something about those.”

Here’s a “worry guide” to the 1990s from some of the nation’s top health experts:

* Personal health habits. The cartoon character Pogo’s dictum, “We have met the enemy and he is us,” will continue to be painfully true in terms of personal health risks.

A study for the Carter Center of Emory University in Atlanta estimated that two out of three deaths in this country and one out of three hospitalizations are linked to only six risk factors: tobacco, alcohol, injuries, high blood pressure, diet (too many calories, too much fat and cholesterol), and gaps in basic health care.

“What I think will be most important in the 1990s will be a growing awareness of how many of the risks we bring on ourselves we in fact can control. I’m talking about tobacco, drinking and driving, drug use of all kinds, the way we eat, the way we live our lives in terms of stress and fitness,” said Harvey V. Fineberg, dean of Harvard’s School of Public Health.

Changes in lifestyle are already credited with a dramatic decline in the nation’s No. 1 killer, heart disease. “For people to worry about their health risks is an investment for their future,” said Claude Lenfant, director of the National Heart, Lung and Blood Institute. “I cannot change how I am born, but I can change what I do in terms of blood pressure, smoking, general fitness, exercising, taking care of my body.”

For the No. 2 killer--cancer--”put smoking as a very high priority,” said National Cancer Institute chief Samuel Broder. “We’re losing ground in some areas, particularly adolescents and women. Smoking is also having a resurgence in underserved, poor populations.” Health officials believe that about one-third of cancers are related to smoking. One-third are linked to dietary influences, probably high fat and low fiber. The other third are open for discussion.

Risks also vary at different ages, with younger Americans most threatened by injuries--from automobiles to handguns--and new diseases like AIDS. At the other end of the spectrum, Americans are at risk of many chronic disabilities that make them unable to function on their own.

* Environmental risk. There is less agreement on which environmental risks are most important. Many public-health experts feel the public’s concern about chemicals and cancer is out of proportion to the actual risk.

“Environmental and toxic agents need to be watched, but are not imposing the kind of health burden that the behavioral risks are,” said Michael McGinnis, deputy assistant secretary for health at the Department of Health and Human Services.

Meanwhile, environmental scientists are moving toward the notion of acceptable risk. “Exposure to some environmental material might be capable of causing disease, but the likelihood could be vanishingly small,” said Samuel Thier, head of the National Academy of Science’s Institute of Medicine. “The fact that something has a finite risk doesn’t mean that it is unacceptable.”

In 1987, an Environmental Protection Agency task force ranked pesticides, air pollution, radon and other indoor air pollution, tap water, consumer product exposure, worker exposure to chemicals and global warming at the higher end of environmental risks to health and ecology. But the public was more concerned about hazardous- or toxic-waste sites and chemical plant accidents, which ranked lower in the task force’s view.

At the same time, many scientists and consumer advocates are concerned that there have not been enough studies of the more subtle and long-term effects of exposure to chemicals. Lead poisoning from paint, drinking water and urban dust and soil that is now recognized as a cause of irreversible brain damage and other brain defects is one example.

“We’re always playing catch-up with chemicals in the environment. If I had one wish, it’s that we really made a serious commitment to testing chemicals before we start using them,” said Ellen Silbergeld, director of the Environmental Defense Fund’s toxic chemicals program.

Researchers are also recognizing that there are other important health effects besides cancer, such as risks to the nervous system, lungs, kidneys and fetus. “We’ve got to take into account real differences in susceptibility among individuals and learn to detect them,” said Gilbert Omenn, dean of the University of Washington School of Public Health and Community Medicine.

* Societal risk. Some of the most difficult health risks are posed by American society itself. The way the country educates its children, addresses the problems of inner-city poor and minority communities and provides health care are major social challenges for the coming decade.

Public health is expanding to include problems like violence, poverty and education that go beyond medical care.

“There are a whole lot of health effects related to social characteristics, like inadequate education, income, housing, transportation, welfare, retirement,” said Alvin Tarlov, president of the Henry J. Kaiser Family Foundation. “I would say a buck spent on improving public school education probably would do more for health than a buck spent on medical care. The most powerful correlate of good or bad health is the level of education. There is a direct relationship between health and education as measured in infant mortality, maternal mortality, heart disease, substance abuse and adolescent pregnancy.”