Risky business - health risks; includes related information

Risky Business

As I was on my way in to work this morning, a homeless man asked me for a quarter. I told him I didn't have any change, but that he could have the apple I was planning to eat with my lunch.

"No way, lady," he said. "That might have Alar in it. Don't you know how bad Alar is?"

I didn't tell him that I was writing an article on risk, and that Alar was very much on my mind. And, anyway, what would I have said?

What should I have told that homeless man who was afraid to eat the apple I offered him?

I could have said, "Don't worry. You should eat the apple." After all, the Environmental Protection Agency (EPA) estimates that lifetime exposure to Alar increases a person's risk of dying of cancer by up to 45 ten-thousandths of one percent (0.000045). And that risk pales next to the risks from smoking, eating a high-fat diet, or excessive alcohol consumption.

I just as easily could have said, "You're right to worry about Alar." After all, according to EPA estimates, continued exposure to the pesticide could cause nearly 11,000 additional cancer deaths by the year 2033.

In other words, I could have told him that the same risk that posed a pretty small danger to one person could result in thousands of deaths in a population as large as the United States.

I also could have told him that no matter what he decides to do about his risk, what we all should do is demand that the government deal with the risk to society.

But I didn't tell him anything. I was in a hurry to get to the office to finish this article. What to Do. What should you do about pesticides and additives?

The simplest solution is to avoid them, to buy as much organic and minimally processed food as you can. After all: Why endanger your health, even slightly, if you don't have to?

At the same time, you should demand that the government save thousands of lives by protecting us from these substances. But don't hold your breath.

Until you can convince Washington or your state legislators to do something, you'd be smart to learn as much about risk as you can. You need to understand what the experts can tell you, the importance of what they don't tell you, and how you're influenced by the way they tell you. If Statistics Ruled. Thinking about risk seems relatively straightforward. Just rank the risks in order of which are most likely to kill you, and avoid those highest on the list.

Bernard Cohen, a physicist at the University of Pittsburgh, did just that. He calculated the days of "life expectancy reduction" (LER) from different causes. The higher the LER, the higher the risk.

Topping Cohen's risk list was being unmarried (LER = 3,500 days for males, 1,600 days for females), cigarette smoking (2,250 days for males, 800 days for females), and heart disease (2,100 days). These risks dwarfed most others, like dying in a car accident (207 days), or drinking a saccharin-sweetened soft drink every day (2 days).(1)

Does that mean bachelors should rush out and get married? Or that you shouldn't worry about artificial sweeteners?

No, and for good reasons. Risk is More Than Hazard. Science isn't everything when it comes to risk. To most of us (including scientists on their days off) risk is also defined by ethical, psychological, and other "outrage" factors.(2,3) * Voluntariness: As Peter Sandman, of Rutgers University, points out, "Consider the difference between getting pushed down a mountain on slippery sticks and deciding to go skiing." * Fairness: Residents of a community "chosen" to handle other people's hazardous waste feel incensed, even if the danger is small. Why should they bear the risks and get no benefits? * Control: Most adults feel safer driving a car than being driven. * Trustworthiness of the source: Which risk estimate for a food additive are you more likely to believe: one prepared by the manufacturer, or one prepared by an independent university scientist? * Newness: When microwave ovens were first introduced, people viewed them as far riskier than they do now. * Catastrophic potential: What's worse: a disease that has a 1-in-10 chance of obliterating a town of 1,000 people sometime during the next ten years, or a disease that is expected to cause ten deaths each year for ten years? To a statistician, there's no difference. * Dread: Although heart disease is the most common cause of death in the United States, people seem to be much more afraid of dying of cancer.

These "outrage" factors may be less tangible and harder to calculate, but they're just as important as the scientists' numbers. Yet government regulators and risk experts tend to ignore them.

Biochemist Bruce Ames, of the University of California at Berkeley, argues that we shouldn't worry about pesticides because "naturally" occurring carcinogens in foods pose cancer risks thousands of times greater.

"Even if he's right--and it's debatable--his argument is beside the point," counters biologist Edward Groth III, of Consumers Union. "Nature may not be benign, but She's blameless. She's not making a business decision to sell of spray Alar, while someone else bears the risk." Risk is More Than A Number. We'd be foolish to ignore what scientists say about risk, since we lack the time and expertise to evaluate the studies ourselves. But we'd also be foolish to treat the experts' pronouncements as gospel. Here's why: * Once scientists calculate a risk number, all the assumptions that went into the calculation are easily forgotten, and the number takes on a life of its own. * Scientists haven't even identified all the chemicals in our diet, much less studied their adverse effects or calculated their risk.

For example, chemicals called heterocyclic amines (HAs), which are found in fried meats, are suspected of causing cancer. "every one tested so far has been carcinogenic," says Dr. Frederick Hatch, of the Lawrence Livermore Laboratory in California. But the tests weren't comprehensive enough to put a number on the risk. And many other HAs have yet to be identified, while still others are waiting to be tested. * Risk estimates for a single chemical don't cover how it may interact with other substances we are exposed to. For example: As far as damage to your liver is concerned, exposure to alcohol and carbon tetrachloride is not like 1 + 1 = 2. It's more like 1 + 1 = 4. * Eating one additive or contaminant will increase your personal risk only a tiny amount. But no one knows the risk from all of them combined. * Risk estimates for pesticides and food additives usually measure how they affect our bodies, but not how they affect the environment, or how they affect a mother who learns that she may have fed her children cancer-causing pesticides along with their apple juice. * Experts (as well as the rest of us) tend to be overly confident about what they know. Remember how a nuclear accident like the one at Three Mile Island was "impossible"? * Using healthy animals to represent the wide range of human susceptibility has its problems. In most cases, though, it may be the best--or only--method available. Risk Perspectives. If all that mattered were the numbers, then you should be nearly 400 times more worried about being killed in a car accident than dying from cancer caused by Alar, at least according to the EPA's estimate. But statistics alone don't--and shouldn't--rule.

The risk to society from Alar and most other pesticides and additives is not acceptable. We should let the government know that we are "outraged" by the continued use of unnecessary chemicals.

(1)Health Physics 36: 707, 1979. (2)Science 236: 280, 1987 (3)EPA J. 13(9): 21, 1987.

COPYRIGHT 1989 Center for Science in the Public Interest
COPYRIGHT 2004 Gale Group