新编大学英语第二册unit10 Text B: Health Risks
UNIT 10 AFTER-CLASS READING 1; New College English (II)
Health Risks
1 Opinion polls repeatedly tell us that the only thing Americans worry about more than the environment is their health. This is entirely understandable, for health is obviously preferable to illness. What makes today's preoccupation with health slightly surprising is that Americans are far healthier now than they have ever been. Many diseases that once struck terror into hearts have either been completely eliminated or brought under control. Although AIDS is a notable exception, few new mass killers have come along to replace the ones that have been eliminated.
2 Nonetheless, health and the various threats to it remains everyone's permanent concern. After all, more than half of us (57 percent) will die from either heart disease or cancer, if current trends continue.
3 One major problem with any comparison of health risks especially life-threatening ones is that they differ enormously in their immediacy. For instance, AIDS if you get it will probably be fatal after a number of years. Cancer induced by smoking or exposure to radiation, on the other hand, may take 20 to 30 years before its catastrophic effects show up. In making choices about health risks, therefore, it is important to bear in mind the likely time lag between taking a risk and suffering its consequences.
4 Those with a mind to "live for today" are apt to be indifferent to health risks that have a very long incubation period. Although this is short-sighted, it does make sense to discount long-term risks more than short-term ones. After all, when virtually any of us is confronted with the choice of doing something likely to kill us today versus doing something likely to kill us in two decades, the choice is going to be the lesser of the two evils.
5 One commonly used measure to deal with such problems is a concept called years of potential life lost (YPLL). The idea is that for a 25-year-old, doing something that will kill him in 5 years is much more "costly" than doing something that will kill him in 40 years. Both may involve the same element of risk the same probability of eventually dying from that activity but a risk that may cause immediate damage is much more costly than one for which the piper needn't be paid for a long time. In the first case, he will have his normal life span cut short by about 45 years; in the latter case, the deficit is about 5 years. Thinking about matters in this light inevitably causes a reassessment of many of the threats to health. For instance, heart disease is the single largest killer of Americans, way in front of cancer or strokes. However, heart disease tends to strike the elderly in much greater proportions than younger people. Cancer, by contrast, kills fewer people but tends to strike somewhat earlier than heart disease. Hence, more YPLLs are lost to cancer than to heart disease despite the greater incidence of fatal heart cases. Specifically, cancers claim about 25 percent more YPLLs than heart disease (if we define the YPLL as a year of life lost before age 65).
6 The concept of YPLLs has an important, if controversial, influence on issues in health care economics. It is frequently argued that money devoted to medical research on curing diseases should be divided up on the basis of the number of lives lost to each disease. Thus, some critics of the massive levels of funding devoted to AIDS research claim that compared to killers such as heart disease and cancer AIDS receives a disproportionately high support. That criticism fails to consider the fact that AIDS, by virtue of striking people principally in their 20s and 30s, generates far more YPLLs than the bare figure of 20,000 deaths per year, bad as that is, might suggest. 10 Put differently, finding a cure for AIDS would be likely to add about 25 to 30 years to the life of each potential victim. Finding a cure for heart disease, although it might save far more lives, would probably add only another 5 to 10 years to the life of its average victim.
7 The assessment of the seriousness of a risk changes, depending upon whether we ask how many lives it claims or how many YPLLs it involves. Some of the differences are quite striking. For instance, accidental deaths appear relatively insignificant compared to cancer and heart disease when we just count the deaths caused. But once we look at the number of lost years, accidents loom into first place among the killers of Americans. These data show that we need to ask not only how large a risk is but also when it becomes payable. Other things being equal, the sooner a risk causes damage or death, the more that risk is to be avoided.
