Environmental Engineering Reference
In-Depth Information
TABLE 2.2 Increase in Life Expectancy between 1900 and 1990 at Selected
Ages, U.S. Total Population
Life Expectancy
1900
a
2004
b
Age
Gain During 1900 -2004
0 49.2 77.8 28.6
1 55.2 77.4 22.2
5 55.0 73.5 18.5
15 46.8 63.6 16.8
25 39.1 54.0 14.9
35 31.9 44.5 12.6
45 24.8 35.3 10.5
55 17.9 26.6 8.7
60 14.8 22.5 7.7
65 11.9 18.7 6.8
70 9.3 15.1 5.8
75 7.1 11.9 4.8
80 — 9.1 —
85 — 6.8 —
a
Department of Commerce, U.S. Census Bureau,
United States Life Tables 1890, 1901, 1910,
and 1901- 1910
, by J. W. Glover, U.S. Government Printing Office, Washington, DC, 1921,
pp. 52 - 53.
b
National Center for Health Statistics, Centers for Disease Control and Prevention.
National
Vital Statistics Report, Deaths: Final Data for 2004
, Vol. 55(9), August 2007.
one-sixth of all deaths, and the life expectancy increased by one-sixth. But this
would hold true only for a population with homogeneous individual risks for
cancer (ref. 13, p. 954): “Only in such a population would the reduction of
the deaths and of the death rate by one-sixth extend the expectation of life by
one-sixth. Only then could each of us expect to live 12 more years (assuming a
life expectancy of 72 years) as a result of the discovery of a cure for cancer.”
But because the population is not homogeneous and the risk factors for cancer,
and other diseases, vary with age [such as for a 20-year-old man (1: 10,000)
compared to a 70-year-old man (1: 100)], the “universal elimination of cancer
would increase life expectancy by only about 2 years — not the 12 years that
would apply if the population were homogeneous” (ref. 13, p. 955). Keyfitz
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goes on to say, “But even the gain so calculated (two years if cancer is eliminated)
is almost certainly an overestimate of the benefit. For within any given age group,
the people subject to any one ailment tend to have higher than average risks
from other ailments” (p. 955). To extend average life expectancy beyond 70
years, Keyfitz feels it is necessary to focus on prevention of “deterioration and
senescence of the cells of the human body” (p. 956).
Taeuber
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estimates that the life expectancy of a 65-year-old man would be
increased by 1.4 years if there were no cancer; 2.25 years would be added to the
average life expectancy for 35-year-olds. Also, of the nearly 2 million deaths that
