Geography Reference
In-Depth Information
TABLE 2.1
Leading Causes of Death in the United States, 2010.
Data
from
: Center for Disease Control, National Center for Health
Statistics, 2010 and U.S. Census Statistical Abstract 2011.
the result can be serious metabolic malfunction. For
example, some people suffer from a malady called primary
lactose intolerance. If you suffer from this disorder, you
do not have an adequate supply of one (or a set) of enzymes
that you need to break down the milk sugar lactose.
Cause
Percent
1. Heart Disease
25%
2. Cancer
23%
AIDS
Low life expectancies in some parts of the world are
caused by the ravages of diseases such as
AIDS
(Acquired
Immune Defi ciency Syndrome)—a disease identifi ed in
Africa in the early 1980s. Undoubtedly, AIDS had taken
hold in Africa years earlier, perhaps decades earlier. But
its rapid diffusion worldwide began in the 1980s, creat-
ing one of the greatest health catastrophes of the past
century. Nowhere has its impact been greater than in
Africa itself.
Medical geographers estimate that in 1980 about
200,000 people were infected with HIV (Human Immu-
nodefi ciency Virus, which causes AIDS), all of them
Africans. By 2007, the number worldwide exceeded 33.2
million according to the United Nations AIDS Program,
with 68 percent (22.5 million) of all cases in Subsaharan
Africa! The infection rate has been slowing, and some
regions have experienced a downturn, but eastern
Europe and Central Asia have recently seen a surge in
HIV infection.
AIDS is a debilitating disease that weakens the body
and reduces its capacity to combat other infections. It is
spread through bodily contact that involves the exchange
of bodily fl uids such as blood or semen. Sexual activity and
shared needles can transmit it, but so can blood transfu-
sions. Over a period of years, a person's immune system is
impaired, weight loss and weakness set in, and other affl ic-
tions, such as cancer or pneumonia, may hasten an
infected person's demise.
Over the past two decades, the AIDS pandemic has
reached virtually all parts of the world, but its full dimen-
sions are unknown. People infected by HIV do not imme-
diately display visible symptoms of the disease; they can
carry the virus for years without being aware of it, and
during that period they can unwittingly transmit it to oth-
ers. In its earliest stages a blood test is needed to confi rm
HIV's presence, but millions go untested. Add to this the
social stigma many people attach to this malady, and it is
evident that offi cial statistics on AIDS lag behind the real
numbers.
That is true not only in Africa but in other parts of
the world as well; both India and China, for example,
long denied that AIDS presents a serious health threat to
their populations. Now China is reporting at least
650,000 infected, and the number in India may well
exceed 5 million. Estimates of the number of cases in the
United States surpass 1 million; in Middle and South
3. Stroke
6%
4. Chronic Lower Respiratory Disease
5%
5. Accidents
5%
6. Diabetes
3%
7. Alzheimer's Disease
3%
pneumonia, diarrheal diseases, and heart diseases (in that
order) were the chief killers. Today, heart disease and
cancer head the list, with stroke (cerebral hemorrhage)
next and accidents also high on the list (Table 2.1). In the
early 1900s, tuberculosis and pneumonia caused 20 per-
cent of all deaths; today, they cause fewer than 5 percent.
The diarrheal diseases, which were so high on the old list,
are now primarily children's maladies. Today, the diar-
rheal diseases are not even on the list of the 10 leading
causes of death.
At the global scale, diseases of infancy have been
largely defeated, and such infectious diseases as tuberculosis
and pneumonia are less serious threats than they were. The
battles against cancer and heart disease, however, are far
from won. Recent decades have brought new lifestyles, new
pressures, new consumption patterns, and exposure to new
chemicals, and we do not know how these affect our health.
In order to distribute adequate food supplies to populations
in huge urban areas, we add various kinds of preservatives to
foods without knowing exactly how they will affect our
health in the long run. We substitute artifi cial fl avoring for
sugar and other calorie-rich substances, but some of those
substitutes have been proven to be dangerous. Despite all
the sugar substitutes, obesity plagues a signifi cant percent-
age of the U.S. population, bringing with it heart disease
and diabetes. Even the treatment of drinking water with
chemicals is rather recent in the scheme of global popula-
tion change, and we do not know its long-term effects.
Future chronic diseases may come from practices we take
for granted as normal now.
Genetic diseases are of particular interest to medical
geographers because they are disorders that tend to be
transferred from one generation to the next and display
clustering that raises questions about environment and
long-term adaptation. Prominent among these are meta-
bolic diseases—the body's inability to process all elements
of the diet—in which enzymes play a key role. If the body
fails to produce enough (or any) of a particular enzyme,
