2005-1-17
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VOICE ONE:
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Sarah
Long.
VOICE TWO:
And I'm Bob Doughty. On our program this week: a progress report
on efforts to stop the disease polio and we answer a listener's
question about a common kind of cancer.
VOICE ONE:
But first, scientists are examining ways of improving their
ability to estimate the effects of underwater earthquakes. Today, we
look one system already in use.
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VOICE ONE:
Scientists did not expect the
powerful earthquake that caused huge, destructive waves in the
Indian Ocean last month. This is because technology for measuring
motion has never been placed on the floor of Indian Ocean.
Yet, experts have been watching for earthquakes in the Pacific
Ocean for more than fifty years. An international warning system was
established there in nineteen sixty-five. The system has its
headquarters in the American state of Hawaii.
Scientists there listen to sound waves directed at the ocean
floor for possible earthquakes and underwater motion. They also
watch water levels at more than one hundred water stations across
the Pacific Ocean. If destructive waves are discovered, warning
information is sent to more than one hundred places across the
Pacific. Experts believe that establishment of similar warning
systems in other areas could help to save many lives.
VOICE TWO:
Last month, an earthquake in the Indian Ocean caused a series of
events that killed more than one hundred sixty thousand people. The
earthquake struck in waters near the Indonesian island of Sumatra on
December twenty-sixth. The earthquake was one of the strongest
earthquakes ever measured. It had a rating of nine on the Richter
scale, the leading measure for earthquake strength.
The Indian Ocean earthquake
created huge shock waves, or tsunami. The tsunami struck Sumatra and
two groups of Indian islands in less than an hour. A short time
later, the deadly waves reached Sri Lanka and Thailand. Several
hours later, the waves reached coastal areas of eastern Africa.
Officials say this was enough time to warn countries of possible
danger.
VOICE ONE:
Scientists usually know within minutes after an underwater
earthquake if it was large enough to create tsunami waves. Yet,
warnings are worthless without a local civil defense system to
receive and act on them. Affected areas may lack the communications
systems needed to warn people quickly.
A tsunami warning system for South Asia is one subject to be
discussed this week at the World Conference on Disaster Reduction in
Kobe, Japan. Germany, Japan and the United States have each offered
to create a tsunami warning system in the Indian Ocean.
The Bush Administration will present a plan to deploy scientific
equipment throughout the Pacific, Indian and Atlantic Oceans and the
Caribbean Sea. The equipment would send messages from the ocean
floor to devices floating on top of the water. The information would
then be sent by satellite to scientists.
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VOICE TWO:
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| Child who has polio holds baby brother in arms (WHO photo) |
The World Health Organization says
the number of people infected with polio rose almost thirty percent
last year. W.H.O. officials say there were one thousand one hundred
seventy polio cases worldwide in two thousand four. That compares
with seven hundred eighty-four infections in two thousand three.
Ninety percent of the people infected last year live in three
countries -- Nigeria, India, and Pakistan. In fact, Nigeria had
sixty-five percent of all polio cases.
Anti-polio campaigns were halted in northern Nigeria after
Islamic leaders expressed concern about the safety of polio
vaccines. Vaccines help the body's natural defenses recognize and
fight disease.
VOICE ONE:
Polio is a disease that can make people unable to move their arms
or legs. It also can kill people. The virus spreads very quickly
among people who have not been given vaccines.
Recently, a polio vaccination campaign re-started in Nigeria.
However, there are already new cases of polio, both in and out of
the country. W.H.O. officials say the virus has spread to nearby
countries, including Benin, Chad, Ghana and Togo. W.H.O. officials
say conflicts in Ivory Coast and Sudan also affected efforts to stop
the disease.
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VOICE TWO:
The American performer Jerry Orbach died last month. He was
sixty-nine years old. The cause of death was prostate cancer. A
listener in Viet Nam wrote to ask us for information about prostate
cancer. Than Nguyen wants to know what causes the disease and how it
is treated.
Only males have prostate glands so only males get prostate
cancer. The gland is a part of the reproductive system. It is
involved in the production and storage of semen, the male
reproductive fluid. Semen is used to fertilize a female's egg.
A normal prostate is about the size of a small ball or walnut. A
cancer can make the prostate larger. This can cause pressure on the
bladder and restrict the release of liquid wastes. An enlarged
prostate can affect a man's ability to have sex. It also can cause
pain in the lower back, hips and upper part of the legs.
VOICE ONE:
The American Cancer Society estimates that about one in six men
in the United States will get prostate cancer. But, the group says
only one man in thirty-two will die from it. Prostate cancer is
common in older men.
The National Cancer Institute says more than seventy percent of
men with the disease are sixty-five years of age or older. However,
most prostate cancer grows slowly. So, many patients die of other
causes instead of the disease.
Scientists do not know the exact cause of prostate cancer. But
they have found things that can influence its development. The World
Health Organization says the foods a man eats may affect his chances
of developing the disease. Prostate cancer appears more common in
communities where animal fat, red meats, and high-fat milk products
are a major part of the diet.
VOICE TWO:
W-H-O officials say about two hundred fifty thousand people die
each year from prostate cancer. They say the death rate is about ten
times higher in Europe and North America than in Asia.
The Prostate Cancer Foundation says prostate cancer is the most
common cancer in the United States. The group also says it is the
second leading cause of cancer deaths among American men.
The American Cancer Society reports that prostate cancer is more
common among African-Americans than among white Americans. Also,
African Americans are two times as likely as whites to die from it.
The group says exercise might help reduce the risk of prostate
cancer. Also, men with fathers or brothers who have had the disease
are more likely to get it than those without such a family history.
VOICE ONE:
There are many things to consider when choosing a treatment for
prostate cancer. Some cancers grow so slowly they never cause any
major problems in a lifetime. In these cases, a man's doctor might
suggest simply watching for changes in the growth.
More rarely, a doctor may perform an operation to remove the
prostate. This is a complex surgery that can last as long as four
hours.
A third kind of treatment is radiation. High energy x-rays can be
used to kill cancer cells in the prostate. A doctor also may place
small radioactive seeds in the prostate to kill the cancer. Doctors
have greater control with this method so there is less risk of
damage to healthy tissue.
VOICE TWO:
Cancer that has spread beyond the prostate gland may require a
more aggressive treatment known as hormonal therapy. A doctor may
operate to remove the man's sex organs, or testicles. The testicles
are the main producer of male hormones called androgens. The doctor
may advise the patient to use drugs that can cut off the body's
androgen supply.
Doctors say one of the most important ways for men to reduce
their risk of death from prostate cancer is to find the disease
early. There are two ways to discover the disease before any signs
of it appear. A doctor will examine the prostate grand using his
fingers. He will feel for any hardness or growth.
A doctor also may test a man's blood to measure levels of a
protein called prostate-specific antigen. An injured or disease
prostate often expels P.S.A. The higher the P.S.A. level, the
greater the chance that the patient has prostate cancer.
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VOICE ONE:
This program was written by Karen Leggett, Jill Moss and Caty
Weaver. Cynthia Kirk was our producer. And, our engineer was Dwayne
Collins. I'm Sarah Long.
VOICE TWO:
And I'm Bob Doughty. Join us again next week for SCIENCE IN THE
NEWS in VOA Special English.
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