SCIENCE IN THE NEWS

（单词翻译）

SCIENCE IN THE NEWS - September 10, 2002: South Asia's Pollution / El Nino in the Pacific / Anthrax-
Eating Enzyme¹

VOICE ONE:

This is Sarah Long.

VOICE TWO:

And this is Bob Doughty² with Science in the News, a VOA Special English program about recent developments
in science. Today, we tell about an enzyme that can destroy the deadly anthrax bacterium³. We tell about the
effects of a weaker weather condition called El Nino. And we tell about a cloud of pollution covering much of
southern Asia.

((THEME))

VOICE ONE:

American scientists say they have developed an enzyme that can destroy the deadly anthrax bacterium. The
scientists say the enzyme could effectively treat people infected with the bacterium, including drug-resistant
forms of the disease. They say the enzyme also could be used to immediately identify areas thought to contain
anthrax particles.

Scientists with the Rockefeller University in New York Cuty developed the anthrax-
killing protein. They described their work in the British publication Nature.

VOICE TWO:

Anthrax is a severe infectious⁴ disease that mainly attacks animals. However, anthrax
also can infect humans. Usually, people get the disease by touching⁵ infected animals
or animal products.

Anthrax
However, anthrax particles were blamed for five deaths in the United States last
year after the September eleventh terrorist⁶ attacks. Many other people became sick. The particles were found on
letters sent to political leaders and members of the media. The discovery of the letters containing anthrax
temporarily slowed mail service in the United States. No suspects have yet been charged in the investigation⁷.

VOICE ONE:

The United States Defense⁸ Department provided money for the new research on anthrax. The Rockefeller
University scientists developed the anthrax-killing enzyme by using a virus that attacks bacteria. Viruses can
infect both humans and bacteria. Viruses that infect bacteria are called bacteriophages or “bacteria-eating
viruses.” They are also known as phage (fayj).

Phage are the most common life form on Earth. They can be found in soil, water or anywhere else that bacteria
live. Phage have been battling anthrax and other kinds of bacteria for millions of years. Like viruses that infect
humans, phage inject their genetic⁹ material into the bacterial¹⁰ cell. Then, the virus reproduces¹¹ and bursts out
before attacking the next cell.

VOICE TWO:

The Rockefeller University scientists worked with phage that infect the anthrax bacterium. They identified the
enzyme that allows the phage to burst out and escape from the anthrax bacterium. The scientists showed that just
a small amount of the enzyme can quickly destroy a laboratory container filled with anthrax.

The scientists say this enzyme will attack only anthrax because it was developed from a phage that only infects


the anthrax bacterium.

The scientists tested the enzyme on mice infected with a disease similar to anthrax. All of the mice usually die
within four hours of being infected with this disease. The scientists injected the new enzyme into the mice fifteen
minutes after they were infected with the disease. As many as eighty percent of the injected animals survived.

VOICE ONE:

Vincent Fischetti of the Rockefeller University helped organize the study. He believes that the anthrax-killing
enzyme would work as well in humans, with almost no bad effects. He also thinks the bacterium used in the
anthrax attacks last year will not develop a resistance to the new treatment. That is because the enzyme is its
natural enemy.

The scientists also described how the enzyme can be used to confirm the presence of anthrax particles in places
like buildings. They say the test for anthrax can be done in as few as ten or fifteen minutes. Some current tests
require several days to identify the presence of anthrax. The new tests are done with a hand-held light meter. The
device shows glowing particles if anthrax is present.

((MUSIC BRIDGE))

VOICE TWO:

The El Nino weather condition has returned. However, officials at the United States National Weather Service
say El Nino is weaker than usual this year. El Nino is a change in the atmosphere over the Pacific Ocean. It
happens every four to five years.

El Nino is Spanish for “the little one” or “the Christ child.” The weather
condition is called El Nino because its effects increase in December, at about
Christmas time.

Normally, water temperatures in the western Pacific Ocean increase near the end of
the year. This causes more rainfall in Indonesia, Australia and other nearby places.
At the same time, cold ocean water causes less rainfall in the eastern Pacific Ocean,
near South America. The opposite happens during El Nino. Pacific Ocean
temperatures increase near South America, causing unusually high amounts of
rainfall there. And, El Nino causes dry weather in Indonesia and Australia.

VOICE ONE:

A strong El Nino can severely¹² affect the weather all over the world. The last powerful El Nino was in nineteen-
ninety-seven and nineteen-ninety-eight. It caused major floods around the world. El Nino also led to extremely
dry weather in some areas. Reports say the weather condition caused the deaths of about twenty-four-thousand
people.

So experts say having a weaker El Nino this year is good news. Weather scientists say rainfall has been higher
than usual in South America. The experts say the effects of El Nino will begin in November in the United States.
Drier weather is expected in the northwestern states. The northern states may have a warmer winter. But,
scientists say El Nino will not be strong enough to prevent this year’s powerful storms in the Atlantic Ocean.

((MUSIC BRIDGE))

VOICE TWO:

A United Nations study says a thick cloud of pollution covering southern Asia threatens the lives of millions of
people. Scientists say the pollution could increase lung diseases and cause early deaths. The cloud is also
damaging agriculture and affecting rainfall levels. Scientists are calling it the Asian Brown Cloud. It has affected¹³
Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. The pollution cloud is three
kilometers high. Scientists say it can move halfway¹⁴ around the world in a week.

VOICE ONE:

An earlier El Nino (white
area)
(Photo -NOAA)

The cloud is a mixture of ash, acids, aerosols¹⁵ and other particles. It is the result of forest fires, the burning of
agricultural waste, and huge increases in the burning of fuels by vehicles, industries and power stations.

Pollution from millions of bad cooking stoves has made the problem worse. Many poor people burn fuels like
wood and animal waste in such stoves.

Scientists say the cloud of pollution appears to cool the land and oceans by blocking sunlight. They say it reduces
the amount of sunlight reaching the Earth’s surface by as much as fifteen percent. At the same time, heat inside
the cloud warms the lower parts of the atmosphere.

VOICE TWO:

Scientists say this combination could be changing winter rainfall levels in Asia. They say rainfall has increased
over the eastern coast of Asia. But it has dropped sharply¹⁶ over parts of northwestern Asia. The report says the
cloud could reduce rainfall over northwestern Pakistan, Afghanistan and western China by up to forty percent.

Harmful chemicals from the cloud are mixing with rainfall. This acid rain damages crops and trees and threatens
public health. Scientists are concerned that the pollution will intensify¹⁷ during the next thirty years as the
population of Asia increases to an estimated five-thousand-million people.

Scientists say the Asian Brown Cloud could affect other parts of the world unless steps are taken to reduce
pollution. Environmental groups say action is needed to find clean, renewable energy sources.

More than two-hundred scientists took part in the U-N study. The U-N Environment Program prepared the study
for the World Summit¹⁸ on Sustainable Development. That meeting took place in Johannesburg, South Africa. It
ended last week.

((THEME))

VOICE ONE:

This SCIENCE IN THE NEWS program was written by George Grow, Doreen Baingana and Cynthia Kirk. It
was produced by Cynthia Kirk. This is Sarah Long.

VOICE TWO:

And this is Bob Doughty. Join us again next week for more news about science in Special English on the Voice
of America.

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