VOA慢速英语2009年-SCIENCE IN THE NEWS - What You Can Do To P

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Faith Lapidus. Summer is a busy time for travel. Today, we discuss ideas about how to stay healthy on a long trip.

VOICE ONE:

For years, people have wondered whether they are safe from germs when they travel in small, enclosed areas. They worry about close contact with others who may be sick.

The current spread of a swine influenza² virus has added to these concerns. Recently, the World Health Organization raised its warning about the new H1N1 virus to its highest level. W.H.O. Director-General Margaret Chan declared the sickness a pandemic – a disease that has spread to many nations. Given this information, many people want to know how safe is it to travel?

VOICE TWO:

The answers people are getting may seem conflicting. For example, a W.H.O. statement urged nations not to close their borders or limit trade and travel. Director-General Chan said cases are generally mild for most people. Still, W.H.O. officials continue to report new cases across the world.

In the past, the W.H.O. and experts with America's Centers for Disease Control and Prevention noted³ guidance for disease spread on airplanes. The experts said you could get infected only if you sit within two rows of someone who is sick. That would be a distance of up to three meters from the sick person. And this was true only if you sat there for more than eight hours.

VOICE ONE:

But a travel-health expert says this guidance may not be helpful for swine flu. Mark Gendreau works at the Lahey Clinic Medical Center in the American state of Massachusetts. He suggests steps that could help prevent getting swine flu on an airplane.

His advice includes keeping the airflow over your seat on the "low" position. The doctor says you should point the device so the flow of air is just in front of your face.

Infection can spread through touching⁴ an infected surface and then touching your eyes, nose or mouth. Doctor Gendreau suggests cleaning your hands with soap and water, or using hand-sanitizer wipes. These products should contain at least fifty percent alcohol. In addition, he said you may want to cover your face with a mask. Most importantly, avoid traveling when you are sick.

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VOICE TWO:

Clearly, most people do not get sick while taking long trips. But something else might interfere⁵ with your travel plans. You could be placed in medical isolation⁶ if someone you traveled with on a plane is suspected of having swine flu.

The top official of an American city recently had this experience. New Orleans Mayor Ray Nagin, his wife and a security guard spent several days in a hospital-like center in Shanghai, China. At the time, they were on their way to Australia. Mayor Nagin was preparing to speak there. But they were detained because of someone who sat near them on their arriving flight. The person was suspected of having swine flu. The Nagins did not get sick.

VOICE ONE:
　
Workers in protective clothing prepare a meal for a quarantined person in Lingang, China

Students from a high school in Maryland had a similar experience. On a recent visit to China, the students had to spend several days in hotel rooms in the city of Kaili. They were barred from leaving their rooms because someone on their flight was suspected of having the flu. Tests later proved that the suspicion was wrong.

The students lost several days of sight-seeing. But one girl said she was still glad she made the trip.

Many other people share her feeling. One man from Maryland says he has planned a trip to Ireland for many years. He wants to visit the burial places of his grandparents. He says it will take more than a pandemic to keep him from making his trip.

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VOICE TWO:

Technology on most airplanes might make you feel safer about air travel. The United States Federal Aviation Administration says most large passenger planes now use HEPA filters. The devices are designed to remove dangerous particles from the air.

The letters H-E-P-A represent the words High Efficiency Particulate⁸ Air. HEPA filters capture almost all particles in the air that are zero point three microns in size or larger.

America's Atomic Energy Commission developed HEPA filters many years ago. The goal was to protect workers who were developing the atomic bomb. The first HEPA filters removed radioactive particles from the air. Today, the filters clean the air in planes.

VOICE ONE:

The Centers for Disease Control says HEPA filters are effective in clearing the air of many particles that cause disease. Makers⁹ of the devices say they kill bacteria and viruses because they help to remove the wetness that germs need to survive. But HEPA filters cannot remove disease-causing particles smaller than zero point three microns. These will continue to move around in the air and can infect people.

On a passenger cruise ship, fresh air is available on decks and in other places above sea level. A spokesperson for the Cruise Lines International Association says other air quality depends on the requirements of the nation where a ship was built.

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VOICE TWO:

Experts say people should know about other health concerns that can strike when traveling by air. One of these is hypoxia. It results from a lack of oxygen to the brain. Experts say the body begins losing oxygen minutes after an airplane leaves the ground.

The air pressure in a plane during flight is lower than at sea level. This makes it more difficult for the body to effectively use the same amount of oxygen as it would on the ground. Fewer oxygen molecules¹⁰ cross the tissues in the lungs and reach the bloodstream.

The result is a five to twenty percent drop in the amount of oxygen in the blood. This reduces the amount of oxygen that reaches the organs of the body.

VOICE ONE:

One effect of this lack of oxygen to the brain is a headache. When this happens, the heart attempts to fix the situation by beating harder and faster. This can make the traveler feel tired.

These signs of hypoxia are not dangerous in a healthy person. But a drop in oxygen levels can cause a health emergency in people with heart or lung problems. They might lose consciousness or even suffer a heart attack.

Experts say use of cigarettes and alcoholic¹¹ liquids also reduces the body's ability to use oxygen. So they suggest that people not drink alcohol or smoke cigarettes either before or during a flight. They also say persons with heart or lung problems should seek advice from their doctor before flying.

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VOICE TWO:

Another problem for travelers can be a condition called deep vein¹² thrombosis. A thrombosis is a blood clot⁷ -- a condition in which some blood thickens and blocks the flow to the heart. Blood clots¹³ can kill if they move to the heart and lungs and stop needed oxygen from reaching those important organs. This is known as a pulmonary embolism.

The World Health Organization says passengers who sit still for four or more hours face a greater risk of developing blood clots. But it says only one in six thousand people develop deep vein thrombosis.

VOICE ONE:

Last week, Harvard University researchers reported that people who travel are three times more likely than others to develop deep vein thrombosis. The researchers examined information from fourteen earlier studies. They found the longer the trip, the greater the threat of deep vein thrombosis. They even found a measurable increase in the condition for every two hours sitting in a car.

Experts say the chance of a clot also increases if a person does not drink enough water. They say passengers who sit for hours need to drink plenty of water -- not liquids that contain alcohol or caffeine. Passengers should also increase blood flow to the legs. The doctors suggest covering your legs with support stockings and walking every hour or so during the trip. Or, at least move your legs and feet.

VOICE TWO:

Doctors say anyone with pain, swelling¹⁴ or red skin on a leg during or after a long trip may have a blood clot. Anyone with such signs should see a doctor as soon as possible. The condition many times can be treated with drugs that thin the blood and stop the clot from moving through the body.

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VOICE ONE:

This SCIENCE IN THE NEWS was written by Nancy Steinbach and Jerilyn Watson. Our producer was Brianna Blake. I'm Bob Doughty.

VOICE TWO:

And I'm Faith Lapidus. Read and listen to our programs at voaspecialenglish.com. Join us again next week for more news about science in Special English on the Voice of America.

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

3 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

4 touching   

adj.动人的，使人感伤的

参考例句：

• It was a touching sight.这是一幅动人的景象。
• His letter was touching.他的信很感人。

5 interfere   

v.(in)干涉，干预；(with)妨碍，打扰

参考例句：

• If we interfere, it may do more harm than good.如果我们干预的话，可能弊多利少。
• When others interfere in the affair,it always makes troubles. 别人一卷入这一事件，棘手的事情就来了。

6 isolation   

n.隔离，孤立，分解，分离

参考例句：

• The millionaire lived in complete isolation from the outside world.这位富翁过着与世隔绝的生活。
• He retired and lived in relative isolation.他退休后，生活比较孤寂。

7 clot   

n.凝块；v.使凝成块

参考例句：

• Platelets are one of the components required to make blood clot.血小板是血液凝固的必须成分之一。
• The patient's blood refused to clot.病人的血液无法凝结。

8 particulate   

adj.微小的；n.微粒，粒子

参考例句：

• A special group was organized to dig up the particulate of the case.成立了一个专门小组来查明该案件的各个细节。
• Lungs retain relatively insoluble particulate material.肺脏内留有不溶解的颗粒物质。

9 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

10 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

11 alcoholic   

adj.（含）酒精的，由酒精引起的；n.酗酒者

参考例句：

• The alcoholic strength of brandy far exceeds that of wine.白兰地的酒精浓度远远超过葡萄酒。
• Alcoholic drinks act as a poison to a child.酒精饮料对小孩犹如毒药。

12 vein   

n.血管，静脉；叶脉，纹理；情绪；vt.使成脉络

参考例句：

• The girl is not in the vein for singing today.那女孩今天没有心情唱歌。
• The doctor injects glucose into the patient's vein.医生把葡萄糖注射入病人的静脉。

13 clots   

n.凝块( clot的名词复数 )；血块；蠢人；傻瓜v.凝固( clot的第三人称单数 )

参考例句：

• When you cut yourself, blood clots and forms a scab. 你割破了，血会凝固、结痂。 来自《简明英汉词典》
• Milk clots when it turns sour. 奶变酸就凝块。 来自《现代英汉综合大词典》

14 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。