VOA标准英语2010年-Coal Burning Linked to Fluoride Diseas

A cluster of villages in China's Guizhou province has been plagued by an outbreak of disease that damages teeth and bones. Now, a new study by Chinese and American researchers puts the blame on polluted coal burned in home fireplaces.

 

In small quantities, fluoride can prevent tooth decay. But too much fluoride can lead to a whole spectrum² of symptoms, and that's what Chinese doctors were seeing, explains chemistry professor Joseph Gardella at the State University of New York at Buffalo³.

"It runs from everything as simple as blackened teeth to these very brittle⁴ bones, bone deformation⁵, so that leads to very debilitating⁶ disability," he said in a telephone interview. "And the rates of skeletal fluorosis in some of the villages are as high as 30 percent, although not all of those people who suffer are suffering the most extreme disability."

The most common source of fluoride disease is water pollution. But tests found no problem with the villages' water, so scientists started looking for another environmental source of fluoride.

Coal, which is burned for heating and cooking, was another suspect, but the coal itself wasn't polluted. However, advanced imaging techniques revealed that the culprit was another material burned with the coal.

"These are villagers that will collect what coal is available. And it turns out that they form briquettes, coal briquettes to burn, by mixing it with surface clay. And what we've learned is that the fluorine, as fluoride, is associated with this clay component," Gardella said.

The scientist says it's unclear exactly how the village residents were being poisoned by the fluoride. They might be breathing in the chemical, which is an ion of the element fluorine. Or it might be in tiny particles that settle on food.

"We were able to obtain dried peppers and dried corn samples from the villages and show that the particulate⁷ matter on the surfaces of these chili⁸ peppers was really high in fluorine content."

Either way, says University at Buffalo scientist Joseph Gardella, the Chinese government has launched a program to install chimneys to vent¹ the harmful fluoride out of villagers' homes.

Results of the research were presented in Albuquerque, New Mexico, at the International Symposium⁹ of the AVS, the scientific group formerly¹⁰ known as the American Vacuum Society.
 

1 vent   

n.通风口，排放口；开衩；vt.表达，发泄

参考例句：

• He gave vent to his anger by swearing loudly.他高声咒骂以发泄他的愤怒。
• When the vent became plugged,the engine would stop.当通风口被堵塞时，发动机就会停转。

2 spectrum   

n.谱，光谱，频谱；范围，幅度，系列

参考例句：

• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。

3 buffalo   

n.(北美)野牛；(亚洲)水牛

参考例句：

• Asian buffalo isn't as wild as that of America's. 亚洲水牛比美洲水牛温顺些。
• The boots are made of buffalo hide. 这双靴子是由水牛皮制成的。

4 brittle   

adj.易碎的；脆弱的；冷淡的；(声音)尖利的

参考例句：

• The pond was covered in a brittle layer of ice.池塘覆盖了一层易碎的冰。
• She gave a brittle laugh.她冷淡地笑了笑。

5 deformation   

n.形状损坏；变形；畸形

参考例句：

• The deformation frequencies are not sufficiently distinctive.其变形频率不是十分明显的。
• The calculated deformation is almost equal to the real situation by measurement.经检测，计算变形量与实际情况基本一致。

6 debilitating   

a.使衰弱的

参考例句：

• The debilitating disease made him too weak to work. 这个令他衰弱的病，使他弱到没有办法工作。
• You may soon leave one debilitating condition or relationship forever. 你即将永远地和这段霉运说拜拜了。

7 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。

8 chili   

n.辣椒

参考例句：

• He helped himself to another two small spoonfuls of chili oil.他自己下手又加了两小勺辣椒油。
• It has chocolate,chili,and other spices.有巧克力粉，辣椒，和其他的调味品。

9 symposium   

n.讨论会，专题报告会；专题论文集

参考例句：

• What have you learned from the symposium?你参加了这次科学讨论会有什么体会？
• The specialists and scholars present at the symposium come from all corners of the country.出席研讨会的专家学者们来自全国各地。

10 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。