Name: 【TED-Ed】霧霾科學 (The science of smog - Kim Preshoff)
Uploaded: 2018-02-16T21:59:59.000Z
Duration: 5 min 44 s
Description: On July 26, 1943, Los Angeles was blanketed by a thick gas that stung people’s eyes and blocked out the Sun. Panicked residents believed their city had been attacked...

關係子句

Los Angeles was blanketed by a thick gas that stung people's eyes

洛杉磯被一層濃厚、使人眼睛感到刺痛

Panicked residents believed their city had been attacked using chemical warfare.

驚恐的居民相信他們的城市被化學武器攻擊了

the word smog was coined at the beginning of the 20th century

霧霾這個詞是在20世紀初被創造出來的

to describe the thick gray haze that covered cities

when smoke from coal-burning home stoves and factories

But the smog behind the LA panic was different.

是微黃色的，且混雜著化學臭味

Since the city didn't burn much coal, its cause would remain a mystery

但這個城市並沒有燒很多煤，它的成因一直是個謎

until a chemist named Arie Haagen-Smit identified two culprits,

直到一位名叫 Arie Haagen-Smit 的化學家發現了兩個兇手

揮發性的有機化合物，或稱 VOCs，

VOCs are compounds that easily become vapors

and may contain elements, such as carbon,

可能包含其他物質的混合物，像是碳、

Some are naturally produced by plants and animals,

Meanwhile, the incomplete combustion of gas in motor vehicles

That's what gives this type of smog its yellowish color.

VOCs and nitrogen oxide react with sunlight

VOCs 和一氧化二氮對陽光起反應

to produce secondary pollutants called PANs and tropospheric,

並製造出第二種污染物，稱作 PANs 和位於對流層

PANs and ozone cause eye irritation and damage lung tissue.

PANs 和臭氧會刺激眼睛，並造成肺部的傷害

Both are key ingredients in photochemical smog,

這些都是光化學霧霾的主要成分

So why does smog affect some cities but not others?

那為何霾害只出現在幾個城市呢？

Both industrial and photochemical smog combine manmade pollution

當地天氣及地理環境的人造污染

London's high humidity made it a prime location for industrial smog.

高濕度讓倫敦成了累積工業霧霾的地方

Photochemical smog is strongest in urban areas with calm winds

乾燥、溫暖、晴天的都會地區最為嚴重

The ultraviolet radiation from sunlight provides the energy necessary

太陽的紫外射線提供了必需的能量

to breakdown molecules that contribute to smog formation.

像是洛杉磯這種山地環繞的城市

或像是北京這種坐落在盆地的城市

are also especially vulnerable to smog since there's nowhere for it to dissipate.

也都特別容易受霾害，因為沒有地方可以讓霧霾消散

That's also partially due to a phenomenon known as temperature inversion,

其中一部分原因，是所謂的逆溫現象所造成的

where instead of warm air continuously rising upward,

a pollution-filled layer of air remains trapped near the Earth's surface

被汙染的空氣層被囚禁在地球表面

被一層輕薄的暖空氣覆蓋在上面

exacerbate conditions like asthma and emphysema,

and increase the risk of respiratory infections like bronchitis.

並增加肺部感染的危險，像是支氣管炎

Smog can be especially harmful to young children and older people

霧霾對小孩及老人會有特別大的傷害，

and exposure in pregnant women has been linked to low birth weight

孕婦暴露在霾害中會使肚子裡的寶寶體重減輕

Secondary pollutants found in photochemical smog

光化學霧霾中的第二種汙染物質

can damage and weaken crops and decrease yield,

Yet for decades, smog was seen as the inevitable price of civilization.

到目前幾十年，霾害看來是文明無法避免付出的代價

Londoners had become accustomed to the notorious pea soup fog

倫敦人已經習慣了惡名昭彰的霧霾

when the Great Smog of London shut down all transportation in the city for days

直到1962年倫敦煙霧事件，迫使所有交通工具停止

and caused more  than 4,000 respiratory deaths.

並造成超過4000人因呼吸疾病死亡

banned burning coal in certain areas of the city,

Similarly, regulations on vehicle emissions and gas content in the US

美國也對交通工具的排氣量頒布了類似的法案

reduced the volatile compounds in the air and smog levels along with them.

減少空氣中的揮發化合物及霧霾的汙染程度

Smog remains a major problem around the world.

霧霾在世界上是個很大的問題，

Countries like China and Poland that depend on coal for energy

像是中國、波蘭這些仰賴煤炭作為能源的國家

experience high levels of industrial smog.

Photochemical smog and airborne particles from vehicle emissions

交通工具產生的光化學霾害和懸浮粒子

Governments have tried many methods to tackle it,

許多政府已經嘗試了許多解決方法

such as banning cars from driving for days at a time.

像是規定一天車輛行駛的特定時間

As more than half of the world's population crowds into cities,

當超過世界一半的人口擠進城市

considering a shift to mass transit and away from fossil fuels

就要思考如何排除大量化石燃料汙染

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【TED-Ed】霧霾科學 (The science of smog - Kim Preshoff)

vulnerable

inevitable

susceptible

panic