我们一直都知道吸烟的危害，但香烟究竟如何伤害我们?

Cigarettes aren’t good for us.

香烟对我们不好。

That’s hardly news--we’ve known about the dangers of smoking for decades.

那不是新闻了。数十年前我们就已经知道抽烟的危险性。

But how exactly do cigarettes harm us?

但香烟到底如何伤害我们?

Let’s look at what happens as their ingredients

咱们来看看，香烟的成份通过

make their way through our bodies,

我们的身体时会发生什么状况，

and how we benefit physically when we finally give up smoking.

以及当我们终于戒烟时身体能得到什么好处。

With each inhalation,

每一次吸入，

smoke brings its more than 5,000 chemical substances

烟就会把它本身超过五千种化学物质带入体内，

into contact with the body’s tissues.

和身体的组织接触。

From the start, tar, a black, resinous material,

从一开始，焦油，一种黑色树脂原料，

begins to coat the teeth and gums,

会开始覆盖牙齿和牙床，

damaging tooth enamel, and eventually causing decay.

损害牙齿珐琅质，最终造成蛀牙。

Over time, smoke also damages nerve-endings in the nose,

随时间过去，烟也会伤害鼻子中的神经末梢，

causing loss of smell.

造成嗅觉失灵。

Inside the airways and lungs,

在气道和肺中，

smoke increases the likelihood of infections,

烟会增加感染的可能性，

as well as chronic diseases like bronchitis and emphysema.

以及慢性病的可能性，如支气管炎和肺气肿。

It does this by damaging the cilia,

原因是因为它会伤害纤毛，

tiny hairlike structures whose job it is to keep the airways clean.

纤毛是像毛一样的构造，功能是保持气道干净。

It then fills the alveoli,

烟接着会充满肺泡，

tiny air sacs that enable the exchange of oxygen and carbon dioxide

肺泡是小小的气囊，让肺部和血液能够进行

between the lungs and blood.

氧气和二氧化碳的交换，

A toxic gas called carbon monoxide crosses that membrane into the blood,

一氧化碳是一种有毒气体，它会穿过那薄膜，进入血液，

binding to hemoglobin

和血红素结合，

and displacing the oxygen it would usually have transported around the body.

取代血红素原本要在身体中运输的氧气。

That’s one of the reasons smoking can lead to oxygen deprivation

这就是抽烟会导致供氧不足以及呼吸短促

and shortness of breath.

背后的原因之一。

Within about 10 seconds,

大约只要十秒，

the bloodstream carries a stimulant called nicotine to the brain,

血液流动就会把一种叫做尼古丁的兴奋剂带到大脑，

triggering the release of dopamine and other neurotransmitters

触发多巴胺及其他神经递质的释放，

including endorphins

包括脑内啡，

that create the pleasurable sensations which make smoking highly addictive.

它能创造出快乐的感觉，因此抽烟非常容易上瘾。

Nicotine and other chemicals from the cigarette

尼古丁和来自香烟的其他化学物质

simultaneously cause constriction of blood vessels

会同时造成血管紧缩，

and damage their delicate endothelial lining,

并伤害它们精细的内膜面，

restricting blood flow.

因而限制血流。

These vascular effects lead to thickening of blood vessel walls

这些对血管的影响会导致血管管壁变厚，

and enhance blood platelet stickiness,

增加血小板的黏度，

increasing the likelihood that clots will form

因此更有可能会有血块生成，

and trigger heart attacks and strokes.

触发心脏病或中风。

Many of the chemicals inside cigarettes can trigger dangerous mutations

香烟中有许多化学物质会触发人体 DNA

in the body’s DNA that make cancers form.

产生危险的病变，形成癌症。

Additionally, ingredients like arsenic and nickel

此外，像砷和镍这些成份

may disrupt the process of DNA repair,

可能会打断 DNA 修复的过程，

thus compromising the body’s ability to fight many cancers.

因而危害到身体对抗癌症的能力。

In fact, about one of every three cancer deaths in the United States

事实上，在美国，每三件因癌症过世的案例中

is caused by smoking.

就有一件是由抽烟造成的。

And it’s not just lung cancer.

且不只是肺癌。

Smoking can cause cancer in multiple tissues and organs,

抽烟会造成数个组织和器官的癌症，

as well as damaged eyesight

还会伤害视力，

and weakened bones.

弱化骨头。

It makes it harder for women to get pregnant.

女性会更难怀孕。

And in men,it can cause erectile dysfunction.

男性则可能会因为抽烟而引起勃起功能障碍。

But for those who quit smoking,

但对于戒烟的人来说，

there’s a huge positive upside

有非常正面的一面，

with almost immediate and long-lasting physical benefits.

几乎可说马上就能得到持续很久的身体益处。

Just 20 minutes after a smoker’s final cigarette,

抽烟者抽完最后一根香烟之后二十分钟，

their heart rate and blood pressure begin to return to normal.

他们的心跳和血压就会开始回到正常。

After 12 hours, carbon monoxide levels stabilize,

十二小时后，一氧化碳的量就会稳定下来，

increasing the blood’s oxygen-carrying capacity.

血液运载氧的能力又会增加。

A day after ceasing,

戒烟一天后，

heart attack risk begins to decrease as blood pressure and heart rates normalize.

随着心跳和血压变正常，心脏病的风险也会开始下降。

After two days,

两天后，

the nerve endings responsible for smell and taste start to recover.

负责嗅觉和味觉的神经末稍会开始恢复。

Lungs become healthier after about one month,

大约一个月后，肺会变得更健康，

with less coughing and shortness of breath.

比较少发生咳嗽和呼吸短促。

The delicate hair-like cilia in the airways and lungs

气道和肺部的脆弱纤毛

start recovering within weeks,

会在数周内开始恢复，

and are restored after 9 months, improving resistance to infection.

九个月后会复元，改善对感染的抵抗力。

By the one-year anniversary of quitting,

戒烟周年庆的时候，

heart disease risk plummets to half as blood vessel function improves.

随着血管功能改善，心脏疾病风险只剩一半。

Five years in,

五年时，

the chance of a clot forming dramatically declines,

形成血块的机会会明显下降，

and the risk of stroke continues to reduce.

中风的风险持续减少。

After ten years, the chances of developing fatal lung cancer

十年后，发展致命肺癌的机会

go down by 50%,

会下降 50%，

probably because the body’s ability to repair DNA is once again restored.

可能是因为身体修复DNA 的能力再次复元了。

Fifteen years in, the likelihood of developing coronary heart disease

十五年后，发展出冠状动脉疾病的可能性

is essentially the same as that of a non-smoker.

基本上会和不抽烟的人一样。

There’s no point pretending this is all easy to achieve.

没必要假装这是很容易达成的。

Quitting can lead to anxiety and depression,

戒烟会导致焦虑和忧郁，

resulting from nicotine withdrawal.

造成尼古丁戒断。

But fortunately, such effects are usually temporary.

但，幸运的是这些影响通常是暂时的。

And quitting is getting easier, thanks to a growing arsenal of tools.

现在也有越来越多工具让戒烟变得更容易。

Nicotine replacement therapy through gum,

尼古丁取代疗法用口香糖、

skin patches,

皮肤贴片、

lozenges,and sprays

锭剂，还有喷剂，

may help wean smokers off cigarettes.

都可能协助抽烟者戒烟。

They work by stimulating nicotine receptors in the brain

这些工具的作用是刺激大脑中的尼古丁接收器，

and thus preventing withdrawal symptoms,

因而避免戒断症状发生，

without the addition of other harmful chemicals.

且不需要用到其他有害的化学物质。

Counselling and support groups,

谘询和支持小组、

cognitive behavioral therapy,

认知行为疗法，

and moderate intensity exercise

以及适当强度的运动，

also help smokers stay cigarette-free.

也能协助抽烟者不去碰香烟。

That’s good news,

那是好消息，

since quitting puts you and your body on the path back to health.

因为戒烟能让你和你的身体越来越健康。