Cigarettes aren't good for us.
香烟对我们无益。
That's hardly news - we've known about the dangers of smoking for decades.
这已经不算是新闻了——几十年来我们一直都知道抽烟的危害。
But how exactly do cigarettes harm us?
但是香烟到底是怎么伤害我们的？
Let's look at what happens as their ingredients make their way through our bodies, and how we benefit physically when we finally give up smoking.
让我们看看，当香烟的成分进入我们的身体时，会发生什么，以及戒烟后对身体有什么好处。
With each inhalation, smoke brings its more than 5,000 chemical substances into contact with the body's tissues.
每吸一次烟，烟雾会携带五千种以上的化学成分，和身体组织接触。
From the start, tar, a black, resinous material, begins to coat the teeth and gums, damaging tooth enamel, and eventually causing decay.
从一开始，焦油，一种黑色的树枝材料，会覆盖牙齿和牙龈，损伤牙釉质，最终导致腐烂。
Over time, smoke also damages nerve-endings in the nose, causing loss of smell.
随着时间的推移， 烟雾也会伤害鼻子中的神经末梢，导致嗅觉丢失。
Inside the airways and lungs, smoke increases the likelihood of infections, as well as chronic diseases like bronchitis and emphysema.
在气道和肺内部，抽烟会增加感染的可能性，以及慢性疾病，比如支气管炎和肺气肿。
It does this by damaging the cilia, tiny hairlike structures whose job it is to keep the airways clean.
它是通过破坏纤毛来实现的，微小的毛发状结构，其作用是保持气道清洁。
It then fills the alveoli, tiny air sacs that enable the exchange of oxygen and carbon dioxide between the lungs and blood.
然后填充肺泡，微小的空气囊能使氧气和二氧化碳在肺部和血液之间交换。
A toxic gas called carbon monoxide crosses that membrane into the blood, binding to hemoglobin and displacing the oxygen it would usually have transported around the body.
一个叫一氧化碳的毒气穿过膜进入血液，使血红蛋白结合，以及置换氧气，它通常会在身体周围传播。
That's one of the reasons smoking can lead to oxygen deprivation and shortness of breath.
这就是吸烟可导致缺氧和呼吸急促的原因之一。
Within about 10 seconds, the bloodstream carries a stimulant called nicotine to the brain, triggering the release of dopamine and other neurotransmitters including endorphins that create the pleasurable sensations which make smoking highly addictive.
在大概十秒的范围内，血液携带一种叫做尼古丁的兴奋剂进入大脑，多巴胺和其他神经递质释放的触发，包括内啡肽，会通过制造愉快的感觉，使吸烟上瘾。
Nicotine and other chemicals from the cigarette simultaneously cause constriction of blood vessels and damage their delicate endothelial lining, restricting blood flow.
香烟携带的尼古丁和其他化学成分，会使血脉缢缩，同时损伤它们脆弱的内皮细胞，限制血流。
These vascular effects lead to thickening of blood vessel walls and enhance blood platelet stickiness, increasing the likelihood that clots will form and trigger heart attacks and strokes.
这些血管效应会导致血脉壁增厚和提高血小板的黏度，提高血块形成的可能性，引发心脏病发作和中风。
Many of the chemicals inside cigarettes can trigger dangerous mutations in the body's DNA that make cancers form.
香烟里面许多的化学成分可以引发严重的基因突变，使癌症形成。
Additionally, ingredients like arsenic and nickel may disrupt the process of DNA repair, thus compromising the body's ability to fight many cancers.
此外， 砷和镍等成分也许会破坏DNA修复的过程，从而损害身体对抗许多癌症的能力。
In fact, about one of every three cancer deaths in the United States is caused by smoking.
事实上，在美国三分之一的癌症死亡是吸烟导致的。
And it's not just lung cancer.
而且不只是肺癌。
Smoking can cause cancer in multiple tissues and organs, as well as damaged eyesight and weakened bones.
吸烟既可以使多个组织和器官致癌，又可以使视力受损，甚至骨骼变弱。
It makes it harder for women to get pregnant.
它使女性受孕变得更加困难。
And in men, it can cause erectile dysfunction.
另外会使男性有勃起功能的障碍。
But for those who quit smoking, there's a huge positive upside with almost immediate and long-lasting physical benefits.
但是对于那些戒烟的人来说，有一个巨大的益处，一个几乎可以立即获得，且对身体持续良久的益处。
Just 20 minutes after a smoker's final cigarette, their heart rate and blood pressure begin to return to normal.
吸烟者在抽完最后一支烟的二十分钟后，他们的心跳和血压就开始恢复正常了。
After 12 hours, carbon monoxide levels stabilize, increasing the blood's oxygen-carrying capacity.
十二个小时之后， 一氧化碳达到标准，增加血液携氧能力。
A day after ceasing, heart attack risk begins to decrease as blood pressure and heart rates normalize.
停止一天之后，血压和心跳回归正常，从而降低心脏病突发的危险。
After two days, the nerve endings responsible for smell and taste start to recover.
两天之后，负责嗅觉和味觉的神经末梢开始恢复。
Lungs become healthier after about one month, with less coughing and shortness of breath.
肺在大概一个月之后变得更健康，咳嗽和呼吸急促减少。
The delicate hair-like cilia in the airways and lungs start recovering within weeks, and are restored after 9 months, improving resistance to infection.
几周内，毛发似的纤毛在呼吸道和肺中开始恢复，九个月后结束修复， 提高抗感染能力。
By the one-year anniversary of quitting, heart disease risk plummets to half as blood vessel function improves.
戒烟后的一周年，心脏病风险骤然跌落到一半，同时血管功能改善。
Five years in, the chance of a clot forming dramatically declines, and the risk of stroke continues to reduce.
五年内，血栓形成的几率大大下降，中风风险持续减少。
After ten years, the chances of developing fatal lung cancer go down by 50%, probably because the body's ability to repair DNA is once again restored.
十年后， 罹患致命肺癌的机会下降到50%，大概是因为又一次恢复身体修复DNA的能力。
Fifteen years in, the likelihood of developing coronary heart disease is essentially the same as that of a non-smoker.
十五年内，患冠心病的可能性基本上和非吸烟者相同。
There's no point pretending this is all easy to achieve.
假装这一切都很容易实现是没有意义的。
Quitting can lead to anxiety and depression, resulting from nicotine withdrawal.
戒烟可导致焦虑和抑郁，由于戒断尼古丁造成的。
But fortunately, such effects are usually temporary.
但幸运的是，这种影响通常是暂时的。
And quitting is getting easier, thanks to a growing arsenal of tools.
感谢越来越多的工具库， 戒烟变得越来越容易。
Nicotine replacement therapy through gum, skin patches, lozenges, and sprays may help wean smokers off cigarettes.
口香糖替代尼古丁的疗法，皮肤贴片，含片，和喷雾可以帮助吸烟者戒烟。
They work by stimulating nicotine receptors in the brain and thus preventing withdrawal symptoms, without the addition of other harmful chemicals.
它们通过刺激大脑中的尼古丁受体来起作用，从而防止戒断症状，不含其他有害化学物质。
Counselling and support groups, cognitive behavioral therapy, and moderate intensity exercise also help smokers stay cigarette-free.
咨询和互助小组，认知行为疗法，和中等强度运动也可以帮助吸烟者保持不吸烟的状态。
That's good news, since quitting puts you and your body on the path back to health.
这是一个好消息，从戒烟让你和你的身体回到健康的道路上开始。
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