FOR decades, doctors and governments have been trying to wean smokers from their habit. It is a tricky task. Nicotine isas addictive as heroin and cocaine. There are plenty of officially endorsed methods for quitting. People can try inhalators, gum, lozenges, patches, nasalsprays and prescription drugs. All can help, but few replicate all the physical and social rituals that surround cigarettes. That limits how appealing they are to committed smokers.
幾十年來，醫生和政府一直在努力讓菸民戒除吸菸習慣。這是一件很難辦的 事情。尼古丁與海洛因、古柯鹼一樣容易成癮。經過官方認證的戒菸方法有很多， 人們可以使用霧化吸入器、口香糖、含片、貼片、噴鼻劑和處方藥等來嘗試戒菸。這些方法可能都有所助益，但從生理和社會角度看，很少能讓人產生與香菸完全 相同的體驗，因此對於菸癮很大的人來說，它們的吸引力有限。
It was into this mix that e-cigarettes arrived about a decade ago. Unlike ordinary cigarettes, which rely on burning to baccoto deliver their payload, e-cigarettes use an electric charge to vaporise a dose of nicotine (accompanied, often, by various flavouring chemicals). They have proved extremely popular, particularly in America, Britain and Japan. Public-health officials have been quick to conclude that they are much better than smoking. Consumers, says Robert West, a professor of health psychology at University College London, are 「voting with their lungs」.
大約十年前，電子菸躋身此類戒菸用品行列。普通香菸通過菸草的燃燒來釋 放物質，電子菸則不同，它是用電荷氣化一定劑量的尼古丁（隨之釋放的還有各 種香味的化學物質）。事實證明，電子菸非常受歡迎，特別是在美國、英國和日本。公共衛生官員迅速得出結論：抽電子菸比抽香菸要好得多。倫敦大學學院健康心理學教授羅伯特•韋斯特說，消費者「正在用他們的肺投票」。
Still, not everyone is happy. E-cigarettes are new, so information about their effects is still scarce. Others worry about who is using them. The Food and Drug Administration, an American regulator, says it has data showing an 「epidemic」 of vaping among teenagers which it will release in the coming months. Earlier this month it put e-cigarette firms on notice that they must try to combat underage use of their products or face sanction. How worried should vapers—or their parents—be?
然而，並不是每個人都開心。電子菸屬於新生事物，因此與其效果相關的資 訊仍然少之又少。還有人對誰在使用電子菸感到擔憂。美國監管機構——食品及藥物管理局（FDA）稱其已有數據顯示，青少年開始「流行」抽電子菸。FDA 將 在未來幾個月裡公布這一數據。本月早些時候，FDA 對電子菸公司發出警告，要 求他們必須防止未成年人使用其產品，否則將面臨處罰。電子菸民或者他們的父 母到底會有多擔心呢？
The chemistry is the best place to start.Cigarette smoke is genuinely nasty stuff. It contains about 70 carcinogens, as wellas carbon monoxide (a poison), particulates, toxic heavy metals such as cadmium and arsenic, oxidising chemicals and assorted other organic compounds.
我們最好先從化學說起。香菸煙霧真的非常骯髒，含有約70 種致癌物，此 外還有一氧化碳（有毒物質）、顆粒物、有毒重金屬（如鎘和砷）、氧化劑以及各種其他有機化合物。
The composition of e-cigarette vapourvaries between brands. A best guess suggests that, instead of the thousands of different compounds in cigarette smoke, it contains merely hundreds. Its maining redients—propylene glycol and glycerol—are thought to be mostly harmless when inhaled. But that is not certain. People with chronic exposure to special-effect fogs used in theatres—which contain propylene glycol—have reported respiratory problems. Nitrosamines, a carcinogenic family of chemicals, have been found in e-cigarette vapour, albeit at levels low enough to be deemed insignificant. Metallic particles from the device’s heating element, such as nickel and cadmium, are also a concern.
就電子菸而言，氣化物化學成分因品牌而異。最樂觀的估測是，香菸煙霧中 不同的化合物是數以千計，而它僅是數以百計，其主要成分丙二醇和甘油，被認為吸入後通常不會對人體產生毒害。不過，這也不一定。據報告，長期接觸含有 丙二醇的劇場特效煙霧的人出現了呼吸道疾病。在電子菸霧中，人們還發現了一 類致癌化學物質——亞硝胺，儘管其含量非常少，以至於無關緊要。該設備加熱元件產生的金屬顆粒，如鎳和鎘，同樣值得關注。
Some studies have found that e-cigarettevapour can contain high levels of
unambiguously nasty chemicals such as formaldehyde, acetaldehyde and acrolein, all derived from other ingredients that have been exposed to high temperatures.The vapour also contains free radicals, highly oxidising substances which can damage tissue or DNA, and which are thoughtto come mostly from flavourings. According to work published this January flavourings such as cinnamon, vanilla and butter generate the most.
一些研究發現，電子菸霧中可能含有濃度很高而且無疑十分有害的化學物質， 比如甲醛、乙醛和丙烯醛，它們均是在高溫條件下從其他成分中分解而來的。氣霧中還包含氧化性極強的自由基，會對人體組織或DNA 造成損傷。這些自由基 據稱大多來自調味成分。今年 1 月發布的研究成果顯示，肉桂、香草、黃油等調 味料產生的自由基最多。
Several studies in mice have confirmed that the vapour can induce an inflammatory response in the lungs. In June, for example, Laura Crotty Alexander at the University of California San Diegoand her colleagues published results which showed that e-cigarette vapour has avariety of unpleasant effects, inducing kidney dysfunction and a thickening and scarring of connective tissue in their hearts called fibrosis. Her data suggest that the vapour may also be disrupting the epithelial barrier that lines the lungs,triggering inflammation. They speculate that this could make it easier for pathogenslike bacteria to take hold. That would fit with recent work by Lisa Miyashita at Queen Mary University of London, which found that vaping makes cells lining the airways stickier and more susceptible to bacterial colonisation.
幾項在老鼠身上的研究證實，電子菸霧可誘發肺部炎症反應。例如，2018 年 6 月，加州大學聖地牙哥分校的蘿拉•克羅蒂•亞歷山大及其同事發表的研究結果表明，電子菸霧能產生諸多不良影響，會引發腎功能障礙，並導致心臟結締組 織增厚和瘢痕形成即纖維化。她的數據顯示，氣霧還可能會破壞肺內的上皮細胞 屏障，引起炎症。他們推測，這會讓細菌之類的病原體更易在人體內紮根。無獨有偶，倫敦大學瑪麗女王學院的宮下麗莎最新研究也發現，氣霧會讓氣道壁上的 細胞粘度增加，更易遭細菌侵襲。
Puffedup來一口電子菸
It all sounds worrying. But a dose of scepticism is useful too. One alarming study in August said that e-cigarette users aremore likely to have been diagnosed with cardiovascular disease. But many vapers have smoked in the past, or still do. The paper may have been picking up old harms from smoking, rather than new ones from vaping. Many think that the toxic nature of e-cigarette vapour may have been exaggerated by unrealistic laboratory conditions. Overheating the fluid creates an unpleasant taste that users actively avoid.Lab tests may heat the fluid more vigorously than real vapers do, for example.
一切聽上去都讓人憂心忡忡，不過一定的質疑也是有益處的。8 月一項驚人 的研究稱，電子菸民罹患心血管疾病的可能性更大。但是，許多電子菸民過去乃至現在仍在抽香菸。這份報告統計的或許只是抽香菸引發的陳舊性損傷，而不是 因電子菸霧所致的新發損傷。許多人認為，電子菸霧的毒性可能因實驗室條件脫 離實際而被誇大了。比如說，液體過熱會產生令人不適的氣味，菸民會主動避免。實驗中可能會對液體加熱過度，而實際上電子菸民並不會如此。
The last piece of the puzzle is thenicotine. Besides being addictive, it is known to have an adverse affect all around thebody. But the current source of concern isits effects on children. For instance, work in animals suggests that exposure tonic otine could be bad for adolescentbrains, making users more susceptible to other addictive substances later in life.This could be one reason why human smokers who start young have higher rates of addiction as adults. It might also mean that children who vape risk a lifelong addiction to nicotine, and may even start smoking. But, says Dr West, these concerns have not yet been borne out by epidemiological studies.
最後一個謎題是「尼古丁」。 眾所周知，除了易於成癮，尼古丁還會對全身造成不良影響。不過就目前來看，人們主要擔心的是其對兒童的影響。例如， 動物研究表明，長期接觸尼古丁對青春期的大腦有害，使青少年在以後的生活中， 更容易對其他成癮物質產生依賴。這可能也是從小就開始吸菸的人成年後成癮率更高的原因之一。此外，它還意味著，抽電子菸的兒童存在終生依賴尼古丁的風 險，甚至會開始吸菸。但是，韋斯特說，這些令人擔憂的情況至今尚未得到流行 病學研究證實。
Smoking during adolescence has also been associated with lasting cognitive and behavioural impairments, including on working memory and attention. Animal tests suggest that exposure to nicotine specifically could explain at least some of that effect. All this forms the scientific backdrop to the FDA’s worries about the effects of vaping among the young.
青春期吸菸也與包括機械記憶、注意力在內的認知和行為持續性障礙存在關 聯。動物實驗表明，特異性接觸尼古丁後至少會出現其中部分問題。從所有這些科學研究來看，擔心電子菸給年輕人帶來的影響，FDA並非杞人憂天。
Getting definitive answers will take time. Epidemiology is a tricky business. All
sorts of confounding factors and overlooked connections can skew conclusions.Smoking stands out in medical history as apastime which is so unambiguously bad for you that the signal cuts through almost any amount of noise. The truth about e-cigarettes will take longer to tease out.
獲知明確的答案尚需時日。流行病學研究非常複雜，各種混雜的因素及被忽 視的關聯都會讓結論有失偏頗。醫學早已證實，吸菸顯而易見只是一種消遣方式， 其對人體的有害性幾乎無可爭辯。至於電子菸，揭開真面目還需要更長的時間。
That may sound frustratingly vague. But it points to at least one clear conclusion—whether it is harmless or only moderately bad for you, vaping is almost certainly safer than smoking. Thatis a message which needs spreading. In Britain about a third of smokers say they have not tried vaping because they are worried about its safety and addictiveness.This attachment to a known evil is self-defeating. At least for now, thee-cigarette looks like a useful innovation in public health.
如此含混不清的說法聽起來不免讓人沮喪，不過它至少得出一個清晰的結論： 抽電子菸不論是無害還是稍有害處，幾乎可以肯定比抽香菸更安全。這一信息需要廣而播之。英國三分之一的菸民表示，他們之所以沒有嘗試電子菸，是因為對 其安全性和成癮性有所顧慮。明知吸菸之禍害卻依然故我，到最後只能自食其果。 最起碼就現在來看，電子菸在公共衛生領域算是一種有益的創新了。