You can tell the dude sitting next to you in the movie theater is a smoker or vaper; you can smell it on his clothes. But since he's not lighting¹ up and puffing² smoke your way, it's OK, right?

你可以辨别出电影院里坐在你旁边的人吸不吸烟，你可以从他的衣服上闻到烟味。但只要他不点燃香烟并向着你吞云吐雾，就不会危害你的健康，对吗？

Not at all.

完全不对。

A new study out of Yale University says thirdhand smoke -- the tobacco contaminants that adhere to walls, bedding, carpet and other surfaces until a room smells like an ashtray³ -- can actually cling to a smoker's body and clothes as well.

耶鲁大学的一项新研究指出，三手烟，即吸附在墙壁、床单被褥、地毯和其他表面的烟草污染物，让房间闻起来像烟灰缸，事实上也会附着在吸烟者的身体和衣服上。

Those potentially toxic⁴ chemicals, including nicotine⁵, can then be released into environments where smoking has never occurred, like your movie theater, according to the study.

研究发现，（吸附在吸烟者身上的）包括尼古丁在内的这些潜在的有毒化学物质之后会被释放到没人吸过烟的环境中，比如电影院。

Even more disturbing: The study found those chemical exposure levels could be the equivalent of between one and 10 cigarettes by the end of the movie.

更让人困扰的是：研究发现，看完一场电影，暴露在这些化学物质中所受的危害相当于吸了1到10根烟。

"People are substantial carriers of thirdhand smoke contaminants to other environments," said study author Drew Gentner, an associate professor of chemical and environmental engineering at Yale.

研究报告的作者、耶鲁大学化学与环境工程学副教授德鲁·金特纳说：“人们是将三手烟污染物携带到其他环境的重要载体。”

The study, published in the journal Science Advances, may be the first to show that people can transmit nicotine and other potentially toxic chemicals via their clothing after smoking, he said.

他说，这项发表在《科学进展》期刊上的研究可能是第一个表明人们吸烟后可以通过衣服来传播尼古丁和其他潜在有毒化学物质的研究。

"That was the unique part of this study," Gentner continued. "We were surprised by the wide array of hazardous⁶ volatile⁷ organic compounds that were off-gassing from the audience -- including some that are known to be carcinogens in people, such as benzene and formaldehyde."

金特纳继续说道：“这是本研究的一个独特之处。观众身上散发出的挥发性有害有机化合物——包括苯和甲醛等已知致癌物——种类之多让我们感到惊讶。”

Thirdhand "smoke" isn't actually smoke at all. It's the residue⁸ of nicotine and other chemicals in tobacco, some of which are toxic, that remain long after active smoking is over.

三手烟其实根本不是烟。它是香烟中的尼古丁和其他化学物质的残留，其中一些化学物质是有毒的，在吸完烟很久后还能留存。

Some of these chemicals stick to surfaces, and others attach to dust particles. Still others often penetrate⁹ deep into wallboard, drapes and upholstery. As the compounds linger, they may react with oxidants or other particles in the room's atmosphere. The chemical reactions can create potentially harmful byproducts that can become airborne.

有些化学物质会附着在表面上，其他一些则会附着在粉尘上。还有一些化学物质经常会渗入墙板、窗帘和家具装饰品。在化合物停留期间，它们可能会和室内空气中的氧化物或其他颗粒发生化学反应。这些化学反应会产生有潜在危害的副产物，并通过空气传播。

Science has known about this type of environmental pollution for years, sparking the creation of smoking and non-smoking rooms at hotels, restaurants and the like.

这种环境污染早在多年前就已被科学家知晓，并催生出酒店、餐厅等场所的吸烟室和无烟室。

But thirdhand smoke has also been found in environments which were not known to be contaminated by smokers¹⁰, which led researchers to ask how that could happen.

但是在未被吸烟者污染过的环境中也发现了三手烟，这让研究人员发问：这是怎么发生的？

To find out, Gentner and some of his PhD students set up an experiment in a movie theater that had not allowed smoking for more than 15 years. They supplied fresh air into the theater, making sure that no smoking or other contaminants entered the space.

为了找寻答案，金特纳和他的一些博士生在一家禁烟超过15年的电影院开展了一个实验。他们给影院输入新鲜空气，确保烟雾和其他污染物不进入这一空间。

Sophisticated equipment measured airborne particles before and after moviegoers arrived. Right away, they saw a huge spike¹¹ in levels of hazardous chemicals.

在观众到达影院前后，他们用精密的仪器测量了空气中的颗粒物。很快，他们就看见有害化学物质的水平大幅上升。

As people came into the theater, the concentrations went up, and then decreased over time, Gentner said.

金特纳说，随着人们进入影院，有害化学物质的浓度上升了，但随着时间过去又下降了。

"But they didn't completely disappear after the audience left," he added. "In many cases, the persistent¹² contamination was observable the following day in the unoccupied theater."

“但是这些有害化学物质没有在观众离去后完全消失，”他补充道，“很多情况下，在影院无人时，第二天依然可以观察到持续的污染。”

The testing continued over a four-day period across different movie genres¹³. Perhaps not surprisingly, levels of nicotine and other chemicals were lower in the G-rated movies geared toward kids.

接下来，研究人员在四天时间内针对不同的影片类型继续进行测试。结果发现，尼古丁和其他化学物质的水平在播放面向儿童的G级电影时更低，这也许并不令人意外。

"Despite cases where we had audiences of over 200 people for some of the G-rated movies, the pollutants¹⁴ were much larger for R-rated films, even with smaller audiences," Gentner said. "Those movies would likely draw older audiences that might be more likely to smoke."

“部分G级电影有超过200人观看，但播放R级电影时，即使观众人数较少，产生的污染物水平也要高得多，”金特纳说，“R级电影更可能吸引年纪较大的观众，这些人更可能吸烟。”

Despite declines in smoking in some developed nations, there are still over a billion smokers worldwide, according to the World Health Organization.

世界卫生组织称，尽管一些发达国家的吸烟率降低了，但世界范围内还有超10亿名吸烟者。

"That billion smokers contribute to about 880,000 deaths from secondhand smoke," said Dr. Jagat Narula, a cardiologist at Mount Sinai Morningside in New York City who researches the health impact of smoking. "I call it a form of murder."

纽约市西奈山晨边医院的心脏病科医师雅佳特·纳如拉说：“这10亿吸烟者导致约88万人死于二手烟。我把这种行为称为谋杀的一种。”纳如拉医生研究吸烟对健康的影响。

Learning about the Yale study's findings on the level of off-gassing from human bodies and clothing was not surprising, said Narula, who was not involved in the study.

在了解耶鲁大学对于人体和衣服散发三手烟的发现后，没有参与该研究的纳如拉表示并不惊讶。

"But it is disturbing," he said. "Numerous reports have shown that there is no safe level of exposure to secondhand smoke.

“但是这让人感到不安，”他说，“许多报告显示无论吸入的二手烟量有多小，都是不安全的。”

"If future research replicates¹⁵ these findings on thirdhand smoke, it means that smokers could potentially still do harm even if the act of smoking took place in a different space."

“如果未来的研究证实了关于三手烟的这一发现，这意味着即使吸烟者在另一个空间吸烟，也会对他人造成潜在危害。”