一天抽几支烟更好?干脆抽一包吧！

A smoke’s no joke.

吸烟可不是闹着玩的。

Smoking five cigarettes a day hurts your lungs nearly as much as smoking two packs, according to new research by Columbia University’s Vagelos College of Physicians and Surgeons.

哥伦比亚大学(Columbia University)瓦杰洛斯外科医师学院(Vagelos College of Physicians and Surgeons)的最新研究显示，每天吸五支烟对肺部的伤害几乎相当于吸两包烟。

They also found that lung function doesn’t restore itself nearly as quickly as you might hope after quitting smoking.

他们还发现，在戒烟后，肺功能恢复的速度并没有你希望的那么快。

For this analysis, scientists looked at the data of 25,352 adults who had their lungs tested at least twice between 1983 to 2014. From there, the researchers zeroed in on their lung function, which is the amount of air a person can breathe in and out.

为了进行这项分析，科学家们查看了25352名成年人的数据，这些人在1983年至2014年间至少进行了两次肺部测试。在此基础上，研究人员开始关注他们的肺功能，即一个人可以吸入和呼出的空气量。

They found that lung function in light smokers declines rapidly — closer to that of a heavy smoker than a nonsmoker. If a nonsmoker loses zero milliliters of lung capacity in a year, a light smoker loses around 7.65 milliliters, and a heavy smoker loses 11.24.

他们发现，轻度吸烟者的肺功能迅速下降——与不吸烟者相比，与重度吸烟者更接近。如果一个不吸烟者在一年内丧失了0毫升的肺活量，一个轻度吸烟者丧失了大约7.65毫升，而一个重度吸烟者丧失了11.24毫升。

“Many people assume that smoking a few cigarettes a day isn’t so bad,” study leader Dr. Elizabeth Oelsner, a professor at the college, says in a press release. “But it turns out that the difference in loss of lung function between someone who smokes five cigarettes a day versus two packs a day is relatively small.”

“许多人认为每天抽几支烟并没有那么糟糕，”研究负责人、该学院教授伊丽莎白·奥尔斯纳博士在一份新闻稿中说。“但事实证明，一天抽五支烟的人与一天抽两包烟的人肺功能丧失的差异相对较小。”

Medically, their findings suggest that light smokers may be at greater risk for developing chronic obstructive pulmonary diseases — for example, bronchitis (hacking cough) or emphysema (trouble breathing) — than we previously realized.

在医学上，他们的发现表明，轻度吸烟者患慢性阻塞性肺病的风险可能比我们之前认识到的更大，例如支气管炎(黑客咳嗽)或肺气肿(呼吸困难)。

They found that quitting does help to preserve lung capacity significantly — by about 8 milliliters per year, compared to that of a current smoker. But lung function doesn’t “normalize,” meaning return to its pre-cigarette baseline, for 30 years.

他们发现，戒烟确实有助于显著地保持肺活量——与还在保持的吸烟者相比，每年大约保持8毫升的肺活量。但30年来，肺功能并没有“正常化”，也就是说恢复到吸烟前的基线水平。