工作状态不佳？都怪二氧化碳

You might think it's your colleagues or the pressures of work that's getting you down at the office, but new research suggests it could well be the air you're breathing instead. Scientists in the US have found that the concentration of carbon dioxide inside the confined spaces we use every day could be high enough to damage our health.

你也许会认为是你的同事或者是工作压力让你在办公室里萎靡不振，但是新的研究说明可能只是办公室里的空气在作祟。美国的科学家发现我们每天所处的密闭空间中的高浓度二氧化碳会损害我们的健康。

Of course, it's well established that high levels of CO2 are dangerous, not just for human beings but for the planet as a whole, but the new research raises questions about carbon dioxide concentrations that were previously considered harmless.

当然，地球人都知道二氧化碳浓度过高是危险的，不仅对人是这样，对地球也是如此。但是新的研究提出了这样一个问题，那就是之前被人们当作人畜无害的办公室二氧化碳的浓度问题。

The researchers gathered together 24 volunteers and tested their performance in three different simulated office environments. The key metric here is parts-per-million (ppm) of CO2: 5,000 ppm is currently considered the safe limit for an 8-hour workday, while 90,000 ppm will kill you within 5 minutes.

研究者们找来了24名志愿者，把他们分在三个不同的模拟环境下测试他们的反应。这里有个关键的标准，那就是对于8小时工作而言，5000 ppm的二氧化碳目前被人认是安全标准，如果是90000 ppm，那么你5分钟内就会死。

The team experimented with three different levels over the course of a standard 9-to-5 routine: 550 ppm (similar to outdoor levels), 945 ppm (what you would expect in most offices) and 1,400 ppm (denser but still plausible for many offices).

团队按照标准的朝九晚五工作时间准备了三个不同级别的环境：550 ppm(跟室外的浓度差不多)，945 ppm(跟大多数办公室差不多)，和1400 ppm(更浓，但是相当多的办公室都是这样)。

By giving the participants a cognitive test at the end of the day, they were able to spot a clear trend between CO2 levels and brain function. Those working with 945 ppm of carbon dioxide in the air averaged scores that were 15 percent lower than those in a 550 pm room. The unfortunate workers who had to handle levels of 1,440 ppm, meanwhile, performed 50 percent worse than the 550 ppm group. People's ability to use information, respond to a crisis and strategise were hit particularly hard, the researchers said.

在一天结束后，参与者要进行认知测验。在测验中，不同的二氧化碳浓度对大脑功能产生了明显的影响。在二氧化碳浓度为945 ppm环境中工作的人的平均分比550 ppm的要低15%。那些不幸呼吸着1440 ppm的家伙的平均分只有550 ppm的50%。研究者们说，尤其是使用信息，应对危机和策略分析的能力被极大影响了。

Indoor concentrations are affected by many different factors: not just the ventilation installed inside the building and how many windows are open, but also the number of people in the room - because we breath out carbon dioxide - and even how much CO2 is floating around in the neighbouring streets.

有很多因素可以影响室内二氧化碳浓度：除了建筑内的通风设备，打开的窗户数量，还有房间里的人数——因为我们都在呼出二氧化碳——甚至在周围街区的二氧化碳含量。

The researchers, from Harvard and Syracuse University, say carbon dioxide should be considered direct pollutant and not just a marker for other pollutants, plus more research is now required to see how even low levels of CO2 can impair brain function.

来自哈佛大学和锡拉丘兹大学的研究者们说，二氧化碳应该被当做直接污染物，而不仅仅是其他污染物的标记。他们还认为需要进行更多的实验来测试低浓度的二氧化碳对大脑功能的伤害。

"These exposures should be investigated in other indoor environments, such as homes, schools and airplanes, where decrements in cognitive function and decision-making could have significant impacts on productivity, learning and safety," concludes the report, published in the journal Environmental Health Perspectives.

发表在《环境健康展望》杂志上的这篇报告在结论中写道：“这些实验还应该在其他室内环境内进行，比如家里，学校和飞机上，这些地方我们的大脑功能和决策能力的衰减会严重影响生产力，学习能力和安全。”

In the meantime, you might want to ask your boss if you can open up a window.

同时，你也许该跟领导请示下能不能打开窗户了。