阳光能杀死病毒吗?乘电梯有多危险?

阳光能杀死病毒吗?乘电梯有多危险?

Can sunlight kill the coronavirus? What about UV light?

阳光能杀死冠状病毒吗?紫外线呢?

Sunlight contains three types of ultraviolet light – UVA, which tans your skin (and ages it) and can cause eye damage; UVB, which burns and also ages skin; and UVC, which is "the most harmful one" because it's quite good at destroying genetic material, explains Juan Leon, a virologist who focuses on environmental health at Emory University.

阳光中含有三种紫外线——长波紫外线(UVA)，它会使你的皮肤晒黑(并使其老化)，还会造成眼睛损伤;中波紫外线(UVB)，会灼伤皮肤，也会使皮肤老化;短波紫外线(UVC)是“最有害的”，因为它很擅长破坏遗传物质。埃默里大学研究环境健康的病毒学家胡安•莱昂解释说。

Luckily, he notes, the sun's UVC rays don't reach us because they are filtered out by Earth's atmosphere.

幸运的是，他指出，太阳的短波紫外线照射不到我们，因为它们被地球的大气层过滤掉了。

Sunlight can be a good disinfectant with other pathogens. Leon notes that's why in the developing world, the World Health Organization recommends sterilizing water by putting it in plastic containers and leaving it outside in the sun for about 5 hours.

阳光对其他病原体来说是很好的消毒剂。莱昂指出，这就是为什么在发展中国家，世界卫生组织建议把水放在塑料容器中消毒，并在阳光下放置约5个小时。

"Right now, there is no data on whether the UVA rays of the sun can inactivate this coronavirus," says Leon. However, research on SARS, another coronavirus closely related to the one causing the current pandemic, found that exposing that virus to UVA light for 15 minutes did nothing to reduce its infectivity, Leon says.

莱昂说:“目前，还没有关于太阳的UVA射线是否能灭活这种冠状病毒的数据。”然而，另一种与引起当前大流行密切相关的冠状病毒SARS的研究发现，将该病毒暴露在UVA光下15分钟并没有减少其传染性，莱昂说。

The results with UVC light were more promising, notes virologist Julia Silva Sobolik, a researcher in Leon's lab at Emory. "UVC for longer durations, over 15 minutes, was found to be more effective at inactivating SARS," she says.

埃默里利昂实验室的研究人员、病毒学家茱莉亚·席尔瓦·索博利克指出，用UVC照射的结果更有希望。”她说：“我们发现，持续时间超过15分钟的UVC在灭活SARS方面更有效。”。

In fact, UVC light is frequently used to sterilize equipment in medical settings, says Leon.

事实上，UVC光经常用于医疗设备的消毒，莱昂说。

If I step into an elevator where an infected person has recently been, could I get the virus?

如果我走进一个最近有感染者呆过的电梯，我会感染病毒吗?

Perhaps you live in a building with an elevator, you ride in one at work or you use one at the grocery store with a full cart. Maybe you're facing an empty elevator and are worried. Could a person with COVID-19 have just been in that space. Should you worry about viral particles in the air?

也许你住在有电梯的大楼里，你在工作的时候乘坐电梯，或者你在杂货店推着满满一车的车使用电梯。也许你正面对着一个空荡荡的电梯，你很担心。有没有一个携带COVID-19的人刚刚在那个地方呆过。你应该担心空气中的病毒颗粒吗?

The Centers for Disease Control and Prevention says current data suggest that the primary mode of transmission is through respiratory droplets from an infected person that can land in the mouths, noses or eyes of people who are nearby or possibly be inhaled into the lungs of those within close proximity.

疾病控制和预防中心说，目前的数据表明，主要的传播方式是通过受感染者的呼吸飞沫，这些飞沫可以落在附近的人的口、鼻或眼睛中，或者可能被吸入到附近人的肺中。

The virus is also believed to spread by touching a contaminated surface and then touching your eyes, nose or mouth.

这种病毒也被认为是通过接触被污染的表面，然后再接触你的眼睛、鼻子或嘴巴来传播的。

What about smaller viral particles in the air? The CDC says the role of "small respirable particles, sometimes called aerosols or droplet nuclei, to close proximity transmission is currently uncertain. However, airborne transmission from person-to-person over long distances is unlikely."

空气中较小的病毒颗粒呢?疾控中心说，“小的可吸入颗粒物，有时称为气溶胶或液滴核，对近距离传播的作用目前还不确定。然而，远距离的人与人之间的空中传播是不太可能的。”

As NPR's Nell Greenfieldboyce has reported, the question of how the virus moves through the air is something scientists are still trying to understand — and disagree about. Even if traces of the virus can be found in the air if an infected person breathes or speaks, it's not clear that the concentration is high enough to transmit the virus.

据NPR新闻的内尔·格林菲尔德·博伊斯报道，关于病毒如何在空气中传播的问题，科学家们仍在努力理解，但仍存在分歧。即使在感染者呼吸或说话时可以在空气中发现病毒的痕迹，也不清楚其浓度是否高到足以传播病毒。

Linsey Marr is an aerosol scientist at Virginia Tech, and she believes that transmission by inhalation of virus in the air is happening.

琳瑟·玛丽是弗吉尼亚理工大学的一位气溶胶科学家，她相信通过吸入空气中的病毒传播正在发生。

"I would be concerned about elevators because they are a confined space," she said in an email interview with NPR. "Many elevators do not seem to have mechanical ventilation, like a fan, beyond the natural ventilation that occurs when the doors open and close."

“我会担心电梯，因为它们是一个封闭的空间，”她在接受美国国家公共电台(NPR)的电子邮件采访时说。“除了门开关门时的自然通风，许多电梯似乎没有像风扇那样的机械通风。”

The main thing to watch out for is the surfaces on the elevator: especially the buttons.

主要注意的是电梯的表面，尤其是按钮。