How do gas masks actually work? - George Zaidan

翻译人员: Huey Ing 校对人员: suya f.

You might think of gas masks as clunky, spooky, military-looking devices

你可能会认为防毒面具是笨重、 怪异、军事化的装备。

only found in spy movies or World War I museums.

只有在间谍电影或第一次世界大战 博物馆里才会看到。

But you probably already own a mask that uses remarkably similar technology.

但是你或許已经有了 一款非常相似技术的口罩。

And in the near future, we may need to rely on these filters

在不久的将来， 我们可能需要依赖这些过滤器

as part of our everyday lives.

作为我们日常生活的一部分。

In addition to emerging diseases,

除了新出现的疾病外，

wildfire frequency has more than tripled from 1996 to 2021.

森林火灾的频率从 1996 年 到 2021 年增加了超过两倍

As fires burn longer and cover more land, their smoke affects more people each year.

随着大火燃烧时间的延长 和覆盖面积的增加，

每年受烟雾影响的人口也增加。

Climate change is also causing more hot, sunny days,

气候变化还导致了 更多炎热晴朗的日子，

which accelerates the production of toxic ground level ozone.

这会加速产生产生有毒的地面臭氧。

So, how do these masks work,

这些口罩是如何起作用的呢，

and can they protect us from new and old airborne threats?

和 它们能否保护我们免受新 和旧空气传播的威胁呢？

Well, the first rule of filters is making sure you have a tight seal.

嗯，过滤器的首要规则 是确保有密封严密。

Without that, even the best mask in the world is useless.

否则，即使是世界上 最好的口罩也是无用的.

So assuming your mask is on tight,

所以假设你的口罩戴得很紧，

this technology can capture pollutants in one of two ways:

这项技术可以通过以下 两种方式之一捕获污染物：

filtering them out by size or attracting specific chemical compounds.

通过大小过滤它们或 吸引特定的化学物质。

For an example of the first approach, let’s look at wildfire smoke.

以第一种方法为例， 让我们看看森林火灾烟雾。

When forests burn, they generate a wide variety of chemicals.

当森林燃烧时，它们会产生 各种各样的化学物质。

At close range, there are so many different pollutants

近距离看，有许多不同的污染物

at such high concentrations that no filter could help you—

而且浓度高至于没有 过滤器可以帮到你——

this is why firefighters travel with their own air supply.

这就是为什么消防员 会携带自己的空气供应。

But further away, the situation is different.

但是在更远的地方，情况就不同了。

While there's still a range of chemicals,

尽管仍然存在一系列化学物质，

they’ve mostly aggregated into tiny solid or liquid particles

但它们大部分聚集成聚集成 成直径小于 2.5 微米的

smaller than 2.5 microns in diameter.

微小固体或液体颗粒

This particulate matter is much of what you're seeing and smelling in smoke,

这种颗粒物很大程度上 就是你在烟雾中看到和闻到的，

and it's especially dangerous for children, the elderly,

对儿童、老年人特别危险

and those with respiratory or cardiovascular diseases.

尤其患有呼吸系统疾病 或心血管疾病的人。

Luckily, the majority of these particulates are still large enough

幸运的是，多数的颗粒物足够大到

to be captured by the most basic filters,

足以被最基本的过滤器捕获，

which are made of polypropylene or glass strands

这些过滤器由聚丙烯或玻璃纤维制成

roughly 1/10 the width of a human hair.

大约是人体头发宽度的十分之一。

Under a microscope, they look like a thick forest,

在显微镜下， 它们看起来像一片茂密的森林，

and at this scale, these branches have a special property.

在这种规模下， 这些树枝有一个特殊的性质。

Typically, when you use a sieve,

通常情况下，当你使用筛子时，

you’re filtering out objects larger than the sieve’s holes.

你会筛除比筛子孔大的物体。

But these polypropylene branches can catch particles much smaller

但是这些聚丙烯树枝可以捕获

than the gaps between them.

比它们之间的间隙更小的颗粒。

That’s because, when a particle collides with a thread,

这是因为，当一个颗粒与一个线碰撞时

van der Waals forces cause it to stick as if it were made of Velcro.

范德瓦尔斯力会使其粘在一起， 就像魔术贴做的一样。

Plus, size-based filters can use electrically charged fibers

此外，基于尺寸的过滤器 可以使用带电的纤维

that attract particles not already on a collision course.

來吸引那些尚未进入碰撞轨道的颗粒。

This is how even a simple N95 mask can catch at least 95% of particulate matter.

这就是为什么即使 一个简单的 N95 口罩

也能够捕捉至少95%颗粒物的原理。

And why an N100 mask

以及为什么 N100 口罩

or an air purifier with a high efficiency particulate air filter

或配备高效空气过滤器的空气净化器

can catch at least 99.97% of particulates.

可以捕获至少 99.97% 的颗粒物。

With a tight seal,

通过密封严密，

this level of protection will filter out most airborne pollution.

这种防护级别将 过滤掉大多数空气传播的污染。

Unfortunately, some pollutants are still too small for this approach,

不幸的是，一些污染物仍然太小， 不适合这种方法，

including ozone molecules.

包括臭氧分子。

These are barely bigger than the oxygen that we need to breathe

它们仅仅比我们需要呼吸的氧气大一点

and exposure is associated with asthma, respiratory conditions,

暴露在这些氧气中会导致 哮喘、呼吸系统疾病，

and even premature death.

甚至过早死亡。

Our best chance to filter them are activated carbon masks.

过滤它们的最佳途径是活性炭面罩。

At the microscopic level, activated carbon looks like a vast black honeycomb,

在微观层面上，活性炭 看起来像一个巨大的黑色蜂窝，

and it's highly microporous structure can trap tiny ozone molecules.

其高度微孔结构 可以捕获微小的臭氧分子。

But this material still needs help to capture other pollutants

但是仍然需要这种材料来帮助 捕获其他污染物，

like hydrogen sulfide, chlorine, and ammonia.

例如硫化氢、氯 和氨气。

For these threats, we need to combine the activated carbon

为了应对这些威胁，我们需要将活性炭

with some simple chemistry.

与一些简单的化学物质结合起来。

If the pollutant is acidic, we can infuse the filter with a basic chemical.

如果污染物是酸性的，我们可以在过滤器 中注入一种碱性化学物质。

Then when the two meet, they react, and the gas is trapped.

然后当两者相遇时， 它们会发生反应，气体会被困住

Similarly, we can use acids to trap basic pollutants.

同样，我们可以使用 酸来捕获碱性污染物。

Even with the right mask, it's still smart to check air quality indicators

即使佩戴了正确的口罩， 它仍然是智能检查空气质量指标

and to stay indoors when the threat level is high.

当威胁水平较高时， 待在室内仍然是明智之举。

And just like a mask, you'll want to make sure your house is well sealed.

就像口罩一样， 你需要确保房屋密封良好。

You can do this by closing windows, turning off fans that vent outside,

你可以通过关闭窗户， 关闭排出室外的风扇，

and using HEPA filter equipped air purifiers

和使用配备 HEPA 过滤器的空气净化器

or their cheaper, DIY cousin, the Corsi-Rosenthal box.

或者使用更便宜的DIY版本， 科尔西-罗森塔尔盒子。

Following these guidelines can help us breathe easy

遵循这些指南可以帮助我们放松呼吸

as we work on preventing these pollutants in the first place.

同时帮助我们在第一时间 预防这些污染物。