Which is better: Soap or hand sanitizer? - Alex Rosenthal and Pall Thordarson

譯者: Melanie Xiaowen Zhang 審譯者: Helen Chang

Your hands, up close, are anything but smooth.

近看之下，你的手一點也不光滑

With peaks and valleys, folds and rifts,

充滿溝壑起伏

there are plenty of hiding places for a virus to stick.

非常便於病毒隱藏

If you then touch your face, the virus can infect you.

然後病毒再透過你觸摸臉時感染

But there are two extraordinarily simple ways you can keep that from happening:

但有兩種非常簡單的預防方法

soap and water, and hand sanitizer.

肥皂和水，以及乾洗手

So which is better?

那麼哪種比較好呢？

The coronavirus that causes COVID-19

冠狀病毒

is one of many viruses whose protective outer surface is made of a lipid bilayer.

是一種由磷脂雙分子層包覆的病毒

These lipids are pin shaped molecules whose heads are attracted to water,

這是一種針狀的脂質分子

頭部親水，尾部厭水

and tails are repulsed by it.

So in water-rich environments, lipids naturally form a shell like this,

所以在富含水分的環境中 脂質自然形成這樣的外殼

with the heads outside and the tails inside.

頭部向外，尾部向內

Their shared reaction to water makes the lipids stick loosely together—

它們對水的共同反應 使它們鬆散地黏合在一起

this is called the hydrophobic effect.

這叫疏水反應

This outer structure helps the molecular machinery of the virus

這種外部結構有助於病毒分子機制

break through cellular membranes and hijack our cells.

打破細胞膜

入侵我們的細胞

But it has thousands upon thousands of weak points

但這種包覆有許多突破口

where the right molecules could pry it apart.

特定分子能撬開

And this is where soap comes in.

這也就是肥皂能進入之處

A single drop of any brand of soap contains quadrillions of molecules

無論任何品牌，一滴肥皂液

就包含了數不盡的「兩親分子」

called amphiphiles, which resemble biological lipids.

形似生物脂質

Their tails, which are similarly repulsed by water,

尾部也具有疏水性

compete for space with the lipids that make up the virus’s shell.

和組成病毒外膜的脂質爭奪空間

But they’re just different enough to break up the regularity of the virus’s membrane,

但其結構上的差異

足以打破病毒外膜分子的排列秩序

making the whole thing come crashing down.

致使整個病毒解體

Those amphiphiles then form bubbles of their own around particles

然後這些兩親分子形成自己的泡泡

圍繞病毒的核糖核酸和蛋白質

including the virus’s RNA and proteins.

Apply water, and you’ll wash that whole bubble away.

沖水就能洗掉這些泡泡

Hand sanitizers work less like a crowbar, and more like an earthquake.

如果說肥皂像撬棍

乾洗手就更像地震

When you surround a coronavirus with water,

在水溶液裡

the hydrophobic effect gives the bonds within the membrane their strength.

冠狀病毒外膜的堅韌 得益於分子結構中的疏水共性

That same effect also holds the big proteins

同樣的疏水共性

也讓形成冠狀病毒尖端的蛋白質固定

that form coronavirus’s spikes in place

and in the shape that enables them to infect your cells.

並讓它維持能夠感染你細胞的形狀

If you dry the virus out in air, it keeps its stability.

風乾環境不會打破這種穩定性

But now surround it with a high concentration of an alcohol,

但在高濃度酒精環境中

like the ethanol or isopropanol found in most hand-sanitizers.

比如乾洗手裡的乙醇或者異丙醇

This makes the hydrophobic effect disappear,

疏水共性被打散

and gives the molecules room to move around.

使得分子有空間可以鬆動

The overall effect is like removing all of the nails and mortar from a house

總體就像拆掉房子的釘子和砂漿

and then hitting it with an earthquake.

然後由地震把房子震散

The cell’s membrane collapses and those spike proteins crumble.

細胞膜瓦解

棘蛋白散落

In either method, the actual process of destroying the virus

這兩種殺毒方式

都只需一兩秒就能起到殺毒作用

happens in just a second or two.

But doctors recommend at least 20 seconds of hand-washing

但醫生建議洗手至少 20 秒

because of the intricate landscape that is your hand.

因為手部表面型態複雜

Soap and sanitizer need to get everywhere, including your palms, fingertips,

肥皂和乾洗手必須全面覆蓋

包含手掌、指尖、手背，以及手指縫

the outsides of your hands, and between your fingers,

to protect you properly.

才能充分起作用

And when it comes to a coronavirus outbreak,

冠狀病毒疫情之下

doctors recommend washing your hands with soap and water whenever possible.

醫生建議儘量用肥皂和水洗手

Even though both approaches are similarly effective at killing the virus,

儘管兩種方式殺毒效果不相上下

soap and water has two benefits:

肥皂和水有兩個優點：

first it washes away any dirt which could otherwise hide virus particles.

首先，可以沖洗掉 可能潛藏病毒的塵土

But more importantly,

更重要的是

it’s simply easier to fully cover your hands with soap and water

肥皂和水便於讓你

充分搓洗 20 秒

for 20 seconds.

Of course, hand sanitizer is more convenient to use on the go.

當然，乾洗手更方便

In the absence of a sink, use the sanitizer as thoroughly as possible

當無處可洗手時

充分搓洗直至乾洗手蒸發乾

and rub your hands together until they’re dry.

Unfortunately, there are billions of people

不幸的是

數十億人沒有乾淨的飲用水

who don’t have access to clean drinking water,

which is a huge problem at any time but especially during an outbreak.

這在任何時候都是大問題 疫情時期尤甚

Researchers and aid groups are working to provide solutions for these communities.

研究員和支援團隊正致力於 給這些社區提供解決方案

One example is a device that uses salt, water, and a car battery

其中一個裝置是用鹽、水和車載電池

to make chlorinated water that kills harmful pathogens

達到氯化消毒作用

and is safe for hand-washing.

製出能用於洗手的水

So wherever possible, soap and water are recommended for a coronavirus,

所以對於冠狀病毒 肥皂和水是條件允許下的首選

but does that mean it's best for every viral outbreak?

但這適用於任何病毒疫情嗎？

Not necessarily.

不一定

Many common colds are caused by rhinoviruses

很多引起普通感冒的鼻病毒

that have a geometric protein structure called a capsid

外層包覆是一種名為 衣殼的幾合蛋白結構

instead of a lipid membrane.

而不是脂質膜

The capsid doesn't have nearly as many weak points

衣殼沒有那麼多

肥皂兩親分子能撬開的突破口

where soap amphiphiles can pry it apart,

so it takes longer for soap to be effective.

所以肥皂要搓洗很久才能起作用

However some of its surface proteins are still vulnerable

但乾洗手的破壞作用

to the destabilizing effect of hand sanitizer.

依然能作用於它的某些表面蛋白

In this and similar cases, hand sanitizer may be more effective,

在這類情況下 乾洗手也許就更好用

especially if you then wash your hands to remove residual particles.

尤其是如果你能後續再沖洗掉殘留物

The best way to know which to use for any given outbreak

如何得知任何疫情下有效的清潔方式

is to do what's best for all things illness-related:

也是對於任何疾病相關問題的原則：

follow the advice of accredited medical professionals.

遵醫囑