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Are negative ions good for you?

負離子對你有益處嗎？

Normally I'd dismiss such a question out of hand.

通常，我會不假思索地否定這樣的問題

In fact that's exactly what I did when a friend brought

事實上，我的確這麼做了 當我朋友一個月前提起這件事的時候

it up about a month ago. But he was insistent he said no this is for real

但他卻堅持說"不，這是真的，這背後是有科學的"

there's science behind it.

所以我，看這~~ 我找到了這個

And so I looked into it and I found this.

數百篇已發表，經同儕審查的科學研究 關於離子的生物效應

There are literally hundreds of published peer-reviewed scientific studies on the

這是一個研究主體，約在一個世紀前開始並持續到今天

biological effects of ions.

而這些，這只是其中的一小部分

It's a body of research that begins about a century

現在這些研究不只是關於任何舊離子 它們還與大氣離子或空氣離子有關

ago and continues to the present day.

雖然結果並沒有一致 但都是用這樣的前提開始的：

And this is just a fraction of it.

正離子讓我們感覺不好 負離子讓我們感覺良好。

Now these studies aren't just about any old ions they're about atmospheric ions or air

所以在這個影片中我想要深入探討這個

ions. And although the results are not uniform, they all begin with the premise

這些是喜馬拉雅鹽燈

that positive ions make us feel bad and negative ions make us feel good.

隨著燈泡的熱量 它將負離子釋放到空氣中

So in this video I want to get to the bottom of this.

當然負離子你吸入後 在你的體內產生血清素

These are Himalayan salt lamps.

而血清素就像你全身裡和所有生物的主要神經傳導物質 就是這樣讓你感覺美好

With the heat from the light bulb, it releases negative ions into the air and of

真棒。

course negative ions are what you breathe in and produce the serotonin in

我可以跳到這邊一下下嗎?

the body and in serotonin is like the primary neurotransmitter in your whole

當我第一次聽到這一切關於大氣離子

body and all living things and that's what makes you feel good...

我的第一個念頭是~~

awesome.

為什麼我們應該期待那裡大氣中有很多離子？

Can I jump in here for a second. When I first heard all this business

讓我們回顧一下

about atmospheric ions, my first thought was 'why should we expect there to be

一個離子只是 一個原子 或 一個分子 得到 或 失去 電子

many ions in the atmosphere at all?' I mean to recap, an ion is just an atom or

如果它失去了一個電子，它就是一個陽離子

a molecule that has gained or lost an electron. If it loses an electron it's a

如果它獲得了電子，它就變成負離子

positive ion. If it gains an electron it becomes a negative ion. But here's the

但~事情是這樣的：不像電荷吸引 所以在大氣中移動時

thing: unlike charges attract. So moving about in the atmosphere I'd

我預期正離子和負離子找到彼此 然後BOOM!!

expect the positive and negative ions to find each other and then BOOM they're

它們回到了中性

back to being neutral.

然而，事實證明

However, as it turns out there are some processes that

有一些機制正不斷產生大氣離子

are constantly generating atmospheric ions.

例如，宇宙射線

For example cosmic rays. These are

穿梭宇宙的這些高能粒子

highly energetic particles from across the universe that slam into our

它們衝入大氣並轉移他們的能量進空氣中 在此過程中產生離子

atmosphere and transfer their energy to the air, creating ions in the process.

宇宙射線被認為在地表 每立方公分(1cc)可產生約500個離子

Cosmic rays are thought to create around 500 ions per cubic

事實上，它們是海洋上的最主要的離子產生來源。

centimeter at ground level. In fact they're the most significant source of

但這裡在陸地上，還有其他離子化來源

ions generated over the oceans.

像是天然的放射線

But here on land there are other sources of

有這些長壽鈾和釷的同位素

ionization, things like natural radioactivity.

與他們的衰變產物

There are these long-lived

可以吐出高能粒子如α，β還有γ射線。

isotopes of uranium and thorium and their decay products that can spit out

這些會電離化空氣，它們依地區變化很大

highly energetic particles in the form of alpha, beta and gamma rays.

但他們可以貢獻每立方公分(cc)數百到數千個離子

These ionize the air and they vary widely from place to place but they can contribute

如果你向我推薦其中一個 像是~~有最多的負離子

hundreds up to many thousands of ions per cubic centimeter.

你認為哪一個？

If you were to recommend one of these to me that like has the most negative ions, er, which one

我想會是最熱的這個

do you think?

因為來自燈泡的熱量會產生熱量 從而在鹽中產生反應

I would just go for which one's hottest. -yeah?

得到它了。

Because it's the heat from the lightbulb that creates the heat, which makes the reaction in the salt.

哇！這個很棒。 是嗎？這將是完美的

Got it.

接著，你有雷雨 每道雷擊會產生豐沛的離子

Wow! This one's great. Yeah? This would just be perfect

也許，其中一個更讓人驚訝的負離子來源，是瀑布

And then you have thunderstorms. Each lightning strike generates copious

隨著高速的水滴相互碰或撞擊濕潤的表面

amounts of ions.

水分子產生這種帶電霧氣

Perhaps one of the more surprising sources of negative ions is waterfalls.

帶著負離子並可以轉移到周圍的空氣中

As water droplets collide with each other or with wetted surfaces

依據你與瀑布的距離，離子含量可以達到每cc數萬個

with high velocity, the water molecules create this electrified spray with

海浪拍打在岸上也有一樣的效果

negative ions that can be transferred to the air around it.

(Ronald 與 Maxine Linde 全球環境科學中心)

Depending on your distance from the waterfall, ion levels can reach tens of thousands of ions per

哈囉！ 嗨Derek，你好嗎？

cubic centimeter. And the same effect occurs with ocean waves crashing on shore.

很好，我我可以給你這個嗎？ 當然~

Hello! Hi Derek, how are you?

所以我想知道的是有多少負離子從這燈出現? 還有時機點

Good, Can I give you that? Sure.

我們有一種質譜的技術可以測量從固體跑出來的負離子

So what I want to know is how many negative ions are there coming off that lamp when it's on?

所以我們可以嘗試一下。

We have a technique involving mass spectrometry that measures negative ions coming off

你是離子專家嗎？

of solids and so we can give it a try.

我已經研究離子55年了

Are you an ion expert? I've been studying

而且寫了數百篇關於離子方面的論文了

ions for 55 years. Whoa

這是我的鹽燈，它意味著可以給我們很多負離子

And have written hundreds of papers on all

你能告訴我 它是否有提供了一些負離子？

aspects of ions.

我們來看看，我們使用這個東西

So this is my salt lamp. it's meant to give us lots of negative

這是質譜儀的入口處於大氣壓力下

ions. Can you tell me whether it's giving us some negative ions?

如果那裡有離子，我們就能偵測到它們

We're gonna have a look and the thing we're utilizing here is that the inlet to this mass

所以這就像..是...某種針對離子的電子鼻或什麼的?

spectrometer is at atmospheric pressure and if there's ions there we'll be able

(Derek:聞出離子) 你可以把它想像成離子的鼻子 是的 聞出離子

to detect them. So this is like.. is it is it kind of like an electronic nose or

燈旁邊是離子採樣錐體

something for ions? sniffs the ions. - You could think of it as a nose for ions. Yeah, yeah, sniffs the ions. -OK

我的意思是 它還沒開始但

The lamp is next to the ion sampling cone. I mean it's not on yet but we'll see

我們將會看到 如果有任何離子來自它

if there's any ions coming from it. -No so this display here this would be this

所以這裡顯示的就是這個是我們的質荷比軸(m/z-axis)

is our mass to charge axis here so how how heavy they are in molecular

實際上分子量有多少 如果有離子生成，我們會在螢幕上看到訊號

weight essentially and if there's ions being formed we're gonna see some signal

會不會有一些峰值？一些峰值，是的

on this screen. -There'd be like some peaks? Some peaks, yeah

它需要預熱嗎？

Now does it need to warm up?

我認為這是個好主意~ 是的~

er -I think that's the idea, yeah.

現在~有些地方離子濃度自然就是比較低

Now there are some places that do naturally

就是~房屋和商辦的內部。

have lower concentrations of ions, namely the interiors of houses and businesses.

因為這些結構提供了一些屏蔽效果 阻擋宇宙射線和天然輻射線

Because these structures provide some shielding from the cosmic rays and from

加上~如果你有金屬管道和空調

the natural radioactivity. Plus if you have metal ducting and air

許多帶電離子會困在管道中

conditioning, well some of those charged ions will get stuck in the ducts

所以一般家庭與辦公室內部的離子濃度 可以低至每cc 100~200個

so typically levels inside homes and businesses can be as low as around 100

通常在污染區域離子濃度也會比較低 在大城市或工廠周圍

or 200 ions per cubic centimeter.

那是因為離子實際上依附在污染物或氣溶膠上

Ion concentrations are also typically lower

所以它們大氣中活得不久

in polluted areas, in big cities or around factories. And that's because the

所以~我們住在比祖先更少離子濃度的環境 的主張 是對的

ions actually cling to those pollutants or the aerosols and so they

如果你認為在瀑布、海洋、雷雨周圍

don't live as long in the atmosphere.

比起你在汙染的城市或大工廠邊感覺更好了

So the assertion that we live in

也許這就是科學家一直在研究 負離子對人類健康的影響將近一世紀的原因

environments with fewer ions than our ancestors is true.

所以讓我們思考一下這個證據......

If you're thinking that you feel better around waterfalls and oceans and after

在一項研究中，人們患有季節性情緒失調(SAD)

thunderstorms than you do in polluted cities or around big factories, well

隨機分配到三組其一的治療組

maybe that's the reason why scientists have been studying the effects of

明亮的光療法；高濃度的負離子；低濃度的負離子

negative ions on human health for nearly a century.

他們發現明亮的光療法和高密度的負離子兩者

So let's consider the evidence...

是獨立對抗抑鬱產生作用，但低密度負離子則不是

In one study people suffering from seasonal affective disorder were

在另一項研究中，參與者處於高濃度負離子的環境

randomly assigned to one of three treatment groups: bright light therapy

擁有較快的反應時間

high concentrations of negative ions or low concentrations of negative ions.

並回報在環境空氣控制下，精力更充沛

They found that both bright light therapy and high-density negative ions independently

如果這一切聽起來太過主觀

produced antidepressant effects, but not low density negative ions.

腦波圖(EEG)實驗顯示人暴露在高濃度負離子

In another study, participants in a high-density negative ion environment had significantly faster

有一個頻率較慢但震幅較高的α波頻率

reaction times and reported being more energetic than those in an ambient air control.

參與者也回饋，增進放鬆、警覺性與工作能力

Now if all this sounds too subjective, EEG experiments showed people

並且發現正離子有著相反的結果

exposed to high-density negative ions had a slower alpha wave frequency with

在一項研究中，志願者暴露於高濃度的正離子兩個小時

higher amplitude. Participants also reported increased relaxation, alertness,

焦慮和興奮的症狀 顯著增加

and improved working capacity. And opposite results have been found with

在暴露期間，血清5-羥色胺濃度也顯著升高

positive ions. In one study volunteers were exposed to high concentrations of

現實世界的工作環境甚至已經採取了這種做法

positive ions for two hours. Symptoms of anxiety and excitement significantly

空氣電離器被安裝在辦公室建築裡的空調中

increased. During the time of exposure serum serotonin levels also increased

並週期性的開關超過12週

significantly. This has even been taken into real-world work environments. An

當電離器釋放負離子，職員們表示頭痛減少了50％

air ionizer was fitted to the air-conditioning unit in an office

也回報 警覺性增強、感覺空氣清新、自我感受環境溫暖

building and periodically turned on and off over 12 weeks. When the ionizer was

感覺很熱，它已經開了一小時了?

pumping out negative ions, workers reported 50% fewer headaches. They also

所以問題是可以鹽燈產生負離子嗎？

reported increased alertness, perceived atmospheric freshness, and environmental

來測試一下負離子吧~ 再看一次吧

and personal warmth. It's feeling it's feeling pretty hot it's been on for an

看起來不像

hour? yeah. So the question is can a salt lamp generate negative ions? let's check

但是 我的意思 這甚至不像背景訊號

for negative ions? -let's look again

的確不是......

Doesn't look like it.

甚至它就像沒有放在那裡

But, I mean there's not even like a background.

所以在測試這個鹽燈後你的結論是

No, there's not... it's just like

它沒有產生負離子 我們確認無法偵測出任何負離子

it's not even sitting there.

關於鹽燈產生負離子的的想法

So your conclusion after testing this device is

是水分子落在表面上

that it's producing no negative ions. -We're certainly not able to detect any negative ions.

並解離出來自晶格的氯離子

The idea for how these salt lamps are meant to create negative

但要問任何化學家他們的鹽辦得到嗎?

ions is that water molecules are meant to land on the surface and liberate

他們會告訴你所需的能量太高了 所以並不會發生

chloride ions from the lattice.

我發現諷刺的是真的有加熱就可以產生離子的晶體

But ask any chemist worth their salt and they'll

只是鹽並沒有正確的晶體可以運作

tell you the energy required to do this is way too high so it just doesn't

寶石碧璽(電氣石)可以辦得到

happen.

這些樣本價值數千美元。

What I find ironic is that there are crystals which when heated will

電氣石的結構讓你如果加熱它就會膨脹

produce ions. It's just that salt doesn't have the

他實際上會在晶體面上發展成電荷

right crystal structure to make this work. The gemstone tourmaline does.

在晶體面之間放電，穿入空氣並形成離子

Those samples are worth many thousands of dollars.

然後電荷可以轉移到任何存在空氣中的有機分子

Tourmaline has a structure such that if you heat it and cause it to expand, it will actually

五度的變化足以產生離子

develop an electric charge on the faces of the of the crystal you have

我才發現這特別的是有一種晶體，一種材料

discharges between those faces, breakdown in air and forming ions and that

你可以透過加熱來創造負離子，起來並產生負離子

charge then can get transferred to any organic molecule that's present in the air.

所以，一般人不會有"電氣石燈"的原因

A five degree change was enough to generate ions. -I just find this

只是因為電氣石真的很貴嗎？

extraordinary that there is a crystal, there is a material that you could heat

(點頭 點頭 點頭 ...)

up and create negative ions. So the reason people wouldn't have tourmaline

好的，所以我們沒有在鹽燈上看到任何離子

lamps is because tourmaline is just really expensive?

但我帶來了某個東西

okay so we didn't get

我認為可能會帶給我們一些離子 這是一台離子空氣清淨機

any ions off of the salt lamp but I brought something along that I think

當這個產品是第一次推出後它銷售了200萬台

might give us some ions. This is an ionic air purifier. When this product was first

它使用高電壓去電離化空氣並加速這些離子去產生你能感受到的微風

launched it sold a two million units. It works by using high voltage to ionize

不使用任何活動部件

the air and accelerate those ions to produce the light breeze you can feel

好，我感到一陣微風從它吹出 那應該進入了~噴嘴？

without any moving parts. -Okay I feel a breeze coming out of it

我們已經把它指向了我們的離子入口~這樣很好

and that should be going into the nozzle? we've got it pointed right at our ion

我們此刻似乎是看到一些離子

Inlet so that's good.

我們有一個離子微風就在源頭旁邊

We seem to be seeing some ions at the moment and we

這些是負離子

have the ionic breeze right up next to the source so.

這些都是負離子

These are negative ions

所以，如果你想要在房子裡有負離子

these are negative ions.

你需要的不是鹽燈，而是一台離子空氣清淨機

So if you want negative ions what you need in your

在你急著買一台之前，我需要警告你的是

house is not a salt lamp, it's an ionic air purifier.

產生這些離子也造成了一個不幸的副產品：臭氧

Before you rush out to buy

所以現在我們是測量到約十億分之17 切確的臭氧

one I should warn you that generating these ions produces an unfortunate

我們把它放到前面，看看我們量到的臭氧是否增加

by-product:

它超過80了

ozone. So right now we're measuring about 17 parts per billion

我們實際上處於霧霾警報的濃度

actually of ozone. So let's put this up to the front and see whether or not

所以你說這個設備

we see an increase in the amount of ozone.

正在創造一種在城市中被視為霧霾的空氣

It's up over 80. So now I think

我相信是的

we're actually at the level of a smog alert.

對"淨化空氣"來說這有些荒謬

So you're saying that this device

你能聞到臭氧嗎? Yeah~ wow

is creating air that would be considered smog in a city?

這會給你帶來麻煩嗎？

I believe so yeah.

哦，這不會干擾我。我懂它 我會想離開實驗室或把它關掉

That is kind of ridiculous for something that's meant to purify the air. Can you smell

我在這能聞到什麼味道？

the ozone? -yeah -whoa

應該...... - 是的 甜蜜的氣味 - 是的 - 聞到了

Does it trouble you? Oh, it doesn't bother me. I know it and I

有點甜？ 是嗎？ 是的 - 我......

want to either leave the lab or turn it off.

很多人喜歡那味道，但如果你聞到它是不好的

What am i smelling for here?

所以也許我們應該關了它 在我們把自己搞窒息之前

should... -oh yeah the sweet smell -oh yeah -that smell a

所以，產生乾淨的負離子很有挑戰性的

little sweet? yeah? yeah -I uh...

但~它值得去努力嗎？這些研究並不一致。

A lot of people like that smell but if you smell that it's

沒有顯著差異 負離子對情緒和表現有益的證據無法被證明

not good. so perhaps we should shut this off before we asphyxiate ourselves.

在研究中所報告的顯著結果

So, generating clean negative ions is challenging but is it even worth

許多都有方法論問題

the effort? the research is inconsistent. No significant difference. Evidence for

一些參與者並沒有對他們正在接受的治療不知情

beneficial effects of negative ions on mood and performance could not be

當他們被隱瞞了 他們仍然可能透過微弱的臭氧味知道負離子的存在

demonstrated. Of the studies that report significant results,

大多數研究樣本量非常小

many have methodological problems in some participants weren't blinded to the

再加上他們對參與者調查了一定數量的測量

treatment they were receiving. When they were blinded they may still have known

導致產生至少一組顯著效果的機率 因為隨機機率而增加

when negative ions were present by the faint smell of ozone. Most of the studies

離子濃度通常是是在源頭測量的

have very small sample sizes. Plus they surveyed participants on a number

到受試者的距離並沒有沒有嚴格限制

of measures increasing the likelihood that at least one would show a

空氣的其他成分也沒規範

significant difference, just due to random chance. Ion levels were typically

所以無法保證參與者接收到了預期的離子濃度

measured at the source and the distance to subjects was not tightly controlled

2013年的一項綜合分析回顧了所有先前的人體離子研究，引用如下

nor were the other components of the air so there's no guarantee that

"正負離子對焦慮、心情、放鬆、睡眠與個人舒適度量 沒有一致性的影響效果"

participants were even receiving the expected levels of ions.

他們發現唯一的連結

A meta-analysis from 2013 reviewing all the prior human ion studies concluded there was quote "no

是在負離子空氣和較低抑鬱評分

consistent influence of positive or negative air ionization on anxiety mood

但作者警告說 "未來的研究需要評估這種關聯的生物學合理性"

relaxation sleep and personal comfort measures" the only link they found was

因為從根本上來說 離子有任何生物效果的想法是難以被取信的

between negative air ionization and lower depression scores, though the authors

思考一下，每cc的空氣有10^19個空氣分子

caution future research is needed to evaluate the biological plausibility of

所以即使有數以萬計的離子

this association.

卻是微不足道，甚至不到十億分之一 我們談的是千萬億分之一

Because fundamentally the idea that ions have any biological

並且沒有理由猜疑額外的電子無論如何會去做任何事情

effect is implausible.

我的意思是在你的日常生活中

Consider that in a cubic centimeter of air there are 10 to

你會不斷的在皮膚上充電，並在小小的瞬間放電

the 19 air molecules. So even with tens of thousands of ions the amount is