Refreshing, hydrating, and invaluable to your survival.

既乾淨、滋潤又珍貴，能維持人類基本生存

Before you take a sip, though,

不過，在你啜飲之前，

how do you know that the water inside is free from disease-causing organisms

你怎麼判定水裡面有沒有有害的有機物質

and pollutants?

或者是汙染物

One out of ten people in the world can't actually be sure

世界上有十分之一的人口，沒有辦法完全確保

that their water is clean and safe to drink.

他們的飲用水夠純淨和安全

Why is that?

為什麼會這樣呢？

Inadequate sanitation,

公共衛生設施不足、

poor protection of drinking water sources,

並未妥善保護飲用水的水源、

and improper hygiene

抑或不當的衛生觀念

often lead to sewage and feces-contaminated water

都有可能導致水源混濁或是遭受汙染

That's the ideal breeding ground for dangerous bacteria,

遭受汙染後，就成了孳生細菌、

viruses,

病毒、

and parasites.

和寄生蟲的溫床

And the effects of these pathogens are staggering.

這些病原體的影響非常長遠

Diarrheal disease from unsafe water is one of the leading causes of death

因不乾淨的水源而造成的致命疾病 - 痢疾

around the world for children under five.

是世界上許多五歲以下孩童的主要死因

And according to a U.N. report from 2010,

根據聯合國在2010年的報告

microbial water-borne illnesses killed more people per year than war.

每年飲用含有微生物的水而死亡的人口，比戰爭死亡的人多很多

Proper treatment processes, though, can address these threats.

然而，其實只要水源經過適當處理，死亡風險就會大幅降低

They usually have three parts:

常見的治療方法有三種：

sedimentation,

沉澱、

filtration,

過濾、

and disinfection.

還有消毒

Once water has been collected in a treatment facility,

只要水資源一進入淨水設備，

it's ready for cleaning.

就代表可以淨化它們了

The first step, sedimentation, just takes time.

首先，沉澱所需要的就是時間

The water sits undisturbed, allowing heavier particles to sink to the bottom.

水源不能受到擾動，才能讓較重的粒子沉到底部

Often, though, particles are just too small

不過粒子通常過於細小

to be removed by sedimentation alone

沒辦法只透過沉澱去除

and need to be filtered.

所以接下來就需要過濾

Gravity pulls the water downward through layers of sand

重力協助水通過層層砂石

that catch leftover particles in their pores,

過濾殘餘的粒子

prepping the water for its final treatment,

讓水準備進入淨化的最後一個步驟，

a dose of disinfectant.

徹底殺菌

Chemicals, primarily forms of chlorine and ozone,

化學藥劑，大多由氯和臭氧組成，

are mixed in to kill off any pathogens

經混合後用以殺死病原體

and to disinfect pipes and storage systems.

同時為水管和儲水系統消毒

Chlorine is highly effective in destroying water's living organisms,

氯可以有效消滅水中的有機物質，

but its use remains government-regulated

但是氯的使用仍受到政府規範

because it has potentially harmful chemical byproducts.

因為它含有潛在的有害化學物質

And if an imbalance of chlorine occurs during the disinfection process,

因此，假設氯含量在消毒的過程中失衡，

it can trigger other chemical reactions.

就會引起其他的化學作用

For example, levels of chlorine byproducts,

舉例來說，氯的副產品之一，

like trihalomethanes, could skyrocket, leading to pipe corrosion

像是三鹵甲烷，可能會突然著火，導致水管腐蝕

and the release of iron, copper, and lead into drinking water.

並讓銅鐵等金屬物質跑到飲用水中

Water contamination from these and other sources

上述為水污染的原因之一，另外

including leaching,

滲漏、

chemical spills,

化學物流出、

and runoffs,

或是逕流，

has been linked to long-term health effects,

也會對健康帶來長期的危害

like cancer,

像是癌症、

cardiovascular and neurological diseases,

心血管和神經相關的病症、

and miscarriage.

或是流產

Unfortunately, analyzing the exact risks

令人遺憾的是，實際預測

of chemically contaminated water is difficult.

化學汙染水的風險很困難

So while it's clear that disinfectants make us safer

所以儘管我們知道飲用水在經消毒後可以讓人喝得更安心，

by removing disease-causing pathogens,

因為病原體會被去除，

experts have yet to determine the full scope

但專家尚未有精確的儀器可以測量

of how the chemical cocktail in our drinking water

飲用水中的雞尾酒化學物質

really impacts human health.

是否真的影響人類健康

So how can you tell whether the water you have access to,

那麼應該如何判別你飲用的水，

whether from a tap or otherwise,

不管是來自水龍頭或是其他水源，

is drinkable?

都是可以飲用的？

Firstly, too much turbidity,

首先，水質混濁的時候

trace organic compounds,

可以看見有機化合物的痕跡，

or high-density heavy metals like arsenic, chromium, or lead,

而密度較大的重金屬像是砷、鉻或鉛也可以用肉眼看出

mean that the water is unsuitable for consumption.

看見這些浮動的化合物，代表水源不適合飲用

A lot of contaminants, like lead or arsenic,

很多像是鉛或是砷的汙染物

won't be obvious without tests,

未經檢驗不易察覺

but some clues, like cloudiness,

不過還是有線索可循，像是色澤朦朧陰暗、

brown or yellow coloration,

帶點棕黃的顏色、

a foul odor,

散發惡臭味、

or an excessive chlorine smell

或是有刺鼻的氯味，

can indicate the need to investigate further.

這類的水源就要接受進一步的檢驗

Water testing kits can go a step further

水源測試可以更詳細檢查

and confirm the presence of many different contaminants and chemicals.

並且確認水質裡含有什麼污染物和化合物

With many types of contamination,

如果水中含有多種汙染物

there are ways of treating water where it's used instead of close to its source.

應該要先從使用地區開始著手處理，而非從水源下手

Point-of-use treatment has actually been around for thousands of years.

點狀淨水已經運作好幾千年

Ancient Egyptians boiled away many organic contaminants with the sun's heat.

古埃及人運用太陽的溫度將水煮沸，以去除有機汙染物

And in Ancient Greece, Hippocrates designed a bag

古希臘名醫希波克拉底設計了一個袋子

that trapped bad tasting sediments from water.

可以過濾水中的沉積物

Today, point-of-use processes usually involve ionization

現今點狀處理的技術包含電離，

to lower mineral content.

好減少金屬

They also use adsorption filtration,

他們也會使用抽離過濾，

where a porous material called activated carbon

運用滲透性材質 ─ 活性碳

strains the water to remove contaminants and chemical byproducts.

擠出水源，來移除汙染物和化學副產品

While it's not always an effective long-term solution,

儘管這終究非長久之計，

point-of-use treatment is portable, easy to install, and adaptable.

點狀淨化方便攜帶，裝設簡易，可塑性高

And in regions where large-scale systems are unavailable,

在大型系統難以設置的地區，

or where water has been contaminated further along its journey,

或是水源在運送過程中受到汙染時，

these systems can mean the difference between life and death.

點狀設施就可以派上用場拯救生命

Clean water remains a precious and often scarce commodity.

乾淨的水資源非常珍貴稀有，卻是日常所需

There are nearly 800 million of us who still don't have regular access to it.

世界上卻有大約 8 億人口仍然難以觸及乾淨水源

The good news is that continued developments in water treatment,

好消息是，隨著水質淨化的方法日新月異，

both on a large and small scale,

不管大規模或小規模的地區

can alleviate a lot of unsafe conditions.

都有機會解除汙水警報

Implementing proper systems where they're needed

在需要之處裝設合宜的處理系統

and paying careful attention to the ones already in place

同時定期關注與檢驗已設置的系統

will fulfill one of the most basic of our human needs.

可以完成人類最基本的需求之一