When is water safe to drink? - Mia Nacamulli

譯者: Szu-Wen Kung 審譯者: Marssi Draw

Take a look at the water in this glass.

觀察玻璃杯裡裝的水

Refreshing, hydrating, and invaluable to your survival.

清爽、水分飽滿 是人類生存的無價之寶

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

你如何得知杯子裡的水 沒有致病的有機體

and pollutants?

和汙染物？

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

世界上每十個人 就有一個無法確定

that their water is clean and safe to drink.

他們的飲用水是乾淨安全的

Why is that?

為什麼？

Inadequate sanitation,

貧乏的衛生設備

poor protection of drinking water sources,

飲用水資源的保護不足

and improper hygiene

及不合格的衛生

often lead to sewage and feces-contaminated water.

這些因素時常導致飲用水 受到汙水和糞便汙染

That's the ideal breeding ground for dangerous bacteria,

受到汙染的水源是 孕育危險細菌的溫床

viruses,

還包括病毒

and parasites.

與寄生蟲

And the effects of these pathogens are staggering.

這些病原體造成的影響極致深遠

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

不安全飲用水造成的腹瀉疾病

是導致全球五歲以下幼童 死亡的主因之一

around the world for children under five.

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

根據聯合國 2010 年的 一份報告顯示

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

每年死於水生細菌疾病的人數 比死於戰爭的還多

Proper treatment processes, though, can address these threats.

不過，正確的處理程序 能防治這類威脅

They usually have three parts:

處理程序通常有三個步驟：

sedimentation,

沉澱

filtration,

過濾

and disinfection.

消毒

Once water has been collected in a treatment facility,

一旦水集中至水處理廠

it's ready for cleaning.

便可接受淨化處理

The first step, sedimentation, just takes time.

首要步驟──沉澱，需花點時間

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

先將水靜置 讓較重的粒子沉到底部

Often, though, particles are just too small

但是粒子通常非常微小

to be removed by sedimentation alone

很難只用沉澱的方式去除

and need to be filtered.

因此需要過濾

Gravity pulls the water downward through layers of sand

重力把水往下吸引穿越過濾砂層

that catch leftover particles in their pores,

剩餘的粒子被濾砂層孔隙阻隔下來

prepping the water for its final treatment,

過濾的水能進行最後處理步驟

a dose of disinfectant.

加入消毒劑

Chemicals, primarily forms of chlorine and ozone,

成分為氯與臭氧的化學藥品

are mixed in to kill off any pathogens

摻入水中殺除病原體

and to disinfect pipes and storage systems.

同時消毒水管與儲水系統

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

氯能有效消滅水中有機體

but its use remains government-regulated

但氯的使用仍受限政府規定

because it has potentially harmful chemical byproducts.

因為氯含有 可能造成傷害的化學副產物

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

在消毒過程若含氯不均

it can trigger other chemical reactions.

會引發其他的化學反應

For example, levels of chlorine byproducts,

氯副產品

like trihalomethanes, could skyrocket, leading to pipe corrosion

像是三鹵甲烷可能激升 進而侵蝕水管

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

然後在飲用水裡釋出 鐵、銅還有鉛

Water contamination from these and other sources

如此一來 再加上其他原因的水汙染

including leaching,

包括土壤浸滲現象

chemical spills,

化學物質外洩

and runoffs,

河川逕流

has been linked to long-term health effects,

會對健康帶來長期影響

like cancer,

例如：癌症

cardiovascular and neurological diseases,

心血管與神經相關疾病

and miscarriage.

流產

Unfortunately, analyzing the exact risks

不幸的是，受化學汙染的水源

of chemically contaminated water is difficult.

所造成的明確風險 並不容易分析

So while it's clear that disinfectants make us safer

因此儘管消毒藥劑 確實能讓飲用水更安全

by removing disease-causing pathogens,

消除治病的病原體

experts have yet to determine the full scope

專家仍無法完全確定

of how the chemical cocktail in our drinking water

飲用水中的化學混合物

really impacts human health.

到底如何影響人類的健康

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

那麼該如何辨認 方便取得的水源

whether from a tap or otherwise,

無論是來自水龍頭 或其他來源

is drinkable?

可以安全飲用呢？

Firstly, too much turbidity,

首先，過於混濁的水

trace organic compounds,

水中含有機化合物

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

或具高密度的重金屬 例如砷、 鉻或鉛

mean that the water is unsuitable for consumption.

都意味著水不適合飲用

A lot of contaminants, like lead or arsenic,

許多汙染物，如鉛或砷

won't be obvious without tests,

沒有經過測試並不易察覺

but some clues, like cloudiness,

但其他的線索，如混濁

brown or yellow coloration,

水呈黃褐色

a foul odor,

臭味

or an excessive chlorine smell

或過量的氯氣味

can indicate the need to investigate further.

都顯示須採取進一步調查

Water testing kits can go a step further

可以用測試器具檢驗

and confirm the presence of many different contaminants and chemicals.

確認是否含有不同汙染物和化學物質

With many types of contamination,

對於不同型態的汙染

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

除了水處理廠外 日常生活也有處理飲用水的方式

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

日常生活水處理 其實已存在數千年

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

古埃及人用太陽熱能將水加熱 殺除有機汙染物

And in Ancient Greece, Hippocrates designed a bag

在古希臘醫生希波克拉底 設計一個袋子

that trapped bad tasting sediments from water.

能將難聞的沉積物從水裡濾出

Today, point-of-use processes usually involve ionization

現今日常生活飲用水處理 常用電離子

to lower mineral content.

減低水中的礦物質

They also use adsorption filtration,

也會使用吸濾式裝置

where a porous material called activated carbon

裝置上名為活性碳的孔隙材質

strains the water to remove contaminants and chemical byproducts.

會過濾水中的汙染物質 與化學副產物

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

儘管長遠來說 這並不是有效的方式

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

日常生活水處理器具 攜帶便利、好安裝又可調整

And in regions where large-scale systems are unavailable,

在沒有大型水處理系統的區域

or where water has been contaminated further along its journey,

或處理完畢的水 在運輸的過程中受到汙染

these systems can mean the difference between life and death.

日常水處理系統可救人一命

Clean water remains a precious and often scarce commodity.

淨水是珍貴時而稀有的產物

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

全球有近八億人口 仍無法正常取用乾淨的飲用水

The good news is that continued developments in water treatment,

好消息是水處理的持續發展

both on a large and small scale,

無論規模大小

can alleviate a lot of unsafe conditions.

能減低許多不安全的用水狀況

Implementing proper systems where they're needed

在需要之時 運用適當的水處理系統

and paying careful attention to the ones already in place

同時密切關注已在執行的系統

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

能保障人類最基本的需求之一