When is water safe to drink? – Mia Nacamulli

By Brian Lemay 100 comments

Take a look at the water in this glass. Refreshing, hydrating, and invaluable
to your survival. Before you take a sip, though, how do you know that the water inside
is free from disease-causing organisms and pollutants? One out of ten people in the world
can’t actually be sure that their water is clean
and safe to drink. Why is that? Inadequate sanitation, poor protection of drinking water sources, and improper hygiene often lead to sewage
and feces-contaminated water. That’s the ideal breeding ground
for dangerous bacteria, viruses, and parasites. And the effects of these pathogens
are staggering. Diarrheal disease from unsafe water is one
of the leading causes of death around the world for children under five. And according to a U.N. report from 2010, microbial water-borne illnesses killed
more people per year than war. Proper treatment processes, though,
can address these threats. They usually have three parts: sedimentation, filtration, and disinfection. Once water has been collected
in a treatment facility, it’s ready for cleaning. The first step, sedimentation,
just takes time. The water sits undisturbed, allowing
heavier particles to sink to the bottom. Often, though, particles
are just too small to be removed by sedimentation alone and need to be filtered. Gravity pulls the water downward through
layers of sand that catch leftover particles
in their pores, prepping the water
for its final treatment, a dose of disinfectant. Chemicals, primarily forms
of chlorine and ozone, are mixed in to kill off any pathogens and to disinfect pipes
and storage systems. Chlorine is highly effective in destroying
water’s living organisms, but its use remains government-regulated because it has potentially harmful
chemical byproducts. And if an imbalance of chlorine occurs
during the disinfection process, it can trigger other chemical reactions. For example,
levels of chlorine byproducts, like trihalomethanes, could skyrocket,
leading to pipe corrosion and the release of iron, copper,
and lead into drinking water. Water contamination from these
and other sources including leaching, chemical spills, and runoffs, has been linked
to long-term health effects, like cancer, cardiovascular and neurological diseases, and miscarriage. Unfortunately, analyzing the exact risks of chemically contaminated
water is difficult. So while it’s clear that disinfectants
make us safer by removing disease-causing pathogens, experts have yet
to determine the full scope of how the chemical cocktail
in our drinking water really impacts human health. So how can you tell whether the water
you have access to, whether from a tap or otherwise, is drinkable? Firstly, too much turbidity, trace organic compounds, or high-density heavy metals like arsenic,
chromium, or lead, mean that the water
is unsuitable for consumption. A lot of contaminants,
like lead or arsenic, won’t be obvious without tests, but some clues, like cloudiness, brown or yellow coloration, a foul odor, or an excessive chlorine smell can indicate the need
to investigate further. Water testing kits can go a step further and confirm the presence of many different
contaminants and chemicals. With many types of contamination, there are ways of treating water where
it’s used instead of close to its source. Point-of-use treatment has actually
been around for thousands of years. Ancient Egyptians boiled away many
organic contaminants with the sun’s heat. And in Ancient Greece, Hippocrates
designed a bag that trapped bad tasting
sediments from water. Today, point-of-use processes usually
involve ionization to lower mineral content. They also use adsorption filtration, where a porous material
called activated carbon strains the water to remove contaminants
and chemical byproducts. While it’s not always an effective
long-term solution, point-of-use treatment is portable,
easy to install, and adaptable. And in regions where large-scale
systems are unavailable, or where water has been contaminated
further along its journey, these systems can mean the difference
between life and death. Clean water remains a precious
and often scarce commodity. There are nearly 800 million of us who
still don’t have regular access to it. The good news is that continued
developments in water treatment, both on a large and small scale, can alleviate a lot of unsafe conditions. Implementing proper systems where
they’re needed and paying careful attention
to the ones already in place will fulfill one of the most basic
of our human needs.



Sep 9, 2017, 2:50 am Reply

Yo at 0:43 there's fidget spinner viruses no wonder why it was so popular

Iris J.

Sep 9, 2017, 3:02 am Reply

I remember I drunk some water and the container it was in must've been contaminated I was back as forth out the bathroom for hrs and days after day 3 I went to the doctors and they said I had "Travel Diaherra" I had it for about 3-6 days when I started drinking water at home I felt better it was definitely from the water at the restaurant I ate at and no it wasn't food poison my moral is please make sure the water you are drinking is safe I live in the USA and it's uncommon here but when I went to Singapore all bets were off and I was running to the bathroom didn't even finish my food I thought I might've had a stomach bug but when I landed back at home there I was running to the bathroom again … Good thing I had gotten it a day before I was leaving


Sep 9, 2017, 6:22 pm Reply

thanks for making me paranoid about stuff im drinking


Sep 9, 2017, 3:24 pm Reply



Sep 9, 2017, 3:24 pm Reply



Sep 9, 2017, 3:24 pm Reply



Sep 9, 2017, 3:24 pm Reply



Sep 9, 2017, 5:04 pm Reply

Water is so precious, it comes and a heaving price of 1p > a liter.

Narkyssa the dandidoo

Sep 9, 2017, 4:25 pm Reply

I did my homework wrong

cosmic –

Sep 9, 2017, 7:42 pm Reply

the PointOfView system thing would be so helpful for those in flint, michigan and drier parts of the world

SCP Foundation

Oct 10, 2017, 3:32 am Reply

I see blue fidget spinners

Rafa Rodhes

Oct 10, 2017, 1:01 am Reply

We take so many things for granted 🙁

Jack Fu

Oct 10, 2017, 12:44 pm Reply

My Wordbook:
Byproduct 副产品
Consumption 消费
Hydrating 保湿
Organisms 有机体
Pollutants 污染物
Inadequate 不充分的,不恰当的
Sanitation 环境卫生
Hygiene 卫生
Parasites 寄生虫
Pathogens 病原体
Diarrheal 腹泻
Sedimentation 沉淀
Filtration 过滤
Disinfection 消毒
Chlorine 氯
Trihalomethanes 三卤甲烷
Contamination 杂质
Leaching 浸出
Cardiovascular 心血管
Neurological 神经病学的
Miscarriage 流产,失败
Arsenic 砷,砒霜
Chromium 铬
Ionization 电离
Carbon 碳
Runoff 决赛,径流


Oct 10, 2017, 7:31 am Reply

My teacher put tap water in a fish bowl and they died

Vincent Labrecque

Oct 10, 2017, 6:52 pm Reply

Wow, amazing animation!

Carlos DelaCruz

Oct 10, 2017, 11:03 am Reply

This narrator's voice is so soft i could barely hear him in a quitet room

Animation & Postproduction

Oct 10, 2017, 7:26 pm Reply

Any water filter/purifier (brand) recommendation?


Oct 10, 2017, 8:38 pm Reply

"kills more than war" even suicide may kill more than war…. Crime kills more than war, we're a peaceful world if you only take war casualties as the big deal. Stop trying to create drama.

The Dirtiest Rebel Around

Oct 10, 2017, 10:01 pm Reply

Why don't we also boil the water?

prashant bisht

Nov 11, 2017, 6:15 pm Reply

Q:When is water safe to drink?
A: when diluted with WHISKY….

lino feet

Nov 11, 2017, 4:44 am Reply

god now im scared to drink water

Maria Diwata Sabolboro

Nov 11, 2017, 2:06 pm Reply


usdusi nsusia

Nov 11, 2017, 7:56 am Reply

Firstly, use a water pureififer
Secondly, boil it
Thirdly, leave it to cool
Fourthly, enjoy

mickey dicky

Nov 11, 2017, 7:04 pm Reply

if its water.

Evans Castro

Nov 11, 2017, 7:53 pm Reply

please answer when to best drink ?!!!! please be specific kyahhhh!!


Dec 12, 2017, 5:15 am Reply

Infinite water bottle is amazing

Tim Namhay

Dec 12, 2017, 12:16 am Reply

Now I'm scared to drink water

Hans Michaelsen

Dec 12, 2017, 10:38 pm Reply


Diana Sanchez

Dec 12, 2017, 12:55 am Reply

Thank you you made me spit the water on My brothers shirt


Dec 12, 2017, 10:30 pm Reply

When it’s in ur sink

-14 subscribers with no videos

Dec 12, 2017, 1:45 am Reply

la has like 10 things

Kirk Preston

Dec 12, 2017, 1:00 am Reply

Your videos are very helpful. I show them to my students to support their learning in my classroom

April Yoon And TaisupYoon

Dec 12, 2017, 2:25 am Reply

Can u do my question ted ed? How do wild animals get domesticated? – April Yoon

Manan Sood

Dec 12, 2017, 11:10 am Reply

how about boiling the water


Dec 12, 2017, 11:05 am Reply

Let your enemy's drink it

Shigemi Notoge

Dec 12, 2017, 4:18 pm Reply

: did I just watch a 5 minute and 23 second advertisement for a water filtration company?

C_the_survivor Poll

Dec 12, 2017, 12:44 am Reply

There was an ad at the beginning about Bose headphones and also TED and I’m using Bose headphone and watching a TED. Video ??

Carlos Torres

Dec 12, 2017, 6:00 pm Reply

So your saying that we cant hardly tell anything wrong but only tests can??


Dec 12, 2017, 12:43 am Reply

is the near future, we will use graphene to filter out water
its very effective

Amruta Koshe

Dec 12, 2017, 5:41 am Reply

Am I the only one who interpreted the title in a different way? I thought the video was gonna be about when we should drink water, like in the morning, before/after a meal,etc…. XD

Christopher Castro

Jan 1, 2018, 5:34 pm Reply

im in class whats uo faaam where the girls at

crystal deer

Feb 2, 2018, 11:23 am Reply

yeah i dont drink water from faucets.

Jason Chen

Feb 2, 2018, 7:34 pm Reply

When i was 5 I didn’t get sick ? from water ? and if we have a nuclear war it will do more damage than water

Renters GT

Mar 3, 2018, 6:16 pm Reply


Renters GT

Mar 3, 2018, 6:17 pm Reply

wnna do me?

Adeline Renee Dayot Corpuz

Mar 3, 2018, 1:46 pm Reply

Hm, I drink Mtn Dew more than water

I’m still breathing

Mar 3, 2018, 4:20 am Reply

This is why I'm never drinking water again ???

joji tingz

Mar 3, 2018, 8:58 am Reply

i just realized that the artist here used watercolor for an animation about water safety. genius.


Mar 3, 2018, 1:31 pm Reply



Apr 4, 2018, 9:13 pm Reply

How about using chlorine dioxide instead of chlorine?


Apr 4, 2018, 12:44 am Reply

So, if chlorine has so many potential byproducts, why don't we just boil the water to kill germs?

R.K. Swain

May 5, 2018, 12:12 pm Reply

Make a video about drink water while standing

Nicole Yoo

May 5, 2018, 4:14 am Reply

Lol I got an ad for this video about knowing how clean ur water is for real.

Megan Myhre

May 5, 2018, 5:44 am Reply

Another good idea would be to I dunno let our immune system do its damn job! Sure limit high deadly infections and maybe reduce the number but humans somehow didn't go extinct before soap was invented and I just can't think of why (sarcasm). We reap what we sow too. Pollution is hard to undo cough cough mining

cupcakemirin456 Monteiro

May 5, 2018, 5:01 pm Reply

If water is essential to our survival, why is it this dangerous to drink?

Jay747 Aviation

May 5, 2018, 1:39 am Reply

Lol ? i got a water purifier ad before this


May 5, 2018, 2:32 pm Reply

TED you are the best in the world thank you so much

Joselyn Vifquain

May 5, 2018, 1:33 am Reply

Who else got a water filter ad before this vid?
Just me…okay I’ll leave now

Shadow #WoF

May 5, 2018, 12:46 am Reply

Im drinking a bottle of water as im watching this

Phantom 309

May 5, 2018, 7:36 pm Reply

This is why i drink soda

Pastel_ M598

Jun 6, 2018, 9:35 pm Reply

My family don't directly drink tap water, we put it in a container that filters the water, and then we put it in water bottles for us to drink it. (Note: We don't have glasses)

Naa Okailey

Jul 7, 2018, 9:16 am Reply

Anybody here for C14?


Jul 7, 2018, 8:31 pm Reply

The water She/He drinks turns She/He into water


Jul 7, 2018, 7:05 pm Reply

0:32 that’s how cholera was spread in mideveil Britain


Aug 8, 2018, 9:59 am Reply

If we are lost in the forest and you don't have any water… "WHAT WILL YOU DO?" – Find the lake or the river and drink? I think we must do it if you don't have any water!

Henry Tetreault

Sep 9, 2018, 2:36 am Reply

I’ll have to lookup ancient Egyptian and Hypocrates techniques of water purification.

Radmehr Sasani ❶

Sep 9, 2018, 6:17 pm Reply

Add me as a friend on YouTube https://youtu.be/addme/9gctWqz2HspAk3v7Eqjo5UsL0rKemQ

Galaxy Animations

Sep 9, 2018, 3:01 am Reply

The next pewdiepie

Moonlight Animations

Oct 10, 2018, 12:10 pm Reply

Boil the damn water


Oct 10, 2018, 4:36 am Reply

wow fidget spinners in the water how creative

tueninh duong

Oct 10, 2018, 7:15 am Reply

Please keep Clean water to use

Chaos Churros

Oct 10, 2018, 10:51 am Reply

But can I drink rain water

Omar ElSherif

Nov 11, 2018, 1:59 am Reply

what about expired water is it safe to drink?

Jealous Pig

Dec 12, 2018, 12:48 pm Reply

When I pee in it…

Minh P.Quang

Dec 12, 2018, 1:54 pm Reply

Hydric acid in water is so dangerous, be careful from it!

DIYAZ – Gaming

Dec 12, 2018, 4:41 am Reply

Is this how you bold?

Nice, looks like I got it

John Han

Jan 1, 2019, 9:23 pm Reply

School water fountain water is never safe to drink

1 2

Jan 1, 2019, 12:00 pm Reply

Our drinking water is not TAP WATER we use MINERAL WATER in our country which is safer

Trungkien Le

Feb 2, 2019, 8:24 am Reply

Besides these things, there can be T-virus


Feb 2, 2019, 2:56 am Reply

When it looks clean

S Snow

Feb 2, 2019, 11:49 pm Reply

You can't smell or see lead in your drinking water. However, you can test to see if it is present and at a low cost: www.watersafetestkits.com


Feb 2, 2019, 11:11 pm Reply

We should better help all poor country to help the people from suffering!

Katy Out n About

Feb 2, 2019, 7:22 am Reply

The water situation in Karachi is a worth-while read

Manjot Singh

Mar 3, 2019, 12:50 pm Reply

Eat ice
Its better than water and is refreshing

Joseph Manning

Mar 3, 2019, 7:49 pm Reply



Mar 3, 2019, 5:24 pm Reply

I don't drink by tap water, i use aquagaurd(water filter)

Mer Tibang

Mar 3, 2019, 11:11 am Reply

Hey there is healthy and there are not healthy but water is very healthy dude

[Insert Name]

Jun 6, 2019, 10:43 pm Reply

Phew, at least my mother boils the water and puts it in a safe container so all the pathogens are dead.

Vatican Scientist

Jun 6, 2019, 5:55 am Reply

Who else got thirsty after watching this?

Hays Pure Water For All

Jun 6, 2019, 9:29 pm Reply

Assume ALL water is not safe to drink until a coliform bacteria test has proven that whatever treatment process was used works! We at hays Pure Water treat millions of the poorest peoples water in 50 countries for decades using a hand held devise, sun and salt. Results are life changing, people go to work, kids go to school communities are vibrant and hospitals are almost empty. Find out more at hayspurewater.com.


Jul 7, 2019, 2:09 pm Reply

I know it’s safe cause I have a filter in my refrigerator


Aug 8, 2019, 11:28 pm Reply

Reads title

It’s unsafe to drink?

Son of Ode

Oct 10, 2019, 8:14 am Reply

Cook em.

امل امل

Nov 11, 2019, 2:21 pm Reply



Nov 11, 2019, 9:45 pm Reply

3:11 Remember everyone, if you see letters in your water, don't drink it!

Rashmita Senapati

Nov 11, 2019, 3:02 pm Reply

You are ģgggggggggggggrrrrrrrrrrrreeeeeeeeeeaaaaaaaaaaatttttyyy

sarang pahwa

Nov 11, 2019, 10:23 am Reply

Now I'm very much grateful that I've easy access to clean water?

Tannei Sarker

Dec 12, 2019, 4:36 am Reply

Thanks. Now I’m scared of my tap

Mr Lime

Dec 12, 2019, 12:45 pm Reply

Can't I just boil the water before drinking it to kill the germs?

Huy Trần Nhật

Dec 12, 2019, 5:03 am Reply

Can I know the name of background?

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