The Fog That Killed 12,000 People

[♪ INTRO] London is famously foggy. Sometimes that can mean a wistful stroll or
another excuse for a cuppa tea, but when fog mixes with the smoke and chemicals produced
by industry, it becomes something new: smog. And for a couple of centuries, London’s
smog could kill. Really bad smogs could kill a thousand people
in a few days, but no one did much about it until 1952, when a five-day smog in London
killed an estimated twelve thousand people. It was called The Great Smog of London, and
it helped wake up the country and the world to the dangers of unrestricted pollution. Fog is just a cloud that forms down here on
the ground, which by itself isn’t that bad; you might not be able to
see well when you’re driving, or you might not be able to
land your plane, but it’s nice. But clouds can act like sponges, forming around
and trapping whatever’s already in the air. This wasn’t a problem until
the 1200s, when a lot of London switched from wood to
coal for heating their homes. Burning coal creates soot and smoke,
which can irritate your lungs, and also creates poisons like
sulfur dioxide and carbon monoxide. Sulfur dioxide, which is a sulfur atom bonded
to two oxygen atoms, reacts with water to form sulfuric acid, which can harm your internal
organs, as you might imagine. And carbon monoxide, which is one carbon and
one oxygen, binds with the hemoglobin in your blood to stop oxygen from
getting around your body. So when London started burning coal, all the
smoke and chemicals mixed with the natural fog, and it became thicker
and darker as years passed. It wasn’t a health crisis at first, but people did complain that
the smoke smelled terrible. And this was back in the 1200s, when everything
smelled terrible already. But it was easier to keep burning coal than
to switch back to wood, so for centuries, they just accepted the occasional thick, dark,
smelly cloud hanging over the city. As you do. Things really got dangerous when the Industrial
Revolution happened in the 1700s. Because now, coal wasn’t just heating homes. It powered huge factories throughout the city,
and all that extra smoke and soot made the air in London’s fogs much darker. It became so common that a physician named
Harold Antoine Des Voeux invented the term “smog” to describe it. Really smoggy days completely blacked out
the center of the city, so that you couldn’t see more than a few meters ahead of you, even
in the middle of the day. The soot also irritated people’s lungs,
causing illnesses like bronchitis to become more common. Some people even suffocated from breathing
so much smoke or the poisons in the air. Individual smogs in 1873 and 1892 each killed
over a thousand humans and livestock. And we don’t even know how many people died
early from collecting soot in their lungs over the course of their lives. But coal kept London flourishing,
so nobody did anything to stop it. Then came The Great Smog. On December 5, 1952, a thick fog rolled in
and mixed with London’s dirty air, just like it did most winters. But this time, high-pressure
weather systems surrounded London and kept the cloud from moving on. So an especially dense, black smog stopped
on London for five miserable days. The smog was so thick that flights were grounded,
most public transportation was canceled, trains collided, and theaters
and movies stopped, because people couldn’t see
what they were watching. This is difficult to imagine, this was 1952,
not that long ago. An estimated four thousand people died in
those five awful days before the smog dissipated. A lot of them suffocated because their lungs
were inflamed from breathing in so much soot. And with sulfur dioxide from the burning coal
reacting with water vapor in the smog, Londoners also spent those five days
breathing air full of sulfuric acid. That and the smoke contributed to
respiratory and other health problems, which killed around another
eight thousand people in the following months. Ultimately, roughly one in a thousand Londoners
died because of The Great Smog. Some people argued afterward that the spike
in deaths was due to a flu epidemic, but scientists have investigated that in all sorts of ways,
and it’s really unlikely that the flu could have been anywhere near as devastating
as the smog itself. Four years later, Parliament finally passed
a Clean Air Act that dictated what kinds of fuels could
be burned within the city. It and other laws have helped rein in the
smog problem in London. But even today, London’s air pollution lowers
the life expectancy of a lot of people, and is indirectly linked to
tens of thousands of early deaths every year throughout the United Kingdom. Despite the Great Smog’s devastation,
it took a while for other industrial powerhouses to take the hint. New York City had a series of smogs in the
1960s that affected more than 16 million people, and black, soot-filled rain coated Boston
around the same time. But eventually, lawmakers
around the world stepped in. Starting in the 1970s, laws got serious about
limiting air pollution, forcing car companies to make more efficient engines, and factories
to produce fewer emissions. Because it turns out, turning air into poison,
is not a great idea. Thank you for watching this episode of
SciShow, you’re great. And a special thanks to all of our patrons
on Patreon for making it happen! If you’d like to help us make more episodes
like this, so that everybody can have them, regardless of whether they can pay,
you can go to, and if you just want to support us by watching,
please do that at [♪ OUTRO]

Comments 100

  • London is famously foggy. Except the majority of the time when it’s not

  • I thought it said The Frog That Killed 12,000 People

  • Persona 4 joke

  • "fish gotta swim and birds gotta fly,
    but they don't last long if they try"

  • China*huh what is this Clean Air you speak of?

  • no such thing as every thing smelt terrible or would do that or miserable, do, be any nmw and any b perfx

  • Aircraft pollution is out of control, Heathrow airport consumes 25+million litres of kerosene a day. London has six airports they consume so much kerosene it would be impossible to transport it by road, tyre particles and brake dust from landing and taking off is unforgivable, the lies and proper gander blaming the motorist is disgusting, no particulate filters on these dirty filthy giant oil burners, they cause so much pollution in the atmosphere not only are they giant kerosene heaters they are rainmakers they are turning sulphur dioxide into sulphuric acid that means you are flying in a sea of acid, jet engines are suffering from metal fatigue and corrosion the air in the aircraft cabins is toxic, pilots and cabin crew have one of the highest rates of cancer out of all occupations, rockets burnt the whole in the ozone layer and they blame the public on the ground you could not make it up, the co2 scam ,dry ice is co2 the earth's coolant,so much truth is being covered up, one point nine million domestic house old boilers use kerosene oil no particulate filters why not.

  • Dammit the children of atom are at it again

  • Look on the bright side, The Great Smog woke up the world because it killed so many people.

  • No one did much about it. People. We suck.

  • The White Whale made us think people died.

  • pretty sure this video sucks ass too

  • I thought it said frog


  • I swear to Christ I read this as "The Frog that killed 12,000 people", so when he started talking about "FOG", I was very disappointed…

  • fog =frog ,ha ha ha!

  • This is Chiang Mai today :/ looks like it will take 1000s of instant deaths before they do something about it.

  • "It turns out, turning the air into poison: not a good idea."

    Well, crumbs! There goes our entire economic model.

  • I like how they have quit using imperial measurements. Socialists.

  • Also known as the mist.

  • This kind of environmental problem is one of many massive problems if you don’t regulate corporations

  • At first I thought it said frog

  • If you think that was bad then try being stuck in my living room after my vegan wife eats her artificial chopped liver made from kidney beans and spices I can't pronounce. It isn't fog. It's a biblical creeping death. She says it's supposed to be healthy. …. I think she went to college with some lobbyists.

    Lobbyist logic = Well we can have our clean air and still buy our cheap junk because all the crap in the air is in China or India. It's technically not out problem.

    Smelly Vegan Wife Logic = Just go in another room. It doesn't matter that the entire apartment is almost 100% airtight and contaminated. If she doesn't hear me coughing and fighting dry heaves from the other side of the apartment, there isn't a problem.

    Darwin needs a resurrection.

  • I thought this was called The frog that killed 12,000 people

  • It wasn't just that they were burning coal. It was the type of coal. Post-war, solid, cleaner coal was used for industry, while homeowners were sold a cheaper coal that was basically dirt with coal in it, which produced a lot more airborne filth when burned.

  • Couldn't the flu have exacerbated an already bad situation?

  • New idea for protest at White House/congress coal grills+ fog machines + gaint fan = make them sit in the fruits of their own stupidity on climate change.

  • I remember that smog, it was, thick and smelly and it to follow you in doors. I was kept home from school so we're most of the others in my class.

  • You might include a few words about how population growth influenced the smog over the decades and centuries.. (nice shirt)

  • I never knew this happened…

  • At the end he said, "you're great" it really hit me. Ty hank

  • If you've ever been to London, even the "clean" air feels like you're breathing gravy. It's so thick and dirty and I got ill as soon as I went

  • People: gripe about air pollution.
    People: never say a word about China producing the most pollution in the world.

  • This is one of the reasons jack the ripper was so much more dangerous

  • im pro nuclear power in part because of hearing the story of the killer smog of 1952. please visit

  • What day, was Dec,5 1952

  • Human beings are stupid!

  • Green Day

  • "London's famously foggy." London isn't foggy at all. It was in the 1950s but what's next? "Alabama's buses are famously segregated"?

  • *Beijing and pretty much all of china “coughs” in the backround*…

  • Trump is quietly dismantling most of our modern clean air regulations and enforcement in the US. Just thought I'd throw that out there.

  • OMG, I read that as F R O G! Embarrassing

  • Their caber is made of Legos.

  • you should look into what killed hundredths of new yorkers in the 60s

  • Wait…trains collided? They relied on seeing each other to avoid collision?

  • The world is a much cleaner place and people are worried about global warming?

  • What about trumps " CLEAN COAL " ? ? ………………….

  • US firstly leave world environment protect group cause it will loss $$$, thus our earth pay for it !

  • The great smog of London
    The great fire of London
    The great stink of London
    The great of flood of London
    Next: The great ?____? of London


  • The Industrial Revolution started in the mid-1800s, not in the 1700s.

  • its cool, trump went ahead and got rid of all the regulations so we should be seeing this again soon.

  • 1:12 well i thought it should be Sulphurous acid, but i also forgot there is oxygen in the air

  • Hey China! Take freaking notes!

  • When I was a kid in UK in the 1950's smogs were common. People died every year. We used to call them pea soupers. My mother frequently had to wash clothes several times, also the washing line would be coated in soot. You knew it was a bad one when you couldn't see your own outstretched hand (that isn't a joke). You could really taste the smoke in the air. At that time every house had one or more coal fires and Britain was still a major manufacturing centre, and of course every factory had it's chimney.

  • Industrial Revolution in the 1700's?

  • Money kills directly this time.

  • Very informative… enjoyed watching.

  • If you watcht The Crown Season 2, It gets highlighted. its takes up the whole episode

  • Damn you really fooled me. I thought the title said the londons frog that killed 12,000 people. Damn Im waiting to hear about this thing….

  • So many ppl really don't realize how exceptionally blessed they are in all of human history to live in the modern west. Even today, there are areas in China where ppl deal with this same thing, for the most part: intense pollution. We in the west are very comfy and complacent, so much so that many of us have no clue how spectacularly great we have it in comparison with all of human history.

  • The smog actually created sulfurous acid, not sulfuric acid. But seeing as most viewers came for the killer frogs it doesn't really matter.

  • For some reason i read the frog that killed 12,000

  • I was a primary school pupil in London at the time. Mum stopped me going to school after she realised how bad it was getting. She used to stuff rags in any gaps that were letting in the awful stuff.

  • regulations save lives
    regulations are good

  • "I am fire…

    Oh sorry, wrong Smaug🐲

  • Once I ate baked beans with ham for two days and didn't see my cat for a further four days !!!

  • but but but Trump says "coal is clean" ! this is clearly fake news.
    jk. Trump and his robots are dangerous scum peasants

  • We used coal to warm our tents during winter in the military. When it is below zero, you don't care what you are burning to stay warm.

  • I grew up in London and remember the smogs. The smog was so thick you could literally not see your hand if you held it in front of your face. One time when I was 13 they let us out of school early because the smog was so bad. The driver of the bus I took to get home got lost. The conductor was walking in front of the bus with a torch to to guide the driver, but he ended up taking us up a driveway into a church yard, where he told us we have to all get off. Luckily I found my way home somehow passing people who looked like ghosts, trying to cover my mouth and nose with my pullover to filter the dirty sooty air.

  • i thought it said frog and kept waiting for the frog to be mentioned..for 3 minutes

  • Yep, in the 1970's, us Boomers made a slew of environmental laws, but of course it's our generation that gets blamed for everything these days. 🙄

  • I've been to England, from what I've seen and experiences I can say it's a shithole. Bad food, bad infrastructure, a lack of street lights, weak electricity, weak 4g internet and quality overall feels outdated. Like stale bread. Meanwhile it's overpriced as hell.

    I was thinking about taking the train from London to Glasgow. The price was 146 pounds…

    If I take the plane from Zaventem to Glasgow it costs me a mere 60 euro. That's about 50 pounds.

    I haven't been to Wales so I can't judge that part. But my guess is that whole south england including Wales is an overpriced shithole. Someday I'll visit Schotland and the Irelands.

    For now, the UK sucks balls.

  • London and New York both used to be so smoky and sooty.

  • NO!
    SO2 reacts with water to form sulfurous acid not sulfuric acid, you would need to oxidize the sulfur to its plus 6 oxidation state to make sulfuric acid and elemental oxygen cannot do this alone.

  • I beat my wife while watching this

  • Thought this said the frog… Informed, but disappointed.

  • This makes no sense as wood is itself a nasty and dirty burning fuel and high ranks of thermal coal burning cleaner than wood.

  • When pollution is free we all lose. Help Congress put a price on climate pollution while protecting household purchasing power:

  • So your saying Trump reliving the coal restrictions are a good thing and lowering restrictions on the EPA might help people. Lol

  • I wonder how the fossil fuel lobby pushed against these changes.

  • And we’re still digging coal. How moronic.

  • the smog didn't do it, the poisons did, cause sometimes you have to learn lessons the hard way. or did the Illuminate just put it in the air, YEAH FIRST CHEM TRAILS, Congratulations. we needed less limies anyway.. Thanks Obama!

  • I thought this was a video about the hazards of vaping.

  • I thought the title said “The Frog That Killed 12,000 People” and I was thinking, oh! Like another mini plague

  • Sometimes you need a 12,000 person die off to influence your smoggy ways.

  • Things always are the worst when in a western country. Poor westerners. You always have it so bad compared to the rest of the world. And you never cause it your self or to others…

  • I swear it said frog 🐸… Not fog 🌫️! I was like "holy crap! Frogs are killing people in England?!" Lol

  • So is this a real SCP?

  • Only clicked bc I thought a single frog killed 12,000

  • Let's allow coal burning in California!

  • Elect some republicans. They're obsessed with repeating the mistakes of the past.

  • technically Oxygen is a poison it just works very very slowly

  • I thought that said frog and I was really excited 💔

  • When syncrude farted out a big green cloud that made a bunch of workers sick it was called the ploom of doom.

  • I read the title wrong and was waiting to see what one poor little frog did

  • Hmmm.. So this is why they have that strange accent.

  • Another scary event similar to this was a gigantic Co2 pocket in lake Nyos bursed and caused the Co2 to disperse across the land into the nerby towns around it. It was basicly an invisible cloud of death that killed over a thousand people.

  • The smog was worse than it needed to be because the Labour government of the time had decided to export the good quality coal and leave the poorer quality coal to be burned in the fireplaces of peoples homes and in the railway engines of the time. I was there in suburbs of London in 1952 but only a couple of years old. I remember the last London smogs in the early 1960's. After this point in time the clean air acts had been passed and all the houses had had gas fires fitted in their fireplaces. No domestic coal burning allowed only smokeless fuel could be used in any remaining fireplaces. Despite what some people say the air is on hell of a lot cleaner in 2019 than it was in 1960. The problem is the exemptions that were made for pollution controls, Diesel Trains that were exempt until the 2000's, London taxis that are exempt from the Low emission charge and the people who burn wood chippings in their Aga's which is illegal. Private cars etc have all had particulate filters fitted along with catalytic converters. Motor bikes emit as much pollution as a full sized car but do not seem to have particulate filters or catalytic converters. Is the excuse there are not very many of them?

  • Same thing with global warming. Need to wait till some cities are permanently destroyed before any government would do anything about it.

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