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  • [♩INTRO]

  • In the mid-1800s, factories began mass-producing matches.

  • Lots of them were hugely successful, and pretty soon,

  • they were selling millions of matchboxes a year.

  • And then the factory workersmany of whom were young womenstarted dying.

  • The symptoms would often start with a toothache and jaw pain

  • and then progress to tissue death.

  • In some cases, the condition was fatal.

  • Doctors eventually realized the problem was the kind of phosphorus

  • used in the matches at the time, so they called the condition phossy jaw.

  • But it still took decades and governmental crack-downs for companies to switch over

  • to another, safer type of phosphorus.

  • These days, phossy jaw would be little more than a relic of history,

  • if it weren't for one thing: It's also a side effect in modern medicine.

  • The English chemist John Walker is frequently credited with inventing

  • the type of friction matches we would recognize, back in the 1820s.

  • The main ingredients in his match heads were potassium chlorate

  • and antimony sulfide, which ignited from the heat of friction

  • if you rubbed the match on sandpaper.

  • There were some problems with these matches, though.

  • Sometimes they didn't light at all

  • and because you had to really scrape them to get the flame going, sometimes,

  • the head of the match just flew off and there became a tiny little fireball.

  • Which was understandably concerning.

  • Everything was flammable back then!

  • Within ten years, though, a bunch of people independently

  • came up with an idea for a better match.

  • They replaced the antimony sulfide with white phosphorus

  • one of the few different forms pure phosphorus can take

  • which took much less heat to ignite and was therefore much more reliable.

  • Soon, phosphorus match factories went into production all over the world.

  • And then the case reports started rolling in:

  • Factory workers were developing what would soon become known as phossy jaw.

  • The disease led to severe infections and caused the patient's bones to rot

  • often starting with the jawbone.

  • At the time, the only real treatment was to remove any damaged bones

  • and hope the infection wouldn't spread to the brain and turn fatal.

  • It became clear that the problem had something to do with the white phosphorus

  • they were working with.

  • Around one in ten workers on the factory floor developed phossy jaw

  • within five years of exposure, while the office workers were unaffected.

  • And it turns out white phosphorus is really reactive,

  • so it was combining with water vapor and carbon dioxide in the workers' breath

  • as well as amino acids in their saliva to create bisphosphonates.

  • These compounds suppress a type of bone cell called osteoclasts,

  • whose job is to break down and reabsorb regular bone tissue.

  • So essentially, bisphosphonates keep bones from replenishing themselves.

  • And that lack of replenishment is more of a problem for bones

  • with fast cell turnover rateslike the jawbone.

  • So in the presence of bisphosphonates, the jawbone would start to die.

  • And about 20% of the time, so would the patient.

  • Lower class workers around the world knew this was happening.

  • So did their doctors, and at least some of the general public.

  • I mean, Charles Dickens was writing about it in 1852.

  • But factories in the mid-19th century weren't exactly known

  • for their concern about factory workers.

  • And for decades, very little changed.

  • Then, in 1888, a match factory in London took things a step too far

  • and proved themselves to be especially terrible.

  • That spurred a local socialist and activist, Annie Besant,

  • to write about the horrible conditions in the factory

  • which, in addition to the health risk, also included long hours,

  • low pay, and fines if a worker so much as dropped a match.

  • In response, the owners of the factory tried to get the workers

  • to sign a statement saying they were perfectly happy with life there.

  • They refused, and when one of the workers was fired, all fourteen hundred of them

  • went on what would become known as the Matchstick Girls' Strike.

  • The strike finally called the world's attention to the phossy jaw problem.

  • And it just so happened there was another, safer way to make matches,

  • which was discovered around 1850.

  • The key is red phosphorus, another form of pure phosphorus.

  • Its atoms are arranged differently, which means it doesn't react chemically

  • the same way white phosphorus does

  • so it doesn't cause phossy jaw and therefore isn't dangerous to factory workers.

  • There is another benefit to red phosphorus, too:

  • You can use it to make safety matches

  • these matches only light if you strike them on the box.

  • In safety matches, the match itself doesn't actually contain any phosphorus.

  • Instead, the box is coated in red phosphorus and powdered glass,

  • while the match head's ingredient is usually potassium chlorate.

  • When you strike the match on the box, the friction with the powdered glass

  • generates enough heat to turn a tiny amount of the red phosphorus

  • into white phosphorus.

  • Then, this miniscule amount of white phosphorus ignites

  • those are the sparks you see as you strike the match

  • and the heat from that ignites the potassium chlorate on the match head.

  • And, finally, you get the flame.

  • Now, despite all this, it took a long time for red phosphorus matches

  • to go mainstream.

  • That's partly because it wasn't until 1906 that multiple countries came together

  • and signed a treaty banning white phosphorus matches.

  • Even then, the US was not among the signatories

  • so they kept making them for another twenty-five years.

  • Now, there are also other industries that use white phosphorus,

  • so changing over matches didn't completely eliminate its use.

  • Still, as match factories switched to red phosphorus,

  • the number of new cases of phossy jaw dropped dramatically.

  • At least, until around 2003.

  • See, in the 1990s, doctors started prescribing bisphosphonates

  • to treat certain types of bone disease

  • like, metastatic cancers that spread to the bone from other parts of the body.

  • Researchers still aren't totally sure how bisphosphonates help,

  • but they think it has something to do with keeping healthy bone cells

  • from being replaced by damaged ones.

  • But then, the jawbones of some of the patients started dying.

  • Scientists quickly made the connection to the phossy jaw

  • of the late nineteenth century,

  • and realized the tissue death was a side effect of the medication.

  • So, they decided to call this new disease bis-phossy jaw.

  • And it is still a thing.

  • For a lot of patients, the benefits of bisphosphonates outweigh the risk

  • of developing bis-phossy jaw, so they're still being prescribed.

  • And thanks in part to the match factory workers way back when,

  • we know a lot about what symptoms to look out for when someone is at risk.

  • It may have taken a long time for the world to recognize the extent of the exploitation

  • of those factory workers, but over 130 years later,

  • the legacy of the matchstick girls lives on.

  • Thanks for watching this episode of SciShow!

  • If you enjoyed this stroll through science history,

  • you might also like our episode on that time the US government poisoned booze.

  • And maybe consider clicking on that subscribe button

  • We put out a new video every day,

  • so you can count on us to feed your hunger for science knowledge.

  • [♩OUTRO]

[♩INTRO]

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マッチの暗黒歴史 (The Dark History of Matches)

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    林宜悉 に公開 2021 年 01 月 14 日
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