How Engineers Move Medicine Around the World

Thanks to Emerson for supporting this episode
of SciShow. To learn more, visit [♪ INTRO] Thanks to modern medicines and vaccines, some of the worst diseases in history have
become preventable. Like, smallpox is totally eradicated. And we’re within jabbing distance of eliminating
polio, too. Getting here hasn’t been easy, though. These accomplishments are thanks to tremendous,
global efforts to get medicine to essentially the entire
human population, from American suburbs to the most remote inhabited
regions. But getting medicine to everyone on the planet
comes with some interesting challenges, because these drugs can be… finicky. Some of them are pretty stable, no matter
the conditions. But others are highly sensitive to light,
humidity, and especially heat. Like, some medicines should be kept between
two and eight degrees Celsius… which isn’t a lot of wiggle room. In rich, developed nations, meeting these
requirements is often doable thanks to elaborate, carefully-controlled
supply chains — systems that get medicine from the lab to
the patient while maintaining its quality. But for less developed areas — especially
those without easy, reliable access to an electrical grid — this can be a serious
problem. Coolers and ice packs can be a good last step
if you need to fly, drive, or hike a vaccine or medicine to a remote community. But to really address the problem, we need
solutions that can last a long time and that can be more precisely controlled. We need systems that can actually sense when
conditions are getting too hot or too cold and can readjust. And luckily, engineers have come up with some
options. One alternative that’s been used for a long
time is kerosene or gas-powered fridges. And before you ask, these aren’t just fridges
hooked up to gas-powered generators. They work thanks to clever engineering and
physics. First, you take a liquid refrigerant, like
ammonia, and put it in a sealed container at low pressure. The low pressure makes the liquid ammonia
start to evaporate and turn into a gas. This change in its physical state absorbs
heat from the surrounding environment — kind of like how evaporating sweat cools your
skin. This sucks heat away from the inside of the
fridge, chilling it down. Then, the ammonia gas is piped into a different
container filled with water, where it mixes and forms a solution. That solution is boiled with the help of burning
gas or kerosene, then the resulting vapors are passed through
a series of separators and condensers. Ultimately, you end up separating the ammonia
and water, so the ammonia can flow back into its original
chamber and start the cooling process all over again. Different models might be set up slightly
differently or use different chemicals, but that’s essentially it. And this cycle can be repeated for about as
long as you have gas to burn. Temperature, meanwhile, can be controlled
manually or with a thermostat. And a thermometer and recorder can warn doctors if the machine ever accidentally got too hot
or cold . Kerosene fridges were actually some of the
earliest models of refrigerators, and the old-school stuff sometimes works pretty
well. This has been a common way to keep medicine
cold in remote areas for the last 35 years or so, and these fridges
are used in more than 60% of vaccine storage locations. Of course, they aren’t exactly simple. These things need consistent shipments of
fuel, and they’re not super-efficient, so they’re now starting to be phased out
in favor of better and simpler options. Like, for example, solar-powered fridges. These are refrigerators powered by solar panels,
and like kerosene fridges, they can come with thermostats and temperature
readers. These devices first really came onto the scene
in the 1980s. But unfortunately, while they did fix the
problem of having to keep buying fuel, they also needed big battery systems to run
at night, which could break or be expensive to repair
and replace. So since about 2010, the preferred technology
is what are called solar direct-drives. They still use solar panels, but instead of
using that energy to charge batteries, they use it to directly freeze something like
water. That keeps the medicine cool, and the ice
will last for up to a few days even when the sun goes away. They can also use something called phase-change
material, which freezes like water, but at a bit higher
temperature — like 5 degrees Celsius, rather than 0. This still keeps things cool, but is less
prone to accidentally getting too cold. Regardless, these materials don’t keep refrigerators
cool for as long as an array of batteries might, so these things
might not be as good for places with regular, heavy cloud cover. But when you’re in an area with lots of
sun, a short charge is good enough to keep everything
frozen. These devices haven’t been extensively tested
in the field yet, so it’s hard to make sweeping statements
about their lifespan. But we have gotten promising results about
their reliability and ease of use out of field tests in Tanzania, Colombia,
and Kenya. While these things are more expensive to buy
up front, they seem to be simpler and cheaper in the
long run. And with more being developed all the time, the medical community will probably see a
lot more of them. Of course, solar direct-drives and kerosene
or gas fridges aren’t our only options for transporting
medicines. New research and design are happening all
the time, and that’s pushing us into some interesting
territory. For example, one project invented what’s
essentially a keg-sized, heavy-duty super-thermos that could be carried
during a hike or a field trip and that could stay cold for more than a month. Vaccines in the center of the device are surrounded
by ice blocks, and the entire inside compartment is then
surrounded by insulation and a vacuum chamber, which keeps heat from
the outside getting in. Small, onboard temperature sensors and electronics
can also sound an alarm if the system gets too cold, which might alert
doctors to open it up and re-pack things or move the vaccines somewhere
else. This container was added to the World Health
Organization’s list of prequalified products in 2015. If a country or NGO is looking to buy or donate medical equipment, this list tells them what the WHO thinks is up to the job. It is not, however, the only option in development. Student and design competitions have also
come up with coolers that could be run off things like hand-cranks
— basically, by using mechanical energy to power
a generator. And other designs miniaturize existing technology
to portable sizes. So whether it’s tried and true, new and
improved, or the cutting-edge, we’re working on solving this transportation
problem. Medically, we’ve already proven that we
have what it takes to treat or even wipe out some diseases. Now, we just have to keep our cool to put
the rest of them on ice. Thanks for watching this episode of SciShow,
and special thanks to Emerson for helping us make it! If you want to learn more about who Emerson
is and what they’re about, you can go to [♪ OUTRO]

100 thoughts on “How Engineers Move Medicine Around the World

  1. Growing up we didn’t have electricity so we had a propane refrigerator. It’s cool to see the technology has been used in other useful things.

  2. I wonder if we are gonna get like extremist anti vaxxers that will attack medicine deliveries and believe they are doing the right thing.

  3. we have to solve medical problems – (kinda) solved
    we have to solve engineering problems – (kinda) solved
    we have to convince people that vaccines and medicine help – we are (kinda) fxxxed

  4. @SciShow I find it quite annoying when you folks giving credits to physicians on tasks that they won't do. Let's be real here, physicians aren't the ones checking medication storage temperature, they aren't the ones that are ensuring the temperature are maintain within range. By giving credits to physicians on tasks they don't do you are presenting this facade that doctors do everything -it's shoving all the allied health and support staff under the bus.

  5. On a QI episode they mentioned early vaccines being shipped around the world in orphans, I was disappointed that it wasn't mentioned here.

  6. Ammonia absorption refrigerators used to be pretty popular. My grandma had one powered by natural gas in her kitchen. I forget who made them, but the tag line of one of the manufacturers was, "The Flame That Cools."

  7. Congratulations! You made it through the entire video referring only to Medicines, avoiding the dreaded V-word. Shhh! Don't annoy the trolls!

  8. I've always wondered how those refrigerators worked. Thank you SciShow for yet again answering a question I forgot to ask.

  9. nao nao, might be our gud ol' friens be comin' back, thar be these gawd fearin' gud ol' folks' who be skepchtethicatilal 'bout all that waxin', pretty lil boils on all crook'd childrenses (:

  10. I'm old enough to remember when these two diseases (small pox, polio) were still afflicting Americans, when It was 5 or 6 I got my small pox vaccination that was in the early 60's and and the polio vaccine had just been produced as an oral vaccine, both of them were painless and didn't require injections (back then there weren't disposable single use syringes they had to be sharpened and autoclaved, they were dull and painful), these vaccines absolutely saved countless lives. These anti – vaxers are relying on junk science that supposedly linked vaccinations to autism which has quite soundly been debunked. They are needlessly putting their children at serious risk of death and permanent disability. The schools that I went to REQUIRED immunization records to even enroll, I believe that all schools should follow suit or be charged with child endangerment.

  11. Hurry up anti vaxers. … get your kids infected so we can get this over with. Measles parties! Mumps rub ups! Let's see if you can get your kids good n sick. Yay!!!!!!

  12. Love all of the Scishow vids-you guys rock, but why does everyone flail their arms around so much?

    I can only gather there is some director person telling everyone not to stand still and to be animated lol but its a bit distracting and now that I've seen it with all of your presenters its pretty much all I notice when watching :Z

  13. That liquid-smooth conclusion as Hank drops his voice a solid octave below melting point to pack up the vividly freezing contents of this video gets me harder than an icicle chilling on the top of an Icelandic ice cave 6:30

  14. But… But… Vaccines cause autism! We all need to get our immunity naturally! You know, like my Grandfather and his siblings did! Only 5 of the 17 of them died before the age of 12! The rest had super-strong naturally-obtained immunity to diseases!

    Yeah, that's sarcasm, in case you can't tell. Anti-vaxxers really piss me off with their ignorance. 🙁

  15. Hysteresis of rubber band can also be used to cool something down. Essentially it just uses lots of rubber bands.

  16. I'm still unhappy with how Hank supported the Vox guy's vendetta against YouTube and hurting small independent creators. Hank why don't you do less videos and let the other folks take over for awhile. Every time I see your face I think about all the channels you helped get demonatized.

    Besides you could work more on your book.

  17. While completely ignoring the aspect of social trust – which is a serious part of getting people to ACCEPT medical aid.

  18. Why not use the persons motion of hiking the meds to power the cooler? Or even a wheel cart kind of thing. As the person pulls it along the wheels generate the power for the cooler.

  19. Engineering is really all about inventing methods to transfer information from one place to another with the power of science. Information can be literally anything, and that is why there are so many different kinds of engineers.

  20. Why not use an RTG?
    Americium can now be used, so no long-term disposal issues, no proliferation issues. Micro reactors don't produce enough energy to melt down in any case. It's the perfect fuel source for this application.

  21. this maybe a random place to put this comment, but I really, really, enjoy your videos and I'm glad that you guys work as hard as you do to put them out here for us to enjoy. I can't yet join your patreon people but I'm grateful you're here for us all the same. Hope you guys enjoy the fruits of your labor and the knowledge that we the general people are watching (and learning). 🙂

  22. We have an old kerosene fridge that was from my grandpa. We use it in a house in an island in the river were we go fishing.
    Didn't know they were used for meds

  23. Has anyone seen Mosquito Coast with River Phoenix? I think this is how his dad was making ice in the Caribbean …

  24. Cool video! You should mention a tiny DIY fridge by Emily Cummins that is literally two cans and some soil, all you have to do is water it (and the water doesn't even need to be clean).As the water evaporates from the soil between the cans, it pulls heat from the inner chamber. Surprisingly effective, and can be made in minutes.

    It's probably not as stable as a powered fridge and won't get very cold, but it's much much better than nothing.

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