How do gas masks actually work? - George Zaidan

539,867 views ใƒป 2024-04-30

TED-Ed


ืื ื ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ืœืžื˜ื” ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ.

ืชืจื’ื•ื: Shahar Berkovich ืขืจื™ื›ื”: zeeva livshitz
00:10
You might think of gas masks as clunky, spooky, military-looking devices
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ื›ืฉืืชื ื—ื•ืฉื‘ื™ื ืขืœ ืžืกื›ื•ืช ื’ื–, ืืชื ื‘ื˜ื— ืžื“ืžื™ื™ื ื™ื ืื•ืชืŸ ื›ืžื›ืฉื™ืจื™ื ืžื’ื•ืฉืžื™ื, ืžืคื—ื™ื“ื™ื ื•ืฆื‘ืื™ื™ื
00:14
only found in spy movies or World War I museums.
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ืฉืจื•ืื™ื ืื•ืชืŸ ืจืง ื‘ืกืจื˜ื™ ืจื™ื’ื•ืœ ืื• ื‘ืžื•ื–ื™ืื•ื ื™ื ืฉืœ ืžืœื—ืžืช ื”ืขื•ืœื ื”ืจืืฉื•ื ื”.
00:18
But you probably already own a mask that uses remarkably similar technology.
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ืื‘ืœ ืกื‘ื™ืจ ืœื”ื ื™ื— ืฉื›ื‘ืจ ื™ืฉ ืœื›ื ืžืกื›ื” ื”ืžืฉืชืžืฉืช ื‘ื˜ื›ื ื•ืœื•ื’ื™ื” ื“ื•ืžื” ืœื”ืคืœื™ื.
00:23
And in the near future, we may need to rely on these filters
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ื•ื‘ืขืชื™ื“ ื”ืงืจื•ื‘, ื™ื™ืชื›ืŸ ืฉื ืฆื˜ืจืš
ืœื”ืกืชืžืš ืขืœ ื”ืกื™ื ื•ืŸ ืฉื‘ืžืกื›ื•ืช
00:25
as part of our everyday lives.
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ื›ื—ืœืง ืžื—ื™ื™ ื”ื™ื•ืžื™ื•ื ืฉืœื ื•.
00:28
In addition to emerging diseases,
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ื‘ื ื•ืกืฃ ืœืžื—ืœื•ืช ืžืชืขื•ืจืจื•ืช,
00:30
wildfire frequency has more than tripled from 1996 to 2021.
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ืชื“ื™ืจื•ืช ื”ืฉืจื™ืคื•ืช ื’ื“ืœื” ืคื™ 3 ืžืฉื ืช 1996 ืขื“ 2021.
00:35
As fires burn longer and cover more land, their smoke affects more people each year.
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ื›ื›ืœ ืฉืฉืจื™ืคื•ืช ื‘ื•ืขืจื•ืช ื•ืžื›ืกื•ืช ืขืœ ืขื•ื“ ืฉื˜ื—, ื”ืขืฉืŸ ืฉืœื”ืŸ ืžืฉืคื™ืข ืขืœ ื™ื•ืชืจ ืื ืฉื™ื ืžื“ื™ ืฉื ื”.
00:40
Climate change is also causing more hot, sunny days,
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ื‘ื ื•ืกืฃ, ืฉื™ื ื•ื™ ื”ืืงืœื™ื ื’ื•ืจื ืœื™ืžื™ ืฉืžืฉ ื—ืžื™ื ืžื”ืจื’ื™ืœ,
00:44
which accelerates the production of toxic ground level ozone.
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ืžื” ืฉืžืื™ืฅ ืืช ื™ื™ืฆื•ืจ ื”ืื•ื–ื•ืŸ ื”ืจืขื™ืœ ื‘ื’ื•ื‘ื” ื”ืงืจืงืข.
00:48
So, how do these masks work,
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ืื–, ืื™ืš ื”ืžืกื›ื•ืช ื”ืืœื• ืขื•ื‘ื“ื•ืช,
00:49
and can they protect us from new and old airborne threats?
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ื•ื”ืื ื”ืŸ ื™ื›ื•ืœื•ืช ืœื”ื’ืŸ ืขืœื™ื ื• ืžืคื ื™ ืื™ื•ืžื™ื ืžื•ื˜ืกื™ื ื—ื“ืฉื™ื ื•ื™ืฉื ื™ื?
00:52
Well, the first rule of filters is making sure you have a tight seal.
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ื•ื‘ื›ืŸ, ื”ื›ืœืœ ื”ืจืืฉื•ืŸ ืฉืœ ื”ืžืกื ื ื™ื ื”ื•ื ืœื•ื•ื“ื ืฉื”ื—ื•ืชื ื”ื“ื•ืง.
00:56
Without that, even the best mask in the world is useless.
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ื‘ืœื™ ื–ื”, ืืคื™ืœื• ื”ืžืกื›ื” ื”ื˜ื•ื‘ื” ื‘ืขื•ืœื ื”ื™ื ื—ืกืจืช ืชื•ืขืœืช.
00:59
So assuming your mask is on tight,
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ื‘ื”ื ื—ื” ืฉื”ืžืกื›ื” ืื›ืŸ ืฆืžื•ื“ื”,
01:01
this technology can capture pollutants in one of two ways:
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ื˜ื›ื ื•ืœื•ื’ื™ื™ืช ื”ืกื™ื ื•ืŸ ื™ื›ื•ืœื” ืœืœื›ื•ื“ ื–ื™ื”ื•ืžื™ื ื‘ืื—ืช ืžืฉืชื™ ื”ื“ืจื›ื™ื:
01:05
filtering them out by size or attracting specific chemical compounds.
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ืกื™ื ื•ืŸ ืขโ€œืค ื’ื•ื“ืœ ืื• ืžืฉื™ื›ืช ืชืจื›ื•ื‘ื•ืช ื›ื™ืžื™ื•ืช ืกืคืฆื™ืคื™ื•ืช.
01:09
For an example of the first approach, letโ€™s look at wildfire smoke.
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ืขื‘ื•ืจ ื“ื•ื’ืžื” ื‘ืฉื‘ื™ืœ ื”ื’ื™ืฉื” ื”ืจืืฉื•ื ื”: ื‘ื•ืื• ื ื‘ื—ืŸ ืขืฉืŸ ื‘ืฉื“ื” ืงื•ืฆื™ื.
01:13
When forests burn, they generate a wide variety of chemicals.
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ื›ืืฉืจ ื™ืขืจื•ืช ื ืฉืจืคื™ื, ื”ื ืžื™ื™ืฆืจื™ื ืžื’ื•ื•ืŸ ืจื—ื‘ ืฉืœ ื›ื™ืžื™ืงืœื™ื.
01:17
At close range, there are so many different pollutants
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ื‘ืžื‘ื˜ ืžืงืจื•ื‘, ื™ืฉื ื ื›โ€œื› ื”ืจื‘ื” ืžื–ื”ืžื™ื ืฉื•ื ื™ื
01:19
at such high concentrations that no filter could help youโ€”
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ื‘ืจื™ื›ื•ื–ื™ื ืขื“ ื›ื“ื™ ื›ืš ื’ื‘ื•ื”ื™ื ืฉืืฃ ืกื™ื ื•ืŸ ืœื ื™ื›ื•ืœ ืœืขื–ื•ืจ
01:22
this is why firefighters travel with their own air supply.
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ื–ื• ื”ืกื™ื‘ื” ืฉื›ื‘ืื™ื ื ื•ืกืขื™ื ืขื ืืกืคืงืช ืื•ื•ื™ืจ ืžืฉืœื”ื.
01:25
But further away, the situation is different.
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ื‘ืžื‘ื˜ ืžืจื—ื•ืง, ื”ืžืฆื‘ ืฉื•ื ื”.
01:28
While there's still a range of chemicals,
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ืืžื ื ืขื“ื™ื™ืŸ ื™ืฉ ืžื’ื•ื•ืŸ ื›ื™ืžื™ืงืœื™ื,
01:30
theyโ€™ve mostly aggregated into tiny solid or liquid particles
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ืืš ื”ื ื”ืชื—ืœืงื• ื‘ืขื™ืงืจ ืœืžื•ืฆืงื™ื ื–ืขื™ืจื™ื ืื• ืœื—ืœืงื™ืงื™ื ื ื•ื–ืœื™ื™ื
01:34
smaller than 2.5 microns in diameter.
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ืฉืงื•ื˜ืจื ืงื˜ืŸ ืž-2.5 ืžื™ืงืจื•ืŸ (1 ืžื™ืงืจื•ืžื˜ืจ = 0.001 ืžื™ืœื™ืžื˜ืจ).
01:37
This particulate matter is much of what you're seeing and smelling in smoke,
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ื”ื—ื•ืžืจ ื”ื—ืœืงื™ืงื™ ื”ื–ื” ื”ื•ื ืžื” ืฉืืชื ืจื•ืื™ื ื•ืžืจื™ื—ื™ื ื›ืฉื™ืฉ ืขืฉืŸ,
01:41
and it's especially dangerous for children, the elderly,
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ื•ื”ื•ื ืžืกื•ื›ืŸ ื‘ืžื™ื•ื—ื“ ืœื™ืœื“ื™ื, ืงืฉื™ืฉื™ื
01:44
and those with respiratory or cardiovascular diseases.
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ื•ืืœื” ื”ืกื•ื‘ืœื™ื ืžืžื—ืœื•ืช ื ืฉื™ืžื” ืื• ืœื‘ ื•ื›ืœื™ ื“ื.
01:47
Luckily, the majority of these particulates are still large enough
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ืœืžืจื‘ื” ื”ืžื–ืœ, ืจื•ื‘ ื”ื—ืœืงื™ืงื™ื ื”ืœืœื• ืขื“ื™ื™ืŸ ื’ื“ื•ืœื™ื ืžืกืคื™ืง
01:50
to be captured by the most basic filters,
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ื›ื“ื™ ืœื”ื™ืชืคืก ืขืœ ื™ื“ื™ ื”ืžืกื ื ื™ื ื”ื‘ืกื™ืกื™ื™ื ื‘ื™ื•ืชืจ,
01:53
which are made of polypropylene or glass strands
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ื”ืขืฉื•ื™ื™ื ืžื—ื•ื˜ื™ ืคื•ืœื™ืคืจื•ืคื™ืœืŸ ืื• ื–ื›ื•ื›ื™ืช
01:55
roughly 1/10 the width of a human hair.
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ืฉื”ื ื‘ืขืจืš ืขืฉื™ืจื™ืช ืžืจื•ื—ื‘ ืฉืขืจื” ืื ื•ืฉื™ืช.
01:58
Under a microscope, they look like a thick forest,
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ืชื—ืช ืžื™ืงืจื•ืกืงื•ืค, ื”ื ื ืจืื™ื ื›ืžื• ื™ืขืจ ืกืžื™ืš,
02:01
and at this scale, these branches have a special property.
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ื•ื‘ืงื ื” ืžื™ื“ื” ื–ื”, ืœืขื ืคื™ื ืืœื” ื™ืฉ ืชื›ื•ื ื” ืžื™ื•ื—ื“ืช.
02:05
Typically, when you use a sieve,
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ื‘ื“ืจืš ื›ืœืœ, ื›ืืฉืจ ืืชื ืžืฉืชืžืฉื™ื ื‘ืžืกื ื ืช,
02:07
youโ€™re filtering out objects larger than the sieveโ€™s holes.
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ืืชื ืžืกื ื ื™ื ื—ืคืฆื™ื ื’ื“ื•ืœื™ื ื™ื•ืชืจ ืžื—ื•ืจื™ ื”ืžืกื ื ืช.
02:11
But these polypropylene branches can catch particles much smaller
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ืื‘ืœ ืขื ืคื™ ืคื•ืœื™ืคืจื•ืคื™ืœืŸ ืืœื” ื™ื›ื•ืœื™ื ืœืชืคื•ืก ื—ืœืงื™ืงื™ื ืงื˜ื ื™ื
02:15
than the gaps between them.
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ื‘ื”ืจื‘ื” ืžื”ืคืขืจื™ื ืฉื‘ื™ื ื™ื”ื.
02:17
Thatโ€™s because, when a particle collides with a thread,
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ื”ืกื™ื‘ื” ืœื›ืš ื”ื™ื ืฉื›ืืฉืจ ื—ืœืงื™ืง ืžืชื ื’ืฉ ื‘ื—ื•ื˜,
02:19
van der Waals forces cause it to stick as if it were made of Velcro.
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ืงืฉืจื™ ื•ืืŸ ื“ืจ ื•ืืœืก ื’ื•ืจืžื™ื ืœื• ืœื”ื™ื“ื‘ืง ืืœ ื”ืขื ืฃ ื›ืื™ืœื• ื”ื™ื” ืขืฉื•ื™ ืžืกืงื•ื˜ืฉ.
02:24
Plus, size-based filters can use electrically charged fibers
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ื‘ื ื•ืกืฃ, ืžืกื ื ื™ื ืžื‘ื•ืกืกื™ ื’ื•ื“ืœ ื™ื›ื•ืœื™ื ืœื”ืฉืชืžืฉ ื‘ืกื™ื‘ื™ื ื˜ืขื•ื ื™ื ื—ืฉืžืœื™ืช
02:28
that attract particles not already on a collision course.
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ื”ืžื•ืฉื›ื™ื ื—ืœืงื™ืงื™ื ืฉืื™ื ื ื‘ืžืกืœื•ืœ ื”ืชื ื’ืฉื•ืช.
02:32
This is how even a simple N95 mask can catch at least 95% of particulate matter.
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ื›ืš ืืคื™ืœื• ืžืกื›ืช N95 ืคืฉื•ื˜ื” ื™ื›ื•ืœื” ืœืชืคื•ืก ืœืคื—ื•ืช 95% ืžื”ื—ืœืงื™ืงื™ื.
02:38
And why an N100 mask
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ื•ืžื“ื•ืข ืžืกื›ืช N100
02:40
or an air purifier with a high efficiency particulate air filter
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ืื• ืžื˜ื”ืจ ืื•ื•ื™ืจ ืขื ืžืกื ืŸ ืื•ื•ื™ืจ ื—ืœืงื™ืงื™ ื‘ืขืœ ื™ืขื™ืœื•ืช ื’ื‘ื•ื”ื”
02:43
can catch at least 99.97% of particulates.
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ื™ื›ื•ืœื™ื ืœืชืคื•ืก ืœืคื—ื•ืช 99.97% ืžื”ื—ืœืงื™ืงื™ื.
02:47
With a tight seal,
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ืขื ื—ื•ืชื ื”ื“ื•ืง,
02:49
this level of protection will filter out most airborne pollution.
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ื”ืžืกื ืŸ ื™ืฆืœื™ื— ืœืกื ืŸ ืืช ืจื•ื‘ ื”ื–ื™ื”ื•ื ื”ื ืžืฆื ื‘ืื•ื•ื™ืจ.
02:53
Unfortunately, some pollutants are still too small for this approach,
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ืืš ืœืžืจื‘ื” ื”ืฆืขืจ, ื™ืฉื ื ื–ื™ื”ื•ืžื™ื ืืฉืจ ืขื“ื™ื™ืŸ ืžืฆืœื™ื—ื™ื ืœืขื‘ื•ืจ ืœืžืจื•ืช ื”ื—ื•ืชื ื”ื”ื“ื•ืง.
02:56
including ozone molecules.
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ื‘ื™ื ื™ื”ื, ืžื•ืœืงื•ืœื•ืช ืื•ื–ื•ืŸ.
02:58
These are barely bigger than the oxygen that we need to breathe
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ืžื•ืœืงื•ืœื•ืช ืฉื‘ืงื•ืฉื™ ื’ื“ื•ืœื•ืช ื™ื•ืชืจ ืžืžื•ืœืงื•ืœื•ืช ื”ื—ืžืฆืŸ ืฉืื ื—ื ื• ื ื•ืฉืžื™ื
03:02
and exposure is associated with asthma, respiratory conditions,
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ื•ื”ื—ืฉื™ืคื” ืžืชืงืฉืจืช ืœืืกื˜ืžื”, ืžืฆื‘ื™ ื ืฉื™ืžื”
03:05
and even premature death.
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ื•ืืคื™ืœื• ืžื•ื•ืช ื‘ื˜ืจื ืขืช.
03:08
Our best chance to filter them are activated carbon masks.
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ื”ืกื™ื›ื•ื™ ื”ื˜ื•ื‘ ื‘ื™ื•ืชืจ ืฉืœื ื• ืœืกื ืŸ ืื•ืชื ื”ืŸ ืžืกื›ื•ืช ื”ืคื—ืžืŸ ื”ืคืขื™ืœ.
03:11
At the microscopic level, activated carbon looks like a vast black honeycomb,
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ื‘ืจืžื” ื”ืžื™ืงืจื•ืกืงื•ืคื™ืช, ืคื—ืžืŸ ืคืขื™ืœ ื ืจืื” ื›ืžื• ื—ืœืช ื“ื‘ืฉ ืฉื—ื•ืจื” ืขืฆื•ืžื”,
03:16
and it's highly microporous structure can trap tiny ozone molecules.
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ื•ื”ืžื‘ื ื” ื”ืžื™ืงืจื•-ื ืงื‘ื•ื‘ื™ ืฉืœื• ื™ื›ื•ืœ ืœืœื›ื•ื“ ืžื•ืœืงื•ืœื•ืช ืื•ื–ื•ืŸ ื–ืขื™ืจื•ืช.
03:21
But this material still needs help to capture other pollutants
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ืืš ื—ื•ืžืจ ื–ื” ืขื“ื™ื™ืŸ ื–ืงื•ืง ืœืขื–ืจื” ืœืœื›ื™ื“ืช ืžื–ื”ืžื™ื ืื—ืจื™ื
03:24
like hydrogen sulfide, chlorine, and ammonia.
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ื›ืžื• ืžื™ืžืŸ ื’ื•ืคืจืชื™, ื›ืœื•ืจ ื•ืืžื•ื ื™ื”.
03:27
For these threats, we need to combine the activated carbon
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ืขื‘ื•ืจ ืื™ื•ืžื™ื ืืœื”, ืขืœื™ื ื• ืœืฉืœื‘ ืืช ื”ืคื—ืžืŸ ื”ืคืขื™ืœ
03:30
with some simple chemistry.
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ืขื ื›ื™ืžื™ื” ืคืฉื•ื˜ื”.
03:32
If the pollutant is acidic, we can infuse the filter with a basic chemical.
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ืื ื”ืžื–ื”ื ื—ื•ืžืฆื™, ื ื•ื›ืœ ืœื”ื—ื“ื™ืจ ืืช ื”ืžืกื ืŸ ื‘ื›ื™ืžื™ืงืœ ื‘ืกื™ืกื™.
03:37
Then when the two meet, they react, and the gas is trapped.
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ื•ืื– ื›ืฉื”ืฉื ื™ื™ื ื ืคื’ืฉื™ื, ื”ื ืžื’ื™ื‘ื™ื, ื•ื”ื’ื– ื ืœื›ื“.
03:40
Similarly, we can use acids to trap basic pollutants.
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ื‘ืื•ืคืŸ ื“ื•ืžื”, ืื ื• ื™ื›ื•ืœื™ื ืœื”ืฉืชืžืฉ ื‘ื—ื•ืžืฆื•ืช ื›ื“ื™ ืœืœื›ื•ื“ ืžื–ื”ืžื™ื ื‘ืกื™ืกื™ื™ื.
03:44
Even with the right mask, it's still smart to check air quality indicators
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ื’ื ื›ืฉื—ื•ื‘ืฉื™ื ืืช ื”ืžืกื›ื” ื”ื ื›ื•ื ื”, ืขื“ื™ืฃ ืœื‘ื“ื•ืง ืื™ื ื“ื™ืงื˜ื•ืจื™ื ืœืื™ื›ื•ืช ื”ืื•ื•ื™ืจ
03:48
and to stay indoors when the threat level is high.
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ื•ืœื”ื™ืฉืืจ ื‘ื‘ื™ืช ื›ืืฉืจ ืจืžืช ื”ืื™ื•ื ื’ื‘ื•ื”ื”.
03:51
And just like a mask, you'll want to make sure your house is well sealed.
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ื•ื‘ื“ื™ื•ืง ื›ืžื• ืžืกื›ื”, ืชืจืฆื• ืœื•ื•ื“ื ืฉื”ื‘ื™ืช ืฉืœื›ื ืื˜ื•ื ื”ื™ื˜ื‘.
03:55
You can do this by closing windows, turning off fans that vent outside,
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ืืชื ื™ื›ื•ืœื™ื ืœืขืฉื•ืช ื–ืืช ืขโ€œื™ ืกื’ื™ืจืช ื—ืœื•ื ื•ืช, ื›ื™ื‘ื•ื™ ืžืื•ื•ืจืจื™ื ื”ืขื•ื‘ื“ื™ื ืžื‘ื—ื•ืฅ
03:59
and using HEPA filter equipped air purifiers
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ื•ืฉื™ืžื•ืฉ ื‘ืžื˜ื”ืจื™ ืื•ื•ื™ืจ ืžืฆื•ื™ื“ื™ื ื‘ืžืกื ืŸ HEPA
04:01
or their cheaper, DIY cousin, the Corsi-Rosenthal box.
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ืื• ื‘ืŸ ื“ื•ื“ื ื”ื–ื•ืœ ื™ื•ืชืจ, ืขืฉื” ื–ืืช ื‘ืขืฆืžืš, ืชื™ื‘ืช ืงื•ืจืกื™-ืจื•ื–ื ื˜ืœ.
04:06
Following these guidelines can help us breathe easy
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ื‘ื™ืฆื•ืข ื”ื ื—ื™ื•ืช ืืœื” ื™ื›ื•ืœ ืœืขื–ื•ืจ ืœื ื• ืœื ืฉื•ื ื‘ืงืœื•ืช
04:09
as we work on preventing these pollutants in the first place.
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ื›ืฉืื ื—ื ื• ืขื•ื‘ื“ื™ื ืขืœ ืžื ื™ืขืช ืžื–ื”ืžื™ื ืืœื” ืžืœื›ืชื—ื™ืœื”.
ืขืœ ืืชืจ ื–ื”

ืืชืจ ื–ื” ื™ืฆื™ื’ ื‘ืคื ื™ื›ื ืกืจื˜ื•ื ื™ YouTube ื”ืžื•ืขื™ืœื™ื ืœืœื™ืžื•ื“ ืื ื’ืœื™ืช. ืชื•ื›ืœื• ืœืจืื•ืช ืฉื™ืขื•ืจื™ ืื ื’ืœื™ืช ื”ืžื•ืขื‘ืจื™ื ืขืœ ื™ื“ื™ ืžื•ืจื™ื ืžื”ืฉื•ืจื” ื”ืจืืฉื•ื ื” ืžืจื—ื‘ื™ ื”ืขื•ืœื. ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ื”ืžื•ืฆื’ื•ืช ื‘ื›ืœ ื“ืฃ ื•ื™ื“ืื• ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ ืžืฉื. ื”ื›ืชื•ื‘ื™ื•ืช ื’ื•ืœืœื•ืช ื‘ืกื ื›ืจื•ืŸ ืขื ื”ืคืขืœืช ื”ื•ื•ื™ื“ืื•. ืื ื™ืฉ ืœืš ื”ืขืจื•ืช ืื• ื‘ืงืฉื•ืช, ืื ื ืฆื•ืจ ืื™ืชื ื• ืงืฉืจ ื‘ืืžืฆืขื•ืช ื˜ื•ืคืก ื™ืฆื™ืจืช ืงืฉืจ ื–ื”.

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