W*****B
发帖数: 4796 | 1 Should I wear a mask?
For health-care workers, the answer is obviously yes. But which masks? The
World Health Organization and the Centers for Disease Control and Prevention
both state that doctors and nurses can use basic surgical masks when
treating COVID-19 patients, switching to the more advanced N95 respirators
if they’re carrying out procedures that might create aerosols. But such
recommendations assume that the virus isn’t generally airborne. Because it
might be, health-care workers should err on the side of precaution by
wearing N95s and using even better respirators for more dangerous procedures
, argues Lisa Brousseau of the University of Illinois at Chicago. All of
this equipment is in short supply, but health-care workers at least deserve
to know what the ideal measures are.
For everyone else, the debate is even trickier. For months, the WHO, the CDC
, and most public-health professionals have advised that people don’t need
to wear face masks unless they have COVID-19 or are caring for someone who
does. At the same time, these experts have noted that health-care workers
are in dire need of masks, which are running out because of strained supply
chains and surging patient numbers. On February 29, the U.S. surgeon general
, Jerome Adams, tweeted, “Seriously people- STOP BUYING MASKS! They are NOT
effective in preventing general public from catching #Coronavirus, but if
healthcare providers can’t get them to care for sick patients, it puts them
and our communities at risk!”
If masks are limited, conserving them for the people who need them most
makes sense. But that message was lost amid the confusing claim that masks
somehow protect health-care workers but are useless for everyone else. In
recent weeks, that simmering tension has come to a boil. Opinion pieces,
news stories, and scientific papers have urged Western countries to use
masks widely, emulating the example set by East Asian countries. Masks are
mandatory for anyone entering a supermarket in Austria, and anyone leaving
their house in the Czech Republic and Slovakia. In the U.S., the CDC is
reportedly contemplating a change in guidance, and many public-health
experts have already pivoted. “I went with the public-health message at the
beginning: People don’t need masks,” Marr said. “But I’ve changed
because of the mounting evidence that it does seem to be spreading through
the air.”
[Read: America needs plasma from COVID-19 survivors now]
If the virus is traveling through the air, then it seems intuitive that
masks would block it. But the evidence for this is all over the place,
especially for surgical masks, which are more common than N95 respirators,
and which don’t form a tight seal with the face. Several past studies have
found that face masks could reduce the risk of flu-like infections, slow flu
transmission in households, and even reduce the spread of SARS, especially
when combined with hand-washing and gloves. Other studies have been more
equivocal, finding that masks provide no benefit, small benefits, or
benefits only in conjunction with measures like hand-washing. “Airflow
follows the path of least resistance, and if it won’t enter through the
mesh, it can come in from the side,” Bourouiba said. “There’s no evidence
whatsoever to suggest that [surgical masks] are protective against the
smallest droplets.”
There’s still a good case for masks, though, even if they can’t stop
viruses from getting in: They can stop viruses from getting out. “I’ve
been slightly dismissive of masks, but I was looking at them in the wrong
way,” Harvard’s Bill Hanage told me. “You’re not wearing them to stop
yourself getting infected, but to stop someone else getting infected.” This
might be especially important for SARS-CoV-2, which can spread without
immediately causing symptoms. If people are infectious before they fall sick
, then everyone should wear face masks “when going out in public, in one
additional societal effort to slow the spread of the virus down,” says
Thomas Inglesby of the John Hopkins Center for Health Security.
Some commentators have argued that countries that have thus far succeeded in
curbing their COVID-19 outbreaks have widely used masks. But this
relationship isn’t as perfect as it might appear. China advocated mask use
early on and still struggled to contain the disease. Japan uses masks widely
but is now seeing an uptick in cases. Singapore reserved them for health-
care workers but still flattened the curve of infections. Many successful
mask-using countries relied on other measures, such as extensive testing and
social distancing, and many were ready for the pandemic because of their
prior run-in with the 2003 SARS epidemic.
In Asia, masks aren’t just shields. They’re also symbols. They’re an
affirmation of civic-mindedness and conscientiousness, and such symbols
might be important in other parts of the world too. If widely used, masks
could signal that society is taking the pandemic threat seriously. They
might reduce the stigma foisted on sick people, who would no longer feel
ashamed or singled out for wearing one. They could offer reassurance to
people who don’t have the privilege of isolating themselves at home, and
must continue to work in public spaces. “My staff have also mentioned that
having a mask reminds them not to touch their face or put a pen in their
mouth,” Bourouiba noted.
Or masks could have the opposite effect. Whenever Santarpia sees someone
wearing a mask in public, that person is constantly touching it, futzing
with it, and pulling it down to wipe their mouth. “Masks are really
uncomfortable, and no one wears them correctly,” he said. “Rather than
being protective, you’ve put something on your face that makes you want to
touch your face more, or to touch the outside of the mask, which is
infectious. You’ve created a hazard for yourself that’s right on your face
.”
Many public-health experts have voiced similar complaints, based on their
own personal experience. But it’s hard to find studies showing that novice
mask-users touch their face more, or that such behavior increases the risk
of infection. Regardless, if people misuse masks, why not train them?
Countless videos and memes have been made to show people how to wash their
hands properly, and the WHO already has a good instructional video about
using masks. | W*****B
发帖数: 4796 | 2 The debate is somewhat moot right now, because there simply aren’t enough
masks for medical professionals, let alone everyone else. No matter their
opinions on widespread mask-wearing, everyone I spoke with for this article
agreed that health-care workers should get dibs on any existing medical
masks. This might well be why public-health officials have been so loath to
recommend mask-wearing more broadly: Hoarders have already begun to exhaust
the dwindling supplies. Even so, “policy shouldn’t be made to accommodate
a lack of the supply,” Bourouiba said. “It should create the impetus to
generate that supply.”
In the meantime, citizens (and, unfortunately, many health-care workers)
will have to make do with MacGyvering their own alternatives. A few studies
suggest that homemade cloth masks are less effective than proper medical
ones, but are still better than nothing. In one experiment, a surgical mask
filtered 96 percent of viral particles from the air, a tea towel blocked 83
percent, and a cotton T-shirt blocked 69 percent. In general, thicker
materials are better than thinner ones, Marr said, and a tight fit across
the face is important. If people use makeshift masks, they should thoroughly
wash them afterward. And most of all, they should remember that homemade
masks are not fully protective. They’re a last-ditch measure to be used in
situations when social distancing isn’t possible. “It’s not like ‘I’m
wearing [a mask] and now I can talk to everyone,’” Bourouiba said.
The mask debate is so intense because both the stakes and the uncertainty
levels are so high. “We’re trying to build the plane while we’re flying
it,” Hanage said. “We’re having to make decisions with quite massive
consequences in the absence of secure data. It’s a nightmare for your
average cautious public-health professional.”
The coronavirus pandemic has moved so quickly that years of social change
and academic debate have been compressed into a matter of months. Academic
squabbles are informing national policy. Long-standing guidelines are
shifting. Within days, an experiment that’s done in a hospital room can
affect how people feel about the very air around them, and what they choose
to wear on their faces. Masks are a symbol, yes, but not just of
conscientiousness. They’re also emblematic of a world that is changing so
quickly, no one has time to take a breath. | F*****d
发帖数: 2848 | 3 关键是没口罩，如果商场里到处能买到口罩就没这个矛盾了。 | n********g
发帖数: 6504 | 4 有病才戴口罩。自制口罩也是因为自己有病。
【在 F*****d 的大作中提到】
: 关键是没口罩，如果商场里到处能买到口罩就没这个矛盾了。
| b*****2
发帖数: 11103 | | f********g
发帖数: 32 | 6 用内裤
【在 F*****d 的大作中提到】
: 关键是没口罩，如果商场里到处能买到口罩就没这个矛盾了。
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