The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests.
This risk is highest in crowded indoor spaces with poor ventilation, and may help explain superspreading events reported in meatpacking plants, churches and restaurants.
It’s unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech.
Follow latest updates on the Covid-19 pandemic here
Aerosols are released even when a person without symptoms exhales, talks or sings, according to Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.
What is clear, they said, is that people should consider minimizing time indoors with people outside their families. Schools, nursing homes and businesses should consider adding powerful new air filters and ultraviolet lights that can kill airborne viruses.
What does it mean for a virus to be airborne?
For a virus to be airborne means that it can be carried through the air in a viable form. For most pathogens, this is a yes-no scenario. HIV, too delicate to survive outside the body, is not airborne. Measles is airborne, and dangerously so: It can survive in the air for up to two hours.
For the coronavirus, the definition has been more complicated. Experts agree that the virus does not travel long distances or remain viable outdoors. But evidence suggests it can traverse the length of a room and, in one set of experimental conditions, remain viable for perhaps three hours.
How are aerosols different from droplets?
Aerosols are droplets, droplets are aerosols — they do not differ except in size. Scientists sometimes refer to droplets fewer than 5 microns in diameter as aerosols. (By comparison, a red blood cell is about 5 microns in diameter; a human hair is about 50 microns wide.)
From the start of the pandemic, the WHO and other public health organizations have focused on the virus’s ability to spread through large droplets that are expelled when a symptomatic person coughs or sneezes.
These droplets are heavy, relatively speaking, and fall quickly to the floor or onto a surface that others might touch. This is why public health agencies have recommended maintaining a distance of at least 6 feet from others, and frequent hand washing.
But some experts have said for months that infected people also are releasing aerosols when they cough and sneeze. More important, they expel aerosols even when they breathe, talk or sing, especially with some exertion.
Scientists know now that people can spread the virus even in the absence of symptoms — without coughing or sneezing — and aerosols might explain that phenomenon.
Because aerosols are smaller, they contain much less virus than droplets do. But because they are lighter, they can linger in the air for hours, especially in the absence of fresh air. In a crowded indoor space, a single infected person can release enough aerosolized virus over time to infect many people, perhaps seeding a superspreader event.
For droplets to be responsible for that kind of spread, a single person would have to be within a few feet of all the other people, or to have contaminated an object that everyone else touched. All that seems unlikely to many experts: “I have to do too many mental gymnastics to explain those other routes of transmission compared to aerosol transmission, which is much simpler,” Marr said.
Can I stop worrying about physical distancing and washing my hands?
Physical distancing is still very important. The closer you are to an infected person, the more aerosols and droplets you may be exposed to. Washing your hands often is still a good idea.
What’s new is that those two things may not be enough. “We should be placing as much emphasis on masks and ventilation as we do with hand washing,” Marr said. “As far as we can tell, this is equally important, if not more important.”
Should I begin wearing a hospital-grade mask indoors? And how long is too long to stay indoors?
Health care workers may all need to wear N95 masks, which filter out most aerosols. At the moment, they are advised to do so only when engaged in certain medical procedures that are thought to produce aerosols.
For the rest of us, cloth face masks will still greatly reduce risk, as long as most people wear them. At home, when you’re with your own family or with roommates you know to be careful, masks are still not necessary. But it is a good idea to wear them in other indoor spaces, experts said.
As for how long is safe, that is frustratingly tough to answer. A lot depends on whether the room is too crowded to allow for a safe distance from others and whether there is fresh air circulating through the room.
What does airborne transmission mean for reopening schools and colleges?
This is a matter of intense debate. Many schools are poorly ventilated and are too poorly funded to invest in new filtration systems. “There is a huge vulnerability to infection transmission via aerosols in schools,” said Don Milton, an aerosol expert at the University of Maryland.
Most children younger than 12 seem to have only mild symptoms, if any, so elementary schools may get by. “So far, we don’t have evidence that elementary schools will be a problem, but the upper grades, I think, would be more likely to be a problem,” Milton said.
College dorms and classrooms are also cause for concern.
Milton said the government should think of long-term solutions for these problems. Having public schools closed “clogs up the whole economy, and it’s a major vulnerability,” he said.
“Until we understand how this is part of our national defense, and fund it appropriately, we’re going to remain extremely vulnerable to these kinds of biological threats.”
What are some things I can do to minimize the risks?
Do as much as you can outdoors. Despite the many photos of people at beaches, even a somewhat crowded beach, especially on a breezy day, is likely to be safer than a pub or an indoor restaurant with recycled air.
But even outdoors, wear a mask if you are likely to be close to others for an extended period.
When indoors, one simple thing people can do is to “open their windows and doors whenever possible,” Marr said. You can also upgrade the filters in your home air-conditioning systems, or adjust the settings to use more outdoor air rather than recirculated air.
Public buildings and businesses may want to invest in air purifiers and ultraviolet lights that can kill the virus. Despite their reputation, elevators may not be a big risk, Milton said, compared with public bathrooms or offices with stagnant air where you may spend a long time.
If none of those things are possible, try to minimize the time you spend in an indoor space, especially without a mask. The longer you spend inside, the greater the dose of virus you might inhale.
Comments
Ella sahodarammarkk oru advise, nanga nanga penagitt nangalo onnamatho dushman BJP gellum pole aakiranda, please please ninga ellarum onnaitt genduro chance ullo nangalo oru candidate barumpole aakonu, nangalo raya innoru UP do pole aakiranda
Brother,
Being in respectable position as a minister, he should have thought twice before making a statement. If somebody scribbles against him or speaks against him in social media like Fb and whatsapp let him file a case against them. Or let him condemn them. ಇವರನ್ನು ಟೀಕಿಸಿದವರೆಲ್ಲ ಢೋಂಗಿ ಮಾಡಿ ಗಲ್ಫ್ ಗೆ ಹೋದವರಾ? . ಧಾರ್ಮಿಕ ಕಾರ್ಯಕ್ರಮದಲ್ಲಿ ಮಾತನಾಡುವಾಗ ಸ್ವಲ್ಪ ಚಿಂತಿಸಿ ಮಾತನಾಡಿದರೆ ಅವರ ಘನತೆಗೆ ಒಳ್ಳೆಯದು.
In next election, people will decide who is the best loafer and teach him a good lesson. #Ashrafbhai Nxt Mla #UTK Koragajjana gudige
UT Khader Saab. Most of the NRIs from your region know very well that some of your opponents are not just loafers but are ugliest creatures and communal goons. But you don’t lose cool and respond to them in public. Let them go to hell. We are with you. You are a role model for many. So kindly don’t react to the loafers in their own language.
My humble request to UTK is to ignore the cheap level criticism by communal goons. Be it Bajrangis or SDPI. They really don’t deserve the attention of a great social worker and politician like UTK.
UT Khader has not twisted his statement. He never said that all NRIs are Dongi Maadi Gulf ge hodavaru. He said that Dongi Maddi gulf ge hodavaru trying to teach him how to live. And he doesn’t care them. That’s true. Nirva Modi and Vijay Malya also included in dongi parties.
ಯು. ಟಿ ಖಾದರ್ ಓರ್ವ ಶಾಸಕ ಹಾಗೂ ಸಚಿವ ಎಂಬ ಕಾರಣಕ್ಕಾಗಿ ಅವರನ್ನು ಎಲ್ಲಾ ಜಾತಿ, ಮತ, ಧರ್ಮ ಪಂಗಡದವರು ಅವರವರ ಧಾರ್ಮಿಕ ಕಾರ್ಯಕ್ರಮಗಳಿಗೆ ಆಹ್ವಾನಿಸುತ್ತಾರೆ. ಜನ ಪ್ರತಿನಿಧಿ ಎಂಬ ನೆಲೆಯಲ್ಲಿ ಖಾದರ್‌ರವರು ದೇವಸ್ಥಾನ, ದೈವಸ್ಥಾನ, ಚರ್ಚು, ಮಸೀದಿ, ಉರೂಸ್, ಸುನ್ನಿ, ಎಪಿ, ಈಕೆ, ಸಲಫಿ, ಜಮಾತೆ ಇಸ್ಲಾಂ ಎಂಬ ಬೇಧ ಬಾವ ಇಲ್ಲದೆ ಭಾಗವಹಿಸುತ್ತಾರೆ. ಅವರವರ ನಂಬಿಕೆಗಳನ್ನು ಗೌರವಿಸುತ್ತಾರೆ. ಅಂತೆಯೇ ಕೆಲ ದಿನಗಳ ಹಿಂದೆ ತಮ್ಮ ಕ್ಷೇತ್ರದ ಕೊರಗಜ್ಜ ಕಾರ್ಯಕ್ರಮದಲ್ಲೂ ಭಾಗವಹಿಸಿದ್ದರು. ಪ್ರತೀ ವರ್ಷವೂ ಅವರು ಆಹ್ವಾನಿಸುತ್ತಾರೆ ಮತ್ತು ಖಾದರ್ ಭಾಗವಹಿಸಿತ್ತಾರೆ ಇದನ್ನೇ ನೆಪವಾಗಿಸಿಕೊಂಡು ಕೆಲವರು ವಿದೇಶದಿಂದ ಸಾಮಾಜಿಕ ಜಾಲತಾಣದ ಮೂಲಕ ನಿರಂತರ ಖಾದರ್‌ರವರನ್ನು ಅತ್ಯಂತ ಹೀನಾಯವಾಗಿ ಹಿಯ್ಯಾಳಿಸಲು ತೊಡಗುತ್ತಾರೆ. ಸಾಮಾಜಿಕ ಜಾಲತಾಣದಲ್ಲಿ ಸಕ್ರಿಯರಾಗಿರುವವರು ಅದನ್ನು ಗಮನಿಸಿರಬಹುದು. ಖಾದರ್‌ರವರನ್ನು ಹಿಯ್ಯಾಳಿಸಲು ಅವರು ಬಳಸುತ್ತಿದ್ದ ಶಬ್ದ ಮತ್ತು ಭಾಷೆ ಯಾರನ್ನೂ ಒಮ್ಮೆ ರೊಚ್ಚಿಗೆಬ್ಬಿಸುವಷ್ಟು ಕೆಟ್ಟದ್ದಾಗಿರುತಿತ್ತು. ಅದಕ್ಕೆ ಪ್ರತಿಕ್ರಿಯೆಯಾಗಿ ಬರುತ್ತಿದ್ದ ಬರಹಗಳೂ ಅಷ್ಟೇ ಪ್ರಚೋದನಾತ್ಮಕ ವಾಗಿರಿತ್ತಿತ್ತು.
ಈ ಎಲ್ಲಾ ವಿಚಾರವನ್ನು ಉಲ್ಲೇಖಿಸುತ್ತಾ, ಅವರಿಗೇ ಸಂಬಂಧಿಸಿ ಉರೂಸ್ ಸಮಾರಂಭದ ವೇದಿಕೆಯಲ್ಲಿ ಖಾದರ್‌ರವರು... "ಊರಲ್ಲಿ ಮೋಸಮಾಡಿ ವಿದೇಶಕ್ಕೆ ಹೋಗಿ ಕುಳಿತು ನನಗೆ ಬುದ್ದಿ ಹೇಳುತ್ತಿದ್ದಾರೆ. ನಾನು ಎಲ್ಲಾ ಕಡೆ ಹೋಗಿದ್ದೇನೆ, ಹೋಗುತ್ತೇನೆ .. ನಾನು ತಪ್ಪಿದರೆ ನನ್ನನ್ನು ತಿದ್ದಲು ಉಲೆಮಾಗಳಿದ್ದಾರೆ. ಈ ಲೋಫರ್ ಗಳಿಂದ ನಾನು ಪಾಠ ಕಲಿಯುವ ಅಗತ್ಯವಿಲ್ಲ...." ಎಂದು
ಹೇಳಿದ್ದಾರೆ.
ಈ ವಿಡಿಯೋದ ತುಣುಕನ್ನು ವೈರಲ್ ಮಾಡಿ ವಿದೇಶದಲ್ಲಿರುವ ಎಲ್ಲಾ ಪ್ರವಾಸಿಗಳನ್ನು ಖಾದರ್ ಅವಮಾನ ಮಾಡಿದ್ದಾರೆ ಎಂದು ಬಿಂಬಿಸಲು ಪ್ರಯತ್ನಿಸುತ್ತಿರುವುದನ್ನು ನಾವು ಕಾಣುತ್ತಿದ್ದೇವೆ. ಈಗಲು ಕೆಲವರು ಖಾದರ್ ವಿರುಧ್ಧದ ತಮ್ಮ ಬರಹ ಹಾಗೂ ವಾಯ್ಸ್ ಮೆಸ್ಸೇಜುಗಳಲ್ಲಿ ತೀರಾ ಕೆಟ್ಟ ಶಬ್ಧ ಭಾಷೆ ಬಳಸುತ್ತಿದ್ದಾರೆ. ಸಾಮಾಜಿಕ ಜಾಲತಾಣಗಳಲ್ಲಿ ಸಾರ್ವಜನಿಕ ಮರ್ಯಾದೆಯನ್ನು ಮೀರಿ ನಡೆಯುತ್ತಿರು ಖಾದರ್ ಪರ ವಿರೋಧ ಚರ್ಚೆಗಳು ಸಮುದಾಯದ ಮಾನ ಹರಾಜು ಹಾಕುತ್ತಿದೆ ಇದು ಇಲ್ಲಿಗೇ ನಿಲ್ಲಲಿ ಎಂಬುದು ಎಲ್ಲಾ ಪ್ರಜ್ಞಾವಂತ ಮುಸ್ಲಿಮರ ಅಪೇಕ್ಷೆ.
UTK has insulted innocent loafers by calling communal goons as loafers
Mr. U T Khader,
Please do not twist your statement. You clearly made a statement " Dongi maadi gulfge hodavaru". Even i was a huge admirer of you till date for your simple nature and work which you have done during your tenure as a minister and MLA. But that one statement has made a big difference. I watched the video 2 to 3 times to check about the background. You were referring to a group which conducts meeting in hills(gudde) under torch light. But hope you remember that same group was in your favor when you first contested for bye-election after your father's demise. My request is not to have over confidence, which may result in ego and ultimately result in losing. So many egoistic emperors in the world have lost their empire and power. Therefore, you are not a match at all. If you want to condemn a particular group or party, name it and condemn it in specific & do not make generalized statement. Your statement of "DONGI MAADI GULFGE HOGIDDU" has hurt the sentiments of NRI community who have come here away from their families to earn a livelihood.
Kindly take your time to tender an apology for your words. May Almighty Allah bless you with good health and strength to serve the society and community in a better way.
I think in this state election only one thing will happen for sure "Ibbara Jagala Muraneyavanige Laaba"...
Last year Sangh Parivar leaders were hurt when UT Khader said those who oppose constitution should be hit with slipper. This clearly proved that they oppose constitution. Now some SDPI leaders are hurt when UT Khader said that he wants to learn lesson from Ulema and not from loafer or a person who avoids work and spends time doing useless things. This also proved who are loafers.
“Loafer” is not an abusive or derogatory word. “Communal” is more abusive and insulting word compared to “Loafer”.
Election won't decide anyone's fate. Fate will be decided by the Creator. Our prayers are with self-less politicans like UT Khader.
Feel very sad to see some fringe groups unnecessarily pulling the legs of an honest politician in the name of religion. When I embraced Islam several years ago Muslims used to spend time by fighting each other on religious matters and absurd rituals like Urus, Maulid, ratheeb etc. Now Muslims are fighting with each other by forming political parties. When these Muslims will learn lessons? When they realise their responsibilities? When they stop petty politics?
First of all loafer is not an abusive word. It just means an idle person or a ‘poli huduga’ in Kannada. But the uneducated loafers do not know the meaning of loafer i think. That’s why they making it a big issue.
Dikkara ninage Mr Khader
Bara barutha raayara kudure katthe yaayithu.....
Khader bhai... muslim community had very good hope on you & supported you on full extent... But you are going towards normal politician behind money & seat.... SUPPORT doesnt mean that only to muslims... A true leader will treat all community fair & equally... which congress & other party leaders couldnt do... Instead you are blaming our muslim brothers without having basic knowledge.... Politician doesnt understand normal person way of living that how they spend daily life & how much efforts they are taking to fulfill their family needs...
In sha allah your fate will be decided in this election..
Let the Election results tell who are loafers and cheaters In sha Allah.
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