Transcript How Can Airborne Transmission of COVID-19 Indoors be Minimized What We Know Now final https://www.youtube.com/watch?v=DpWNnNuxFYE 00:00 hello everyone and thank you for joining 00:02 us my name is amanda cramer and i am the 00:04 alumni engagement program manager at the 00:06 university of colorado boulder's 00:08 leeds school of business welcome back to 00:11 our fifth 00:11 covid19 webinar series these are 00:14 certainly trying times and here at cu 00:16 boulder 00:17 we have gathered our world-renowned 00:18 faculty to provide frank and timely 00:21 insights 00:22 for life during the covid19 pandemic 00:24 today 00:25 is the first of four webinars in this 00:27 covid19 related webinar series 00:30 to view upcoming webinars please visit 00:32 our website at colorado.edu 00:34 business alumni click the drop down 00:37 arrow and click attend online webinars 00:39 for today's webinar we're so excited to 00:42 welcome professor in the department of 00:43 chemistry and biochemistry 00:45 and fellow of the cooperative institute 00:47 for research in the environmental 00:49 sciences 00:50 dr jose jimenez here presenting on 00:53 the modes of transmission of covid19 and 00:55 how to protect ourselves 00:57 what we know now a few housekeeping 01:00 items before we begin 01:02 first if you have any questions now or 01:03 during the presentation that you would 01:05 like to ask jose 01:06 please send a question through the q and 01:08 a interface 01:10 we will monitor questions as they are 01:11 submitted and jose will respond to them 01:14 at the end of the presentation 01:16 as a reminder for optimum audio quality 01:18 we do have everyone on mute except for 01:20 myself 01:21 and our speaker if you experience any 01:23 technical difficulties during the 01:25 webinar please notify us 01:27 through the chat interface and one of 01:28 our support specialists will touch base 01:31 lastly a link to access the webinar 01:33 recording will be sent to all 01:34 registrants tomorrow along with a survey 01:36 link and supplemental resources from 01:38 today's presentation 01:40 now i'm excited to introduce today's 01:42 speaker a professor in the department of 01:44 chemistry and biochemistry 01:46 dr jose jimenez specializes in 01:48 atmospheric 01:49 chemistry field measurements aerosol 01:51 mass 01:52 spectrometry and advanced instrument 01:54 development 01:55 he holds a phd from the massachusetts 01:58 institute of technology 01:59 and amongst many accolades he is the 02:01 fifth most cited scientist worldwide in 02:04 the geosciences 02:06 welcome jose and thank you so much for 02:07 being here i'm going to hand the webinar 02:09 over to you now thank you very much 02:11 amanda and 02:12 thanks for having me um okay so 02:16 um hopefully everyone can see my screen 02:18 and can um 02:19 hear my voice um so i'm gonna talk about 02:22 the most of transmission of 02:24 sarskof2 which is the virus that causes 02:26 kobe 19 02:27 and how to protect ourselves and i know 02:30 many of you attended the seminar by my 02:32 colleague shelly miller 02:33 a couple of months ago so then hopefully 02:35 this will be an update 02:37 with some of what we have learned since 02:38 then for you um 02:40 if you want more information i would 02:42 highly recommend this link at the end 02:44 tinyurl.com 02:46 frequently asked questions that thank 02:47 you so basically everything 02:50 i'm gonna say is there with an 02:51 explanation and then 02:53 um i have some other links there as well 02:57 and this is the outline that will i will 02:59 keep coming back to first i will explain 03:02 kind of from a scientific point of view 03:03 but it's still um 03:05 uh briefly how can the values be 03:07 transmitted 03:08 then i will go on to uh summarize some 03:11 evidence that we think that the aerosol 03:13 transmission is actually major or 03:15 probably dominant 03:16 uh i'll briefly um talk about why the 03:19 cdc and who 03:21 are so wrong on this on this topic sorry 03:24 to have to say this but that's the case 03:26 and why they are so slow to accept it 03:29 and then 03:30 um we will go on to what i think most 03:32 people are interested in which is how 03:34 can we protect ourselves and how to 03:36 think uh 03:37 about this and it's uh there is a lot of 03:40 things that we can do but we need to 03:41 smart about 03:42 we need to be smart about it okay and 03:44 then we'll go on to 03:45 two questions so without further ado let 03:49 me 03:49 go on to the ways in which the virus can 03:51 be transmitted 03:52 okay um but we 03:56 before that we need to think a little 03:57 bit about the size of the virus 04:00 and um so viruses and you have here 04:03 a number of them they can vary in size 04:05 this particular virus is about a tenth 04:07 of a micro 04:07 microbe is a millionth of a meter right 04:09 and you've seen this picture many times 04:11 so for scale if this is the diameter of 04:13 a human hair which is 80 microns the 04:15 virus is this little dot over here 04:18 and it's probably smaller but if i made 04:19 the smaller you couldn't see it okay 04:22 and um we often talk about pollution 04:24 like all this 04:25 all this uh smoke from the fires which 04:27 is not actually not that different from 04:28 the virus size 04:30 and then we also talk about this other 04:31 pn 2.5 pm10 which is 04:33 a larger particles or a grain of sand 04:36 would be 04:37 like 19 microns so this this gives you 04:38 an idea of scale 04:40 uh for these different business 04:44 particles right and one thing that's a 04:47 very serious problem in communicating 04:49 about this is is that there is a lot of 04:51 misconceptions 04:52 about the particles on which the virus 04:55 is present 04:56 come a lot of people talk 04:59 as if the virus basically pass alone in 05:01 the air 05:02 maybe with a little bit of water when it 05:04 comes out of us but then the water 05:05 evaporates and you just have the virus 05:07 floating alone 05:08 um this is wrong okay and 05:12 even though it's featured this picture 05:14 is actually from the journal of the 05:15 american medical association 05:16 and it's just wrong okay that's not 05:19 what's going on 05:20 uh what's going on is more something 05:22 like this or what's what we think is 05:24 important is that you have 05:25 particles that are much bigger that are 05:27 for example coming out of my mouth as i 05:29 speak 05:30 uh because there may be made when i say 05:32 the t or something like that some little 05:34 particles come out 05:35 or they are also maybe my vocal cords 05:37 and they have a few viruses sprinkled in 05:39 but most of the particle is water and 05:41 neither saliva or mucin 05:43 which is basically what lines up a 05:45 respiratory tract okay 05:47 so well this is important from a 05:49 practical point of view because we're 05:51 not trying to defend ourselves 05:52 against tiny particles that are 05:54 difficult to filter but we're trying to 05:56 define ourselves against a bigger chunk 05:58 of material that are actually a little 05:59 easier 06:00 okay um okay so now that we have 06:03 explained this um 06:08 we're gonna talk about the three modes 06:09 of transmission which are 06:11 um so everyone agrees that basically we 06:13 can get these virus or 06:14 other respiratory viruses in three ways 06:16 what we call droplets 06:18 aerosols and surfaces right uh sometimes 06:21 people use different 06:22 different names for for these things but 06:25 i'm gonna 06:25 these are the ones i i'm gonna use you 06:27 may hear formites 06:29 to talk about surfaces so you may use 06:31 you may hear 06:32 you know droplet nuclei or small 06:34 droplets you talk about aerosols i'll 06:36 just use these terms 06:37 droplets are basically ballistic 06:40 projectiles 06:41 okay when i'm talking you know there can 06:43 be some projectile big enough that comes 06:45 in and lands in my monitor right is the 06:47 the best analogy is this angry birds 06:49 game 06:50 you know they they come in and if you 06:52 have a parapet they kind of stop it and 06:54 otherwise 06:55 if they hit you on the eyes on the 06:58 nostrils or in the mouth 06:59 and they carry the virus then from then 07:01 they can initiate infection 07:04 these larger ballistic droplets is is 07:06 what cdc and who says 07:09 is dominating infection okay this is 07:11 wrong 07:12 i i i and many other scientists are 07:16 sure this is wrong okay and these 07:18 droplets really are only major 07:20 for situations when someone is coughing 07:22 or sneezing 07:23 so if someone comes or sneezes towards 07:26 you 07:26 and they basically score a direct hit on 07:28 your eyes then 07:30 you have a lot of probabilities are 07:32 infected of getting the infection that's 07:34 clear but when we are talking 07:36 that they are much less important than 07:38 they thought and as i will say later 07:40 anthony fauci has basically accepted as 07:42 much um 07:45 the other souls are different they're 07:46 like smoke they're not projectiles 07:48 you know they're like like when someone 07:50 is smoking or vaping and they're coming 07:51 out of your of your nose 07:53 and your mouth and they they don't fall 07:55 to the ground they stay in the air and 07:56 they dilute right 07:58 and exactly how they behave depends on 08:00 what's going on if you're outdoors and 08:02 it's windy they go away very quickly 08:04 if you're in a closed room that has low 08:05 ventilation they will build up 08:07 right and build up and build up and get 08:09 thicker and thicker smoke over time 08:10 right 08:11 and this is the way to think about 08:12 aerosols and this is the key if you 08:14 remember one thing from this 08:15 presentation remember 08:17 um they are like a smoke if i'm worried 08:20 about the smoke 08:21 that other people are smoking in this 08:22 situation what would i do 08:24 that's the most important thing and then 08:28 there is transmission through the 08:29 surfaces and early on they told us we 08:31 have to wash our hands all the time and 08:32 all that 08:33 but it's clear now i think to everybody 08:35 that 08:36 transmission through surfaces it's it 08:39 happens 08:40 but it's not major so we need to keep 08:43 washing our hands and all that 08:44 but that's not the major way in which 08:46 the virus is transmitted okay 08:48 and uh and we have to spend much more 08:50 time thinking about the air than we than 08:52 we should spend thinking about surfaces 08:57 so now some more technical illustration 09:00 here you have you know 09:01 the ballistic drop reaching a person in 09:04 the eye and then other sorts of 09:05 different sizes that do different things 09:07 maybe i'll skip more details here 09:08 because 09:09 probably too much for this audience okay 09:12 so 09:13 i'm making uh this strong statement that 09:16 i think 09:16 uh transmission through our results uh 09:18 is major or dominant and that cdc and 09:20 that lecture is wrong 09:21 so i'd like to at least support this um 09:23 a little bit 09:24 uh since people would be understandably 09:26 skeptical 09:27 uh so we're working on a publication 09:29 with many other scientists 09:31 about summarizing the evidence okay and 09:33 these are different lines of evidence 09:35 that can tell you something about which 09:36 route may be 09:37 major or less major and here we have for 09:40 droplets and 09:41 formites which is surfaces and narrow 09:44 cells right 09:45 and a green check mark or two means 09:47 there is evidence or there is a lot of 09:48 evidence 09:49 and an x a black x means there is no 09:52 evidence and a red x means actually 09:53 there is evidence against 09:55 okay and there is many reasons what you 09:57 see here is the balance of the evidences 09:59 aerosols have many 10:01 um lines of evidence that support them 10:03 surfaces have some 10:04 droplets have few and actually have a 10:06 strong evidence against 10:08 okay and really the recommendations from 10:10 cdc and double h 10:11 are backwards they say this is important 10:13 that has no evidence this is less 10:14 important 10:15 have some evidence this is not important 10:17 which is really what has the most 10:19 evidence 10:19 let me give you a couple of examples 10:21 okay so for example we see 10:23 that when we go outdoors it is much much 10:25 less likely to get the vcs 10:27 this doesn't depend on what you believe 10:28 is just an empirical observation right 10:30 there is a database of super spending 10:32 events there is more than a thousand 10:34 events 10:34 and there is one outdoors and more than 10:36 a thousand indoors and 10:38 many other data sets that say the same 10:40 thing right this is very easy to explain 10:42 with aerosols because 10:43 the you know this smoke that's coming 10:45 out of us we will get dilute much more 10:47 outdoors there is always a little more 10:49 there's always quite a bit more wind 10:50 outdoors than indoors 10:52 even if we don't feel it very much and 10:53 also aerosols rise 10:55 because the air that we breathe is warm 10:57 and it rises 10:59 in a room the ceiling is going to catch 11:00 it and they're going to bring it back to 11:01 us 11:02 but outdoors it doesn't and it gets 11:04 diluted much more right 11:06 so this is easy to explain with 11:07 ourselves and 11:09 i i have yet to find someone who even 11:11 bothers to offer an explanation 11:14 of how holistic droplets could explain 11:15 this observation okay 11:17 another one is super spelling events you 11:19 know we have written a paper with 11:21 professor miller about the choir case in 11:23 in washington and they're very easy to 11:25 explain with other souls and they're 11:27 basically 11:28 certainly in the case of the queen 11:29 they're impossible to explain in any 11:31 other way 11:32 and you have seen the cases of the the 11:33 bus and the restaurant those are from 11:35 scientists that we are working with 11:37 and there is just a lot of events and 11:40 they are easy to explain with ourselves 11:42 not possible with the other routes and 11:44 there is many other 11:45 lines of evidence that i could explain 11:47 spend the whole hour talking about but 11:49 but i want because that's not what you 11:51 are interested in 11:52 for the most part um 11:56 but uh there are a lot of myths so you 11:58 will hear people 11:59 uh talking to the press scientists who 12:01 don't believe in aerosols and they will 12:02 say things like 12:03 well if it's an aerosol it has to be 12:05 like missiles or it has to infect at 12:07 long range or you know 12:08 and this is this is all wrong okay this 12:11 is all 12:12 all wrong and and there is um i will 12:14 leave the amanda the slides and she will 12:16 post them 12:17 um and in there you have a link to 12:21 a document i wrote which explains why 12:22 these are wrong again i don't have time 12:24 to 12:25 to go into that um so let's 12:28 um go a little bit more about the 12:32 the core of of of this of this issue 12:36 this is what we have been told by who 12:38 and cdc that this is why social distance 12:40 helps 12:41 okay they tell us that there are these 12:43 ballistic droplets that are coming out 12:44 of us and this is from a who video where 12:46 you see the droplets coming out of the 12:48 person 12:49 and then when they are close it hits the 12:51 other person 12:52 and when they're far they just land on 12:54 the surfaces right 12:55 and this is this is i mean 12:59 we know independent of what you believe 13:01 about the road to transmission we know 13:02 and we have known for more than a 13:04 century 13:05 that keeping your distance helps with 13:07 respiratory diseases 13:08 right it helps reduce transmission and 13:11 this is how they interpret it 13:12 and we we think mostly this is incorrect 13:14 the reason why it helps 13:16 is um 13:19 the reason why it helps is because um it 13:22 reduces the concentration of these 13:24 aerosols that you breathe okay 13:26 so this person is is breathing out this 13:28 respiratory particles all the time 13:30 smoke is an aerosol and it's just is use 13:32 useful because it lets us see it 13:34 okay and then these other particles are 13:36 too too few 13:37 to see right but what you see you know 13:40 is that the smoke is always most 13:41 concentrated right here if you are 13:42 talking to this person 13:44 right there you will be breathing a lot 13:46 of their exhale breath with little 13:47 dilution and if there is virus here you 13:49 will breathe a lot of virus right 13:51 that is why keeping your distance 13:53 reduces transmission to the most part 13:55 right 13:56 but um then if uh if you're in a room 14:00 that has low ventilation 14:01 you are not safe right because yeah you 14:03 are not in front of the person that's 14:05 smoking or something like that but over 14:06 time 14:07 the smoke meaning the virus will build 14:09 up and will build up and use if you 14:11 spend a lot of time 14:13 then you can get then you can get 14:15 infected okay 14:16 if the droplets were right you could get 14:19 infected in this situation but not in 14:21 that one 14:21 what we see is that you can get infected 14:23 in both situations these are all the 14:25 super spelling events 14:26 and that actually is quantitatively 14:28 consistent when we see one or the other 14:29 second it's evidence for 14:31 for irresolves and not droplets 14:35 okay so now i'm gonna switch 14:38 briefly to why are cdc and which are so 14:41 wrong 14:41 and so slow to accept this okay and 14:44 again i could talk for hours about this 14:45 but i'll give you a very brief version 14:48 so we can look at the for example the 14:51 latest uh scientific brief of who where 14:53 they talk about these things 14:55 and they tell us that respiratory 14:56 droplets are larger than five to ten 14:58 microns in diameters 15:00 whereas um uh 15:03 particles that are smaller than five 15:04 microns we call the myosins right 15:07 and then they go on to describe 15:08 basically how this transmission which is 15:11 they said so they're saying you know 15:12 if they're larger than five to ten 15:14 microns then they're gonna fall to the 15:16 ground and either they hit you in the 15:17 eye or in the mouth or they fall to the 15:19 ground right and if they're smaller than 15:21 five microns then they float in the air 15:23 is this correct right this is the world 15:24 health organization you will think they 15:26 have good experts right 15:28 uh well this is totally wrong this is 15:30 actually from the cdc webpage they have 15:32 an aerosols 101 tutorial 15:35 on the occupational medicine branch not 15:37 the infectious disease branch 15:40 about particle settling in steel air so 15:43 basically what you need to look at here 15:44 is five microns which is in between 15:46 here so 10 microns will settle in eight 15:49 minutes to extend 15:50 it takes eight minutes to fall to the 15:52 ground well three microns takes more 15:54 than an hour 15:55 for five microns which is in between it 15:57 takes half an hour 15:58 right and really to fall to the ground 16:01 um 16:02 in within one to two meters you're 16:04 talking about things that are much 16:05 larger 16:06 100 microns and remember we said that 16:07 human hair is 80 microns so you're 16:10 talking about much much much larger 16:11 particles in order for them to fall to 16:13 the ground 16:15 um this this is wrong and it has been 16:17 wrong for 16:18 at least three decades and i'm actually 16:19 working with historians we're close to 16:21 submitting a paper 16:22 explaining why they got it wrong i 16:25 cannot tell you 16:26 today but we should be able to tell you 16:28 very soon 16:31 but basically something what's more 16:32 important is dr fauci admitted this 16:34 error a few days ago 16:36 so this is you can see the video here in 16:38 the harbor he gave a talk 16:40 and basically he says you know this was 16:43 just totally wrong and 16:44 he learned this from us came right there 16:46 and the meltdowns were working with a 16:47 group 16:48 approach him and talked to him and and 16:50 he understood that 16:51 that this was wrong you know and that 16:53 cbc is wrong and the rule is wrong 16:55 if it has yet to lead to a change 16:58 on the guidelines but hopefully it's a 17:00 first step 17:02 but uh if you use this thing fauci said 17:04 this is these are his words bottom line 17:06 is there is much more error so than we 17:07 thought 17:08 and the consequence is that if there is 17:10 much more aerosol there is also 17:12 many fewer droplets okay 17:16 and uh let's see 17:20 and i'm gonna skip over this remember 17:22 that 17:23 yeah just uh just to save time 17:27 um so how did we end up here how come 17:30 that we ended up in a situation in which 17:34 the who and the cdc are so wrong 17:36 right this is pretty shocking and indeed 17:38 is shocking and 17:39 you know and um took me a while to even 17:42 just realize how wrong it was but but it 17:45 is and 17:46 and there is no you know often people 17:48 online say oh there is some conspiracy 17:50 and they knew and they hid it and it's 17:53 not that i've talked to a lot of people 17:55 on the whole and high level people in 17:57 different places and 17:59 it is not a conspiracy of any kind they 18:01 are genuinely 18:02 scientifically wrong and confused and 18:04 there is a reason why that is 18:07 um and we have to go back 150 years or 18:11 160 years to understand this in easter 18:14 right 18:14 so before you know in the 1800s and 18:16 before we had this theory of miasmas 18:19 which meant that disease came through 18:20 the air and you know there was this 18:22 bad air that could come and bring bring 18:24 disease to you and this was very scary 18:25 and 18:26 and you couldn't defend yourself against 18:28 right uh 18:29 in the decade of the 1860s pasteur in 18:32 france discovers germs 18:34 and he realizes that and demonstrates 18:36 that 18:37 um for an infectious disease to go from 18:40 person a to person b 18:42 the germ has to go from person a to 18:43 person b either through the air 18:46 or through the water or through your 18:48 hands or through food 18:49 some one way or another it has to find 18:51 its way through the physical world from 18:53 one person to the other right 18:55 and then people with arm with that 18:57 knowledge start to investigate okay for 18:58 cholera it goes 18:59 this way for uh the flu it goes away and 19:02 the evidence accumulates 19:04 and you know but there are competing 19:06 theories and there is no theory that's 19:07 well established 19:10 and in 1910 um charles chapin who 19:13 was a president of the american public 19:15 health association 19:17 who had been very successful um 19:20 preventing basically transmission and 19:22 close proximity basically he 19:24 he was the one who conceptualized social 19:26 distance and showed that it worked 19:27 so he wrote a book that called the 19:29 sources and modes of infection which you 19:31 can find online and highly recommend 19:32 very interesting book 19:34 um and um and basically he 19:38 so he had said that close proxy he had 19:40 realized that close proximity work and 19:42 he had been very successful 19:43 in hospital in providence that he he 19:46 created 19:47 showing that that he could really reduce 19:49 infection a lot by keeping the distance 19:51 right 19:52 um and then so then but the question was 19:54 why 19:55 right and he he tries to explain in this 19:57 book why and 19:58 then there was a german scientist fluger 20:00 who had measured this droplets he had 20:02 put some 20:03 plates of agar in the floor and then 20:05 then someone was talking and then they 20:06 realized that they 20:07 these droplets seem to fall within one 20:09 to two meters right 20:11 um and they couldn't measure aerosols 20:13 yet right 20:14 so then um japan has to take a position 20:17 in this book 20:18 and then basically he he hates this 20:20 myasma theory that was still in the 20:22 public consciousness 20:24 because he says pretty much directly if 20:26 people think 20:27 uh the disease comes through the air you 20:29 cannot get them to wash their hands and 20:30 to keep their distance right 20:32 and he realized that that washing their 20:34 hands and keeping their distance did 20:35 help so to emphasize that 20:37 he says without evidence 20:40 he says that the infections in close 20:42 proximity is due to droplets 20:44 and also transmission is nearly 20:46 impossible and 20:48 this is wrong but that's what he said 20:50 and that becomes that comes at the time 20:52 in which the 20:53 you know epidemiology and infectious 20:54 diseases was ready 20:56 for a new paradigm perhaps and is very 20:58 successful and becomes a paradigm 21:00 becomes really a dogma that is 21:02 extends all the way to the who and the 21:04 cdc today that's what they believe 21:07 they don't even remember why they 21:08 believe it in many cases but that's what 21:10 they've been told 21:11 for a century and that's what they think 21:13 is going on these droplets cause 21:14 infection and many people are shocked 21:17 when we challenge that 21:18 that uh that dogma okay 21:21 um and they because they come from this 21:26 from this paradigm in which aerosol 21:27 transmission is nearly impossible they 21:29 also ask for 21:30 unbelievable levels of evidence um 21:33 for aerosols you know i'll show you 21:35 earlier how it is shocking 21:37 that there is almost no evidence for 21:39 droplets but they are taken for granted 21:40 and cvc tells us this is the major model 21:42 transmission and there is a ton of 21:44 evidence for ourselves but is never 21:46 enough they always tell us well this is 21:47 never enough 21:48 we don't know if we still don't know 21:49 these details are detailed and that's 21:50 used 21:51 it's usually reflective of the bias from 21:53 which which 21:54 in which their minds are framed um 21:58 but we are not the first by a long shot 21:59 to to point this out already in 1930s 22:02 wells and riley 22:03 and others start to to say no no wait 22:07 this is an error 22:08 um you can transmit respiratory this is 22:10 stupid 22:11 um but they find very few 22:14 verified first resistance okay and there 22:17 is only 22:18 a few diseases like missiles chickenpox 22:20 and tuberculosis 22:21 which were described as droplet from my 22:24 diseases droplet surface diseases for 22:26 many decades and there are many papers 22:27 where they 22:28 they describe them that way and they 22:30 were you know for tuberculosis 22:32 they say well it's a droplet for my 22:34 disease but then there is all these 22:35 outbreaks in bars and in fully 22:37 ventilated rooms 22:38 and in factories and in ships you know 22:41 that we cannot explain and it's the same 22:43 for me so 22:43 missiles the same for chickenpox the 22:45 same that we're hearing now right there 22:47 is all these 22:48 all these outbreaks like the restaurant 22:49 there were outbreaks in choirs for 22:51 tuberculosis it's very much the same 22:53 story 22:54 but uh eventually these diseases are 22:57 more contagious and through 22:58 basically a century of work they're 23:00 demonstrated and finally accepted right 23:02 that um that these diseases go through 23:06 the air but these are basically the only 23:07 ones that have been accepted 23:09 so then we end up with a situation now 23:11 in which 23:12 a lot of people confuse you know the 23:14 fact that only very contagious diseases 23:16 have been accepted 23:17 which is an artifact of history with a 23:19 law of nature 23:20 they tell us that no no if kobe 19 23:24 went through the air it would be highly 23:25 contagious and everyone on earth would 23:26 have gotten injured which makes no sense 23:28 whatsoever there is no reason that 23:29 nature 23:30 only makes ultra contiguous serious 23:32 diseases you know 23:34 there is actually all kinds of levels of 23:35 contagiousness it just hasn't been 23:37 accepted right 23:41 so a little more about how we ended up 23:43 here 23:44 um you know so we end up in a situation 23:47 you know before kobe 19 aerosols have 23:48 never been considered important for 23:50 disease transmission they have accepted 23:52 missiles and chicken pox but basically 23:53 there are very few diseases like that 23:55 people are pretty sure there are no more 23:56 diseases like that so 23:58 the people who work on this medical 24:00 infectious diseases and epidemiology 24:02 don't know much about eras also know 24:04 very very little about their resource 24:05 and they make huge errors like the five 24:07 micron error 24:08 i told you earlier that fauci has now 24:11 admitted 24:12 you know and these leads for example who 24:14 convinced all these committees 24:16 to study kobe 19 there is no one there 24:18 who knows about the resources right then 24:19 this is 24:20 uh a tweet from someone who has worked 24:22 very closely with who did a major study 24:25 with masks and he says you know i'm yet 24:27 to have a meeting or even a single email 24:30 with who that includes a singular as a 24:32 scientist 24:33 so basically you have a lot of people 24:35 who are deciding that the results are 24:36 not important 24:37 nobody in the room understands aerosols 24:39 you know you know and the and the key 24:41 committee that has decided that is not 24:43 aerosols 24:44 is dominated by hand washing experts 24:47 right those are the people that that 24:49 um were called in by who to make their 24:51 committees so 24:52 miraculously the first thing they 24:54 recommended i was accompanying 24:56 was lots of hand washing you know we all 24:57 had to wash your hands it's a good idea 24:59 it can be transmitted that way 25:01 it's just a minor pathway right you know 25:03 like 16 25:04 under the study in the uk and these 25:07 people in the community have published a 25:08 paper about resources and it's just full 25:09 of errors and misconceptions 25:12 i don't think i found anything correct 25:14 you know and this is the key committee 25:16 that's deciding the most of transmission 25:18 and so this is really a bad situation 25:20 wherein yeah 25:22 but for now we're on our own until i 25:24 mean we don't know if this admission by 25:25 fauci 25:27 um it's gonna change things but for now 25:29 we're on around the 25:30 world organization said no this is from 25:32 march that 25:34 it's not in the air doesn't transmit 25:36 through they are you know so what we 25:37 encounter over an hour you know you have 25:39 people like me who say no no i'm 25:41 you know i'm a prestigious scientist i i 25:43 disagree but people are like well 25:46 why doesn't the cdc say this why doesn't 25:48 that be a choice like that and this is 25:50 from one one of our former students who 25:52 is now a professor in texas and he was 25:53 saying you know 25:54 i've consulted with many businesses who 25:56 were interested but at the end nobody 25:57 has done anything 25:59 because everybody on cdc don't 26:02 say this is not important and 26:03 unfortunately that's the case if you are 26:05 here in the seminar hopefully 26:07 i'll convince you that this is actually 26:10 some good chance that they may be wrong 26:12 and it's not so hard to protect yourself 26:14 you may as well protect yourself right 26:16 that's that's 26:17 i think what we can hope for until they 26:19 change the islands 26:21 okay so without further ado let's talk 26:23 about what we can do to protect 26:26 ourselves 26:26 and to protect others 26:30 and again if you join late um this link 26:34 at the end tinyurl.com 26:36 frequently asked questions faq iriso has 26:39 everything i'm gonna say 26:40 and and more 26:44 okay so to prevent transmission um 26:48 basically we have to keep doing 26:50 everything they've told us okay we have 26:52 to keep uh washing our hands we have to 26:53 keep wearing a mask 26:55 we have to keep the social distance the 26:57 reasons why some of these things work 26:59 are not the ones that we have been told 27:00 but we still have to do those things and 27:02 we have in fact we have to do them 27:03 better 27:04 than we have been doing them okay but 27:06 there is there is more okay which 27:08 has been discussed but it hasn't been 27:09 explained so therefore it is not uh 27:11 not followed very much okay so then 27:15 the silver bullet or the almost silver 27:17 bullet outdoors 27:19 okay uh if you are outdoors 27:22 distance and with a mask you know 27:25 it's almost completely safe i'll be i'll 27:27 be totally shocked 27:28 that people get uh infected in that 27:30 situation right 27:32 i mean i brought that 12 feet if you're 27:34 at six feet it's probably also okay 27:36 right 27:37 but uh that so so if you want to be safe 27:39 do things outdoors 27:40 especially high risk things like singing 27:43 or 27:44 or things like that okay um 27:48 and people say well it's very difficult 27:50 to do things outdoors it's going to be 27:51 cold well everyone 27:53 there's been articles from new york 27:54 times and yesterday there was one the 27:56 washington post about how 27:58 in 1910 and 1918 during 28:01 you know epidemics of tuberculosis or 28:03 the spanish flu 28:04 um a school was held outdoors you know 28:06 in in new york 28:08 and in boston in places where it's very 28:10 cold and actually the kids 28:12 um the kids did better being outdoors 28:15 and they 28:16 being indoors and so this is definitely 28:19 doable in colorado and in many places a 28:21 lot of the year so 28:22 basically if you again if you learn one 28:24 thing 28:25 do everything outdoors you go to a 28:28 restaurant 28:29 go to the never indoors go outdoors and 28:31 keep keep your distance and 28:33 you know where your mask and all that 28:36 so going back to here but we we can't 28:39 avoid going indoors right we need to go 28:41 to the 28:42 supermarket or to work or to school or 28:44 whatever 28:45 and not everyone is willing or able to 28:48 do things outdoors 28:50 so then we have a number of things you 28:52 have to avoid and these are 28:54 they can be understood in two ways you 28:56 can think of 28:57 every single one of them as you want to 28:59 breathe other 29:00 and other people may be breathing out 29:02 smoke which is a 29:04 an analog for the virus containing our 29:07 soul and then this does floating around 29:09 and you can breathe in you want to 29:10 breathe as little as possible right 29:12 you can also get this from a 29:14 mathematical model okay 29:15 and then the same conclusions come and 29:19 and we have an acronym or a mnemonic 29:21 which is this a civic duty 29:22 which uh i i wrote a 29:26 an op-ed in time magazine that you can 29:28 you will ximena's 29:30 time aerosols i'm assuming it will come 29:32 and you can read more about it but 29:34 basically the idea is you want to avoid 29:37 or reduce as much as possible 29:39 crowding indoors especially if there is 29:41 low ventilation 29:42 especially there is close proximity you 29:44 cannot keep the distance 29:45 it's a long duration if people don't 29:47 have masks or 29:48 people are talking or especially singing 29:50 and shouting right 29:52 the more you have of these things the 29:54 more intense 29:56 the higher the chance of transmission 29:58 yeah 29:59 of course this is so modulated by how 30:00 many infected people are in your region 30:03 right 30:03 if you're in a place that um one in a 30:06 thousand people 30:08 has the disease and may be contagious 30:09 right and you go to a gathering of ten 30:12 people 30:12 you have a one percent chance that 30:14 someone is infected right 30:16 if you go to a gathering of a thousand 30:17 people you are approaching 30:19 a hundred percent chance that someone is 30:21 infected in there right so 30:22 and if you are in a place where uh like 30:24 new york at the worst of the upgrade 30:26 probably 30:27 1 in 50 had uh had the disease and was 30:30 contiguous 30:32 on the population so then if you went to 30:33 gathering with 10 people 30:35 you had a 20 chance that someone was 30:37 infected right so how careful you have 30:38 to be depends on 30:40 the state of the vcs um you know that's 30:43 basically 30:44 what's the probability someone is 30:45 breathing out to smoke 30:47 where you are and then if that's 30:49 happening this is what you have to avoid 30:50 or you have to do the opposite uh to 30:53 reduce the 30:54 the chance of transmission so i'm gonna 30:56 give some some more details there are 30:58 um there are some posters that someone 31:00 someone made you know about this 31:03 all these actions which i uh 31:06 you know i'm not a graphic designer i 31:08 think i like this but 31:09 much better things could be done you 31:11 know if you guys um 31:12 any of you has um a creative streak you 31:15 know by all means 31:16 uh think about how we could communicate 31:18 this better 31:24 okay so then to try to emphasize that 31:26 endorse is just never totally safe okay 31:28 we can do things to really mitigate the 31:30 risk 31:32 but it's never totally safe okay so for 31:34 this we're gonna use the case of the 31:36 skagit choir so this is this is now the 31:38 for the paper that we have written 31:40 in the skagit choir about 80 some 31:42 percent of the people so 53 out of 61 31:46 or something like that got infected 31:48 right in the real event 31:49 now because we know that was dominated 31:51 by aerosols and because we 31:53 we understand and we have a mathematical 31:54 model of this we can say well what would 31:56 have happened if they had done this if 31:58 they had done that right 31:59 so let's do that let's let's run the the 32:02 choir 32:02 and change one thing at a time so let's 32:05 say now that it was a situation with low 32:06 ventilation that will increase the 32:08 ventilation right 32:09 uh to a larger you know four times as 32:11 much so then instead of you know 80 32:14 we go down to 50 transmission now let's 32:17 say no no we don't do anything with the 32:18 ventilation but we had an air cleaner 32:21 you know with a reasonable uh degree of 32:23 cleaning so again we go to 50 32:25 now we say that we are wearing good 32:27 masks okay but we are not 32:29 we're not ventilating that we're just 32:31 doing the choir with masks okay 32:33 we go again to 45 now let's say we don't 32:36 do any of these things but we just 32:37 shorten the rehearsal from two and a 32:39 half hours to half 32:40 to half as much an hour and 15 minutes 32:42 and again we go to 40 32:43 right so you see people ask me if i if i 32:46 go do this and i wear a mask am i safe 32:49 no there's no single thing that you do 32:51 that makes you safe 32:52 i mean the numbers may vary a little bit 32:54 but nothing is safe 32:57 nothing makes it safe alone right now if 33:00 you start to do many things 33:01 we call these layers of protection you 33:03 increase the ventilation 33:04 and you and you clean the air and you 33:06 wear masks and you shorten the duration 33:08 now you go from 80 percent 33:10 53 people getting sick to eight percent 33:13 five people getting sick 33:14 okay this was a pretty extreme event 33:16 that we're singing which greatly favors 33:18 the also getting into the air 33:20 but you see kind of this is what you 33:21 have to do 33:23 and um you know so you could ventilate 33:25 more you could open the windows you 33:26 could put fans in the windows you could 33:27 get and then this number will come down 33:29 but you know 33:30 it's never going to be zero now compare 33:32 where with the situation which we don't 33:33 do any of these things we just take the 33:35 choir and 33:35 both doors right and then you know i 33:38 mean 33:39 within the precision of the model nobody 33:41 gets it right 33:42 so again outdoors is is just preferable 33:45 to anything 33:47 that you can do indoors okay that said 33:49 outdoors is not magic you know if you're 33:51 outdoors and you're talking to someone 33:52 closely without a mask 33:53 you can get sick you need to be outdoors 33:55 distance and with a mass that's what's 33:57 safe 33:58 or in this case it's because they were 33:59 keeping where they would have enough 34:01 distance so that's what we are assuming 34:04 okay so then in this 34:08 frequently asked questions um page there 34:11 is 34:11 um there is this table uh that comes 34:13 from a paper published recently in the 34:15 british medical journal 34:16 about different situations right because 34:19 you can say well the choir but i'm gonna 34:21 go 34:21 do this other thing that's very 34:22 different right so then you have to 34:23 think about okay 34:24 is there a lot of people or there's few 34:27 people 34:28 is it outdoors or is indoors or is it in 34:30 indoors and fully ventilated are people 34:32 silent are they talking are they 34:33 shouting 34:34 are they wearing masks in a short time 34:36 or you know so basically 34:37 all these all these cases that i've told 34:39 you basically things that you have and 34:41 then 34:41 the color is the level of risk right so 34:43 you're silent 34:44 outdoors and there's few people and 34:47 you're wearing a mask 34:48 that's very safe if you're in a pool 34:50 ventilator place with a lot of people 34:52 and people are shouting you know you're 34:55 you're asking for it you know that's a 34:57 very dangerous situation 34:59 um this was you know people 35:02 this table is not perfect and we're 35:04 actually writing a paper trying to 35:05 improve it because some of the colors 35:07 but but i think 35:08 um to first order it does it can give uh 35:11 can give you some orientation 35:14 okay and i'm going to say in the 10 35:16 minutes i have before the questions i'm 35:18 going to say just a few more things 35:19 about some of the 35:20 important aspects which are basically 35:22 the masks 35:23 and the air cleaning and the ventilation 35:25 okay and 35:28 so first of all again a huge 35:31 misunderstanding 35:32 masks are not sieves a mask is not a 35:34 colander 35:35 you know people have this mental model 35:38 that 35:38 um you know these are like two fibers in 35:41 the mask and the particles have to 35:43 get stuck like if you were trying to 35:45 pass something to a colander that's not 35:47 how the physics works 35:48 okay masks work because particles 35:51 cannot take turns when the air goes 35:53 around these fibers and they 35:54 they hit it's called impaction or or 35:57 they touch 35:58 or you know very small particles are 36:00 kind of moving in brownian motion in the 36:02 air 36:03 and then they end up finding um 36:06 the fiber of the mask by diffusion or 36:08 also in the better mask in electrostatic 36:10 um in n95 or 36:13 surgical mass there is also an 36:15 electrical attraction 36:16 right and this is the reason why those 36:19 masks become less good over time is 36:20 because they lose this electrical 36:22 effect okay so is generally you know 36:25 there's a lot of misconceptions online 36:26 where people say well 36:28 uh the hole in the in the fibers of the 36:30 mask is is this big and 36:32 the virus is smaller it will go through 36:34 first most 36:35 again as i told you earlier the virus is 36:37 not there naked this is a much bigger 36:38 particle 36:39 and second it doesn't matter that the 36:40 hole is larger masks still work even if 36:43 the hole is larger 36:44 so then this would be one one important 36:46 thing and there is two links here that 36:47 explain there is a really good video 36:50 uh by minute physics on on n95 masks 36:53 that explains this 36:54 uh this very well on youtube yeah 36:58 um now filtering work works okay so we 37:02 a very good thing that we can do is just 37:04 open the windows or do something else 37:05 in which we take the air that's inside 37:08 and it goes outside 37:09 you know and we bring air that doesn't 37:11 have the virus and we will get inside 37:13 right 37:14 except maybe there is a lot of smoke and 37:16 then we choke ourselves right 37:17 so uh but there are places where because 37:20 it's smoky outdoors or because we don't 37:22 have windows or because you know we 37:23 cannot ventilate enough with outdoor air 37:25 we have to use filters right 37:27 and what's a filter again a mask is a 37:29 filter a mask is a filter we wear 37:32 but you can also use them in your hvac 37:35 system or you can have basically a box 37:38 in your living room that plugs in the 37:39 wall and it's a filter has a fan goes 37:41 into a filter 37:42 and uh they have a certain so these are 37:45 kind of 37:45 the type of filters we use in air 37:46 conditioning systems and they have 37:48 what's called the merv 37:49 rating and depending on the rating you 37:51 know they 37:52 they work better or worse again what's 37:54 important to remember is we're trying to 37:55 filter particles that are a micron or 37:57 larger 37:58 we're not trying to filter filter the 38:00 virus here we're not trying to filter 38:02 this 38:03 smoke which is here we're trying to 38:05 filter particles that are larger right 38:07 so even filters that are not very good 38:09 they're actually pretty good 38:11 um for this for this problem okay 38:14 and and there is the hepa filter that 38:16 you may hear a hepa filter is basically 38:19 you cannot distinguish it from the line 38:21 every particle of any size that has the 38:23 virus or 38:24 smoke it will go there and get stuck in 38:26 the filter 38:28 and this is true for masks as well mask 38:31 is just a filter you wear 38:33 so now for masks uh something that's 38:35 very important that has been lost in 38:37 this whole confusion with the drop 38:38 lights right 38:39 if you are trying to protect yourself 38:40 from a projectile so someone is going to 38:42 have a projectile that comes to me 38:44 what i need is a parapet a wall right 38:47 and then 38:48 that will intercept and it can be just 38:49 hanging in front of my face and it will 38:51 stop it right 38:52 if you are trying to defend yourself 38:53 from smoke a wall won't do it 38:55 the smoke will go on the wall right so 38:57 you need a mask to fit 38:59 snugly around your face right and we 39:01 need to spend effort you know basically 39:03 making sure we don't have any gaps have 39:05 someone look you know that this fits 39:06 well 39:06 on your nose and you have any um any 39:09 gaps in how your mask fits 39:11 and also another way to tell is when you 39:13 breathe in the mask gets close to your 39:15 face when you breathe out 39:16 the mask gets farther from your face 39:18 because there is a force by the air 39:20 that's going through the mask 39:21 if that doesn't happen that probably 39:23 means you have gaps somewhere and the 39:25 air is going through there 39:27 and there is a this very nice video here 39:29 that you can also find in youtube 39:31 uh which they do a demonstration 39:33 basically they have this mannequin which 39:34 is exhaling 39:35 um somatosouls and you see that when 39:38 they take these masks and they don't fit 39:39 them well then basically the aerosol 39:41 escapes everywhere 39:42 right and this is one of these k and 95 39:44 masks that you can even get but it's not 39:46 well fit you can 39:47 um attach it here on the nose well and 39:50 you see all this leakage 39:52 now if you see someone that's wearing a 39:53 mask that's not fitting well realize 39:55 that the curvature of the mask 39:57 is gonna sell send all the smoke all the 39:59 virus behind them 40:01 so the last place you want to be in this 40:02 pandemic is behind someone 40:04 that's wearing a mask that doesn't fit 40:06 well because if they are infected that's 40:08 where all the virus is going right you 40:09 should rather be in front 40:11 of course if if they're covering the 40:13 nose if you're not covering the nose 40:14 then 40:15 then run away um but in in these videos 40:19 well they show us this 40:20 this cloth mask that actually fits well 40:23 it's bigger than the other ones and when 40:24 you're watching the video you cannot see 40:26 any other results coming out 40:28 so for you know for people you know 40:31 healthcare or you know people who are 40:33 very high risk maybe this 40:34 95 masks make sense but for most of us 40:37 you know a good cloth mask is 40:39 is plenty good yeah now it's also really 40:42 important that we don't remove our masks 40:44 when talking 40:45 okay um you see routinely and even 40:48 though she does these you know 40:49 they were in their mask and they're 40:51 indoors and then they come to top and 40:52 they remove the mask 40:54 that's a very bad idea when we talk we 40:57 produce 40:58 you know five to thirty times more 40:59 aerosols than when we are used breathing 41:01 right 41:02 so you have a room and one person is 41:03 talking the person talking is the person 41:05 that should be 41:06 wearing the mask and especially more if 41:08 we're shouting or we're singing 41:09 something like that you know 41:11 if you're in a bar and it's very loud 41:13 and people have to shout 41:15 that's why we have outbreaks in bars you 41:17 know because 41:18 because of that type of behavior and no 41:20 masks and all that 41:23 okay so there is um and i forgot to put 41:25 the link but um 41:26 i'll put it on the slides that i will 41:28 send to amanda in 41:29 john vulcan so colorado state has a 41:31 database of 41:33 masks that they have been testing and um 41:36 and this is a picture 41:37 from it and this is again the size in 41:40 microns 41:41 and every color here is a different mask 41:43 okay 41:44 and what you can see is that they vary 41:45 all over the place you know you have 41:47 this one which is probably the worst 41:49 but basically it's taking out ten twenty 41:50 percent of them 41:52 i think this is a bandana or something 41:53 like that and then you have many ones 41:55 that are in between but then you have 41:57 some 41:57 that are used cloth masks but they are 41:59 well built and they actually filter 42:01 pretty much everything 42:02 as much as an n95 okay and there but 42:05 they are not n95 so 42:06 so it matters a lot which masks you wear 42:09 and you want to wear these ones right 42:10 and you can go to the website and and um 42:14 and see which ones those are uh this 42:16 came out recently so i haven't i want to 42:18 buy one of these myself but i haven't 42:19 had time to 42:21 get to go and see what they are okay um 42:24 let's see and remember the virus is here 42:26 right so you 42:27 so a mask like this is basically going 42:29 to remove all the virus if it's well fit 42:31 with well a mask like this is going to 42:33 not do a lot 42:36 now air cleaners also work so i said you 42:39 know 42:41 you have a filter in your in your 42:43 ventilation system something that may 42:44 look like this 42:45 you know you have force air heating and 42:47 cooling and you should replace these 42:49 we're recommending this merv 13 grade if 42:52 your system can handle it 42:53 but you know many times that maybe there 42:55 is no ventilation system or it cannot 42:57 handle it whatever so then you can use 42:58 air cleaners 43:00 and there is basically two types the 43:02 expensive one that works very well and 43:04 the cheap one right that still works 43:06 right especially in an emergency like 43:07 where 43:08 so this is an example of what we call a 43:10 hepa air purifier right 43:12 and this is a relatively big one and you 43:13 see it has a big price tag depending on 43:15 the 43:16 how big one you need it depends on the 43:17 size of the room right this particular 43:19 one was recommended by shelly miller 43:21 um what is this this is a box that has a 43:24 fan 43:24 air is sucked into the into the box all 43:27 the all dividers 43:29 stays in the filter and cleaner goes 43:30 outside this does the same thing but 43:33 by attaching a box fan to um one of 43:36 these spsc filters 43:38 and if you go to the frequently asked 43:39 questions there is a lot of details and 43:41 links 43:41 this costs fifty dollars or forty 43:43 dollars and it works very well it has 43:45 been 43:46 shown many times so this will be 43:48 something that basically almost anybody 43:50 can afford to make any situation safer 43:54 in terms of ventilation and this is 43:56 where things start to get a little bit 43:58 technical and i would i would you know 43:59 when people say how do i know my 44:01 ventilation is enough 44:03 um you need to measure the ventilation 44:06 and you need to 44:06 make sure you want to target these 44:08 numbers of you know 44:10 at least you know at least 10 but if 44:12 possible 25 liters of air per second per 44:15 person right 44:16 we sit on all these outbreaks they had 44:18 ventilation of the order of one to three 44:20 liters per second per person 44:22 right so you want to have much more 44:23 ventilation than that okay 44:26 uh this is from uh from shelly miller's 44:28 presentation 44:29 now talking less loudly also helps a lot 44:31 and this is from a paper from colleagues 44:33 and they said 44:33 depending on how many decibels you're 44:36 speaking 44:37 this is the chance of of transmission 44:40 under different ventilation conditions 44:42 so let's just look at this one with low 44:43 ventilation and you see 44:45 if you are speaking basically at the low 44:47 end of of 44:49 typical conversation maybe you have five 44:50 percent if you are talking as loud as 44:52 anyone with talking doors you have 40 44:54 so it makes a big difference and you 44:57 shouldn't let anyone talk to you without 44:59 a mask 44:59 much less talk to you loudly 45:02 um i'm almost out of time so but just to 45:05 mention if you go to this link 45:07 tenure url.com slash copy the estimator 45:10 we have a mathematical model where you 45:12 can calculate things for your situation 45:15 and it has a lot of explanation i will 45:16 not show it but i'm short of time 45:19 and the last thing is that we can use 45:22 co2 45:23 um i think in terms of doing one thing 45:26 the 45:26 the most practical thing for most people 45:28 will be to measure co2 45:29 okay and you want to avoid situations to 45:32 first order 45:32 where you have more than 800 per million 45:35 outdoors we have 400 45:37 humans breathe out co2 and breathe out 45:39 the virus 45:40 and well if you have a lot of co2 45:42 indoors it means there is a lot of 45:44 exhaled air from others and therefore 45:46 there may be viruses there we have 45:48 written um 45:49 a paper on this that is uh you know in 45:51 appropriate server 45:53 i could uh um send you a link if anyone 45:57 is interested 45:58 that deals with it in more detail i mean 45:59 the details matter but but to first 46:01 order you want to avoid 46:03 um things with high level of co2 and 46:06 this is an 46:06 example now this is done by the group at 46:08 harvard in which they started 46:10 with a thousand per million because they 46:12 have been breathing in a room 46:14 and now they just let you know the 46:16 window is closed in the room so you see 46:18 the co2 goes down goes down because the 46:19 air is slowly replaced you know so this 46:21 is 46:22 at zero and this is after half an hour 46:24 you know the amount of 46:25 exhaled air has gone down by a factor of 46:28 two but this is now when they open the 46:29 window on the door 46:30 right and suddenly you see the things go 46:32 down much faster right 46:33 and that in 15 minutes you basically 46:35 have ventilated bedrooms right 46:37 but remember ventilation needs to be 46:40 continuous 46:41 ventilation is not to open the door 15 46:43 minutes in the morning or 15 minutes 46:44 every hour 46:45 is to keep the window open at all times 46:47 when you are sharing the air with 46:48 someone else 46:50 okay so that's that's what i have time 46:52 to say so i 46:53 will go on to answer as many questions 46:56 as possible thank you 46:59 great thank you jose and everyone that 47:00 is on the presentation and thank you for 47:02 leaving some room for q 47:03 a we do have dozens of questions 47:05 streaming in so we won't be able to get 47:06 to everyone but 47:07 if you do have a question please submit 47:09 it through the q and a 47:10 interface um the first question we have 47:13 here is from matt 47:14 he said could you share more about 47:16 indoor conditions that might exacerbate 47:18 the spread of the virus for example 47:20 should we keep our room at a certain 47:22 temperature or try to keep the humidity 47:23 level at a certain level 47:26 um yeah so again in this um 47:30 if you go here we elaborate a lot about 47:32 temperature and humidity 47:33 um we don't think i mean there is some 47:38 discussion and it's probably true that 47:40 having it be a little more human so 40 47:42 to 60 humidity is better 47:45 but i don't think it's worth unless you 47:47 already have a humidifier then you 47:48 should run it 47:49 i don't think it's worth investing on it 47:51 i think you should invest in a filter 47:53 because the filter removes the virus 47:55 from the earth the humidity only makes 47:56 the virus die a little more slowly 47:59 and temperature makes very little 48:01 difference i mean we know the cold 48:03 help helps the virus but within the 48:05 range of indoor temperatures 48:06 you know making your room warmer is is 48:10 very unlikely to do a difference because 48:11 you will have to have the room at 100 48:13 degrees 48:14 to make a significant difference okay 48:17 thank you for that we're getting this 48:19 question a lot do you think flying on an 48:21 airplane 48:22 is safe could you tell us more about the 48:24 filters that they use and if you think 48:26 it would be safe to fly 48:28 oh let me see if i can find this 48:32 um i was gonna slide about that but um 48:36 uh for what's worth and then maybe on 48:39 the cashews cautious and the things 48:41 of of things i'm not gonna fly until i 48:44 have a vaccine 48:44 but you know that doesn't mean 48:48 may uh anyway that may be too cautious 48:52 but that's what i've decided 48:53 but basically the the airplane itself 48:55 when the engines are running 48:57 has very good ventilation right and it's 48:59 ventilation they go sideways 49:01 right and there is very good filters 49:03 they have these hepa filters and they 49:04 have a lot of air going going there so 49:06 basically if you get sick in the 49:07 airplane 49:08 it's going to be from the person that's 49:09 sitting next to you when they remove 49:11 their mask or something like that so if 49:13 you can keep your distance and you can 49:14 always wear your mask 49:16 you know then that's relatively safe 49:18 what gets less safe is 49:20 when you are boarding or deboling the 49:22 plane then the ventilation is not on or 49:24 this much is ventilation i mean 49:27 people see that when they measure the 49:28 co2 is much higher right so those are 49:30 riskier times 49:31 as is you know the um i forgot the 49:34 boarding this boarding structure where 49:36 you walk into the plane also doesn't 49:37 really have ventilation 49:39 as well as you know the depending on the 49:41 airport you know where you're waiting 49:42 and or the taxi or the bus or whatever 49:46 those can be higher risk situations and 49:47 the under risk accommodates right 49:49 also i should say when i say planes are 49:51 very safe i'm talking about you know 49:53 a 737 or 787 these regional planes 49:57 that you take you know the small plane 49:58 that you take to go to 50:00 you know some small town somewhere those 50:03 are much less well ventilated and will 50:04 be riskier i don't know 50:06 we're working with people to quantify 50:08 how much but they i will 50:09 stay away from those and you're gonna 50:12 fly 50:13 i would fly with the airlines that um 50:16 that don't put people on the middle seat 50:17 because again that's how you 50:19 could get uh could get infected so i 50:21 think it was delta and maybe american 50:24 um forget this i know it's delta for 50:26 sure and i would avoid the small planes 50:28 and i would go only with the big planes 50:30 okay great that absolutely makes sense 50:33 the next question here from linda 50:35 could you summarize the difference 50:36 between droplets and aerosols for 50:38 example what besides smoke 50:41 generates an aerosol um 50:44 so um smoke from the wildfires smoke 50:47 from a cigarette smoke from vaping 50:49 pollution you know the when you go to 50:52 the 50:53 the blue ridge mountains and you see the 50:55 the hay so when you see the haze here in 50:57 denver those are aerosols right 50:58 they are not falling from the ground 51:00 they're not falling to the ground 51:01 they're floating in the air basically 51:03 it's the same material it's just it's 51:05 just a ball 51:06 of saliva or something like that it's 51:08 just how big it is you know once it gets 51:09 big enough 51:10 you know like sand is gonna fuse fall to 51:12 the ground but when it's small enough 51:14 gravity is still trying to get it down 51:16 but but it's too small and then the 51:18 motion of the air is gonna keep it the 51:19 lost 51:20 right so that's basically that's 51:22 basically the difference and 51:26 okay thank you next we have a question 51:29 from mark he said is there any evidence 51:31 of transmission of covid19 51:33 via ducted air handling systems for 51:36 example from a known room with direct 51:38 exposure to occupants in a distant room 51:40 only explainable by ducted airflow 51:44 not that i know of and i think 51:48 my impression is that that this is 51:49 possible but not very likely 51:51 you know this virus is is often not so 51:54 contagious 51:56 uh not as contagious as the viruses that 51:58 do that i still think that's possible 52:00 but 52:00 but i don't think that's major i think 52:02 the 52:03 um is really when you are sharing a room 52:06 with others for a long time that we see 52:09 this super spreading right this is you 52:10 know is the choir you are 52:12 two hours in a room with no ventilation 52:15 singing 52:15 you know or a bar where people are 52:17 shouting whatever with the music 52:19 for a long time without masks or you 52:21 know the restaurant they were for an 52:22 hour in a place you know 52:24 it's more the kind of thing that we see 52:26 a lot of transmission 52:28 okay thank you we're also getting this 52:30 question a lot most recently from julie 52:32 in an enclosed room do ceiling fans make 52:35 the situation worse 52:38 um it depends i mean you know 52:41 if you are smoking in a room the smoke 52:44 is gonna mix in the room 52:46 sooner or later it may take 10 or 20 52:47 minutes right so now 52:49 if you turn on the fan you know if you 52:51 are next to the person smoking for you 52:53 is good because the smoke is diluted if 52:55 you are in the other side of the room 52:56 that's bad because the smoke is easier 52:58 earlier to you than good otherwise right 53:00 so it depends i mean 53:02 in general they don't i mean i don't 53:04 know it depends on the situation as i 53:06 said 53:07 what's useful is to have a fun in the 53:09 window 53:10 you know pushing her out or bringing her 53:12 in that's that's really the best use of 53:14 of a fan and again i should say you know 53:17 if you're at home with people who are in 53:18 your code or something 53:20 you don't have to be paranoid the virus 53:22 is not going to come from the air from a 53:23 mile away and 53:24 no no that's those are the miasmas that 53:27 that people hated and why we are in this 53:29 predicament you know it's when you're 53:30 sharing 53:31 the room with someone in fact you know 53:34 in the office or in a classroom or 53:36 whatever 53:37 okay thank you next we have a question 53:40 from bill he asks are merv 13 filters 53:42 critical 53:43 to prevent spread of aerosols in 53:45 recirculated air systems 53:47 with let's say 10 outside air i have not 53:50 heard that aerosols 53:51 actually build up through a building 53:53 hvac system um 53:56 [Music] 53:59 well they do you know so then 54:03 this is the theory that i showed so this 54:04 is the mark 13 right 54:07 and the murph 13 that's well installed 54:09 and something like that is filtering a 54:11 lot of the particles 54:12 and most systems you know have the 54:14 cheapest filter which tends to be a 54:16 murph eight 54:17 right so if you go from a mirth eight to 54:19 murf13 54:21 you're cutting the amount of virus 54:23 that's going to come back to you right 54:25 um so we think and we recommend that 54:28 that's a good idea 54:29 you know to increase the the filter you 54:31 can mer 13 is kind of a sweet spot that 54:34 it 54:34 is not too expensive it doesn't have too 54:37 much it 54:38 still lets the air go through but it's a 54:40 much better filter 54:41 right if you go to these ones they they 54:44 start choking 54:45 the fan too much and they become a 54:46 problem and also these are made of the 54:48 same material that we make in 95 so they 54:50 are not really available 54:52 right so mark 13 is what we recommend 54:54 now there are some 54:55 systems and they call us from schools 54:57 and they say if we put them our 13 54:59 the fund can't cope you know and then 55:01 they say we're going to go with 11 or 55:02 we're going to go 55:03 so put the best filter you can um 55:07 but uh you know 13 if you can 55:10 don't put the hepa filter on on those 55:12 systems unless it has been designed for 55:14 a hepa filter or it would really 55:16 choke it and damage the ventilation 55:18 system 55:19 okay great and taking a look at the time 55:21 we'll move into our final two questions 55:23 our next question is um coming from 55:26 quite a few people 55:27 could you share your thoughts on upper 55:29 air ultraviolet purification devices 55:33 so this is where shelley miller is the 55:35 expert but uh 55:36 um i will say i've learned enough from 55:39 her her to 55:40 to address this so filtering when people 55:43 say how do we clean their 55:44 filtering filtering filtering it's easy 55:47 it's cheap 55:48 get a portable filter get a fan filter 55:50 you know 55:51 um get masks all this kind of thing this 55:54 kind of thing 55:55 you know the uv systems are not any 55:57 cheaper right 55:58 they do work so it does kill the virus 56:00 that's that's known well 56:02 but they are more complicated they're 56:03 more expensive and those light bulbs 56:05 they 56:06 stop working in the uv but they still 56:09 make visible light so you have someone 56:10 that comes with a uv meter to see if 56:12 they're still working so they just 56:13 we recommend them in professional 56:15 situations you can have professionals 56:17 install them in a hospital or in another 56:19 situation where 56:20 release the only thing you can do then 56:22 go ahead and then there is 56:24 there is many other air cleaners that 56:25 work on oxidation and plasmas or even 56:28 this fogging of disinfectants 56:30 stay away from all that filters is what 56:33 you want 56:34 great thank you and our final question 56:36 again has been submitted by many 56:38 constituents here and that is could you 56:40 talk about how safe it is to stay in a 56:42 hotel 56:43 and is there a way that we can assess if 56:45 a hotel is using a well ventilated 56:47 system um you have to ask them 56:51 i mean again i see a two meter and sorry 56:53 i don't have my 56:54 my little co2 meter here but this they 56:56 are actually quite small and nice 56:58 would be a good way to see if there is 57:00 any recirculation i mean 57:03 if you have you're in a hotel basically 57:05 you can open your windows and there is 57:07 no air coming from other places that 57:08 would be a good situation if 57:10 if there was a hotel in which for some 57:12 reason you were getting air from other 57:14 rooms that would be 57:16 that would be riskier and there are 57:18 cases in 57:20 for sars for example there were cases in 57:21 hotels 57:23 but for example one of these motels 57:25 where you basically have your door on 57:27 your windows 57:28 that would be the safest alternative i 57:29 would say okay 57:31 great well thank you and thank you so 57:34 much to everyone for joining us for 57:35 today's presentation 57:36 and thank you again to jose for this 57:38 great information at this time we invite 57:40 you to provide your feedback on the 57:42 webinar by answering the following poll 57:44 question 57:45 on a scale from 1 to 10 how likely are 57:47 you to recommend 57:49 this webinar to a friend or other cu 57:51 boulder alumni 57:52 please take a moment to 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