Skip to content
  • Home Home Home, current page.
  • Moments Moments Moments, current page.

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @
  • Language: English
    • Bahasa Indonesia
    • Bahasa Melayu
    • Català
    • Čeština
    • Dansk
    • Deutsch
    • English UK
    • Español
    • Filipino
    • Français
    • Hrvatski
    • Italiano
    • Magyar
    • Nederlands
    • Norsk
    • Polski
    • Português
    • Română
    • Slovenčina
    • Suomi
    • Svenska
    • Tiếng Việt
    • Türkçe
    • Ελληνικά
    • Български език
    • Русский
    • Српски
    • Українська мова
    • עִבְרִית
    • العربية
    • فارسی
    • मराठी
    • हिन्दी
    • বাংলা
    • ગુજરાતી
    • தமிழ்
    • ಕನ್ನಡ
    • ภาษาไทย
    • 한국어
    • 日本語
    • 简体中文
    • 繁體中文
  • Have an account? Log in
    Have an account?
    · Forgot password?

    New to Twitter?
    Sign up
jljcolorado's profile
Prof. Jose-Luis Jimenez
Prof. Jose-Luis Jimenez
Prof. Jose-Luis Jimenez
Verified account
@jljcolorado

Tweets

Prof. Jose-Luis JimenezVerified account

@jljcolorado

Dist. Prof. Chem. & CIRES, Univ. Colorado. #HighlyCited2021, Fellow AAAR & AGU. Aerosols, pollution #EndFossilFuels #COVIDisAirborne http://Bit.ly/FAQ-A  http://Bit.ly/c-est 

Boulder, CO
colorado.edu/chemistry/jose…
Joined July 2009

Tweets

  • © 2022 Twitter
  • About
  • Help Center
  • Terms
  • Privacy policy
  • Cookies
  • Ads info
Dismiss
Previous
Next

Go to a person's profile

Saved searches

  • Remove
  • In this conversation
    Verified accountProtected Tweets @
Suggested users
  • Verified accountProtected Tweets @
  • Verified accountProtected Tweets @

Promote this Tweet

Block

  • Tweet with a location

    You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more

    Your lists

    Create a new list


    Under 100 characters, optional

    Privacy

    Copy link to Tweet

    Embed this Tweet

    Embed this Video

    Add this Tweet to your website by copying the code below. Learn more

    Add this video to your website by copying the code below. Learn more

    Hmm, there was a problem reaching the server.

    By embedding Twitter content in your website or app, you are agreeing to the Twitter Developer Agreement and Developer Policy.

    Preview

    Why you're seeing this ad

    Log in to Twitter

    · Forgot password?
    Don't have an account? Sign up »

    Sign up for Twitter

    Not on Twitter? Sign up, tune into the things you care about, and get updates as they happen.

    Sign up
    Have an account? Log in »

    Two-way (sending and receiving) short codes:

    Country Code For customers of
    United States 40404 (any)
    Canada 21212 (any)
    United Kingdom 86444 Vodafone, Orange, 3, O2
    Brazil 40404 Nextel, TIM
    Haiti 40404 Digicel, Voila
    Ireland 51210 Vodafone, O2
    India 53000 Bharti Airtel, Videocon, Reliance
    Indonesia 89887 AXIS, 3, Telkomsel, Indosat, XL Axiata
    Italy 4880804 Wind
    3424486444 Vodafone
    » See SMS short codes for other countries

    Confirmation

     

    Welcome home!

    This timeline is where you’ll spend most of your time, getting instant updates about what matters to you.

    Tweets not working for you?

    Hover over the profile pic and click the Following button to unfollow any account.

    Say a lot with a little

    When you see a Tweet you love, tap the heart — it lets the person who wrote it know you shared the love.

    Spread the word

    The fastest way to share someone else’s Tweet with your followers is with a Retweet. Tap the icon to send it instantly.

    Join the conversation

    Add your thoughts about any Tweet with a Reply. Find a topic you’re passionate about, and jump right in.

    Learn the latest

    Get instant insight into what people are talking about now.

    Get more of what you love

    Follow more accounts to get instant updates about topics you care about.

    Find what's happening

    See the latest conversations about any topic instantly.

    Never miss a Moment

    Catch up instantly on the best stories happening as they unfold.

    1. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      14/ WHO’s video is starkly clear about this, as are other sources: https://twitter.com/WHO/status/1244258441880797184 … This is why WHO says that no masks are needed indoors if a distance of 1 m can be kept (https://www.who.int/news-room/q-a-detail/q-a-how-is-covid-19-transmitted# …). And, I think, this is why many are so confused about masks.pic.twitter.com/S4CurtJb6D

      3 replies 18 retweets 117 likes
      Show this thread
    2. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      15/ Smaller, invisible aerosols float in the air and behave in less obvious ways. The best analogy is cigarette smoke, which is an aerosol. Think about (or experiment with) how smoke moves, and dilutes, and you can get the gist of what is going on.pic.twitter.com/LrKYjbcFvw

      8 replies 50 retweets 178 likes
      Show this thread
    3. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      16/ Again, understanding how the infectious payload is delivered through the air from the infected to the susceptible person is a critical problem, and if we don’t invest enough effort on it and engage the experts, we can get it seriously wrong.

      1 reply 19 retweets 132 likes
      Show this thread
    4. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      17/ Aerosol scientists would seem needed, but perhaps @WHO already understands this well and doesn’t need the help? Let’s investigate if that’s the case.

      1 reply 10 retweets 82 likes
      Show this thread
    5. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      18/ As of this writing WHO’s latest scientific briefing (https://who.int/publications/i/item/modes-of-transmission-of-virus-causing-covid-19-implications-for-ipc-precaution-recommendations …) states that aerosol-droplet boundary is 5 um. Same in a recent paper from the members of the key WHO committee (https://aricjournal.biomedcentral.com/articles/10.1186/s13756-020-00779-6 …) Same in Klompas et al. in JAMA (https://jamanetwork.com/journals/jama/fullarticle/2768396 …)pic.twitter.com/n9CEiLelg1

      2 replies 12 retweets 73 likes
      Show this thread
    6. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      19/ But the real boundary between ballistic droplet behavior (falls within 1-2 m, infects by impact) and aerosol behavior (travels > 2 m, infects by inhalation at any distance) is at around ~100 um. Stay tuned about what caused the 5 um error, coming soon to a preprint near you

      2 replies 18 retweets 120 likes
      Show this thread
    7. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      20/ The real aerosol-droplet boundary is discussed in multiple published papers, going back to Wells (1934): https://academic.oup.com/aje/article/20/3/611/280025 … See also:https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.2007.00469.x …

      1 reply 18 retweets 98 likes
      Show this thread
    8. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      21/ But it is even worse, to be able to reach others at distances of 0.5-1m when talking, ballistic droplets need to be >300 um. Work by Yuguo Li (invited presenter at WHO 900-person webinar 2 weeks ago) https://www.sciencedirect.com/science/article/abs/pii/S0360132320302183 …), similar independent work https://aip.scitation.org/doi/10.1063/5.0021427 …

      1 reply 17 retweets 76 likes
      Show this thread
    9. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      Prof. Jose-Luis Jimenez Retweeted Prof. Jose-Luis Jimenez

      22/ It took 50 tweets to explore the 100 um vertical motion and 300 um horizontal motion thresholds in detail, so I’ll refer you to the previous "angry birds" thread:https://twitter.com/jljcolorado/status/1292880342227984385 …

      Prof. Jose-Luis Jimenez added,

      Prof. Jose-Luis JimenezVerified account @jljcolorado
      1/ Aerosols, droplets, & “flexible droplets” Trying to clarify key aspects. Details complex, give bottom lines 1st: Bottom line 1: If fall within 1-2 m of the person (WHO or CDC droplets), then **have to** infect by ballistic impact (“angry birds”). Cannot infect by inhalation pic.twitter.com/rixqF4iSrI
      Show this thread
      1 reply 16 retweets 91 likes
      Show this thread
    10. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      23/ Aerosol and droplet motion is a dramatic function of size, since mass increases with the cube of the diameter. So I decided to make it visual. It is hard to overstate how large of an error @WHO and others are making.

      3 replies 14 retweets 83 likes
      Show this thread
      Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

      24/ If the virus is the size of a squirrel, WHO is saying that droplets start at the size of an elephant. But really, droplet behavior starts at the size of Godzilla! (https://www.popularmechanics.com/culture/movies/a10476/the-impossible-anatomy-of-godzilla-16785535/ …)pic.twitter.com/C0TJzW1x5O

      5:55 PM - 17 Aug 2020
      • 77 Retweets
      • 234 Likes
      • Dr Marianne Adrian Engler Benjo Buensuceso danfnz Shane Bond jluis.oje Sam Mida CO2, Ventile, Filtre aire con N95,P100,MERV13 efna
      5 replies 77 retweets 234 likes
        1. New conversation
        2. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          25/ The relative error in size is as large as if aerosol scientists confused virus w/ bacterium, or (larger) bacterium w/ amoeba And responses we often get are the equivalent of us making those errors & saying “microbe, schmicrobe”. For many ppl does seem “microns, schmicrons”

          1 reply 15 retweets 96 likes
          Show this thread
        3. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          26/ Limited understanding of aerosols appears again and again in a series of “myths”: (a) If it’s aerosol, it has to be like measles (b) If it’s aerosol, it has to infect at long range (c) If infects at close proximity, it proves droplets and disproves aerosols

          1 reply 23 retweets 135 likes
          Show this thread
        4. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          27 (myths continued) (d) If it’s aerosol, then surgical masks are useless (e) If it’s aerosol, R0 must be very high

          1 reply 18 retweets 113 likes
          Show this thread
        5. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          28/ Those myths are all false, as I’ve discussed before (https://www.medscape.com/viewarticle/934837?src=uc_mscpedt&faf=1#vp_1 …). These myths are often implicitly or explicitly applied to interpret the results of studies in very complex situations, leading to incorrect conclusions.

          3 replies 27 retweets 117 likes
          Show this thread
        6. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          29/ Indeed “This issue is more nuanced than many of them realize” (quote from a @WHO committee member) is perhaps also true in the opposite direction.pic.twitter.com/vamBO9zgSt

          3 replies 14 retweets 76 likes
          Show this thread
        7. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          Prof. Jose-Luis Jimenez Retweeted Prof. Jose-Luis Jimenez

          30/ Hospital CEO: "When our children get sick, we call a pediatrician. If our roof leaks, we call a roofer. And if we're having problems with our teeth, we do not call the auto mechanic, we call a dentist who has been trained to take care of that problem”https://twitter.com/jljcolorado/status/1295016533849018369 …

          Prof. Jose-Luis Jimenez added,

          Prof. Jose-Luis JimenezVerified account @jljcolorado
          Thoughtful hospital CEO @JamesEKHildreth about aerosol transmission and what it means for schools. Very much worth reading. https://www.newschannel5.com/news/meharry-ceo-dr-james-hildreth-says-new-research-shows-its-not-safe-to-open-schools …
          Show this thread
          4 replies 17 retweets 91 likes
          Show this thread
        8. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          31/ So when aerosols could be involved in transmission, and the results of evaluating whether they do or don't have huge implications... shouldn’t aerosol scientists be deeply involved in the studies and committees that will make that determination?

          4 replies 23 retweets 144 likes
          Show this thread
        9. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          32/ Our message about 5 um error has been heard. So the new way to deal with it seems to be to say something like: “It is recognized that there is a continuum of transmission routes between large droplet and aerosol and it is an important concept.”https://aricjournal.biomedcentral.com/articles/10.1186/s13756-020-00779-6 …

          2 replies 17 retweets 78 likes
          Show this thread
        10. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          33/ This seems to allow stretching droplets into what I call “magical droplets”, entities that allow explaining outbreaks, but are still firmly droplets (and thus don’t require recognizing aerosol transmission). But they don’t seem to have clearly defined properties such as size

          1 reply 12 retweets 65 likes
          Show this thread
        11. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          34/ Liberated from the tyranny of size, their amazing behavior allows explaining any superspreading event without having to give up that COVID-19 is a droplet/fomite disease. May I offer a visual for the “magical droplets” ;-) https://www.theonion.com/researchers-warn-coronavirus-may-use-propeller-hat-to-s-1844282753 …pic.twitter.com/hQnWdbihTR

          2 replies 30 retweets 135 likes
          Show this thread
        12. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          35/ Why people resorting to magical droplets? Thomas Kuhn in “Structure of Scientific Revolutions” (https://www.uky.edu/~eushe2/Pajares/Kuhn.html …): "Scientists faced w/ failing theory “devise numerous articulations & ad hoc modifications of their theory in order to eliminate any apparent conflict”

          5 replies 31 retweets 130 likes
          Show this thread
        13. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          36/ In this case the ad hoc modifications take the shape of partially acknowledging some clear aerosol transmission, but still cast it as an extension of droplet behavior. And thus removing the need to more clearly admit aerosol transmission.

          2 replies 16 retweets 81 likes
          Show this thread
        14. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          Prof. Jose-Luis Jimenez Retweeted Prof. Jose-Luis Jimenez

          37/ Droplet transmission is failing to explain the observations at a massive scale (https://docs.google.com/presentation/d/11rY9tQtkFaV_M4N-hf5qp1_Xtuw8JYb4Qvv5e7BEmcc/edit#slide=id.p …), from the reduction of transmission outdoors, to superspreading events E.g. in 41 outbreaks in bars in Louisiana , w/ 11 cases per outbreak:https://twitter.com/jljcolorado/status/1294490285712396289 …

          Prof. Jose-Luis Jimenez added,

          Prof. Jose-Luis JimenezVerified account @jljcolorado
          Contact tracing data from Louisiana, by type of location "Winners": industrial settings, bars, restaurants, retail, food processing, and daycare Also substantial (>5): offices, other worksites, religious services, automotive, wedding, casino, gym https://www.npr.org/sections/health-shots/2020/08/14/902271822/13-states-make-contact-tracing-data-public-heres-what-they-re-learning … pic.twitter.com/xHIPtrBT83
          Show this thread
          1 reply 21 retweets 91 likes
          Show this thread
        15. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          38/ So I’ll end with a plea. We are in this pandemic together. The different disciplines need to work together to understand the modes of transmission and interpret evidence. I had to offer some criticisms and point out some major errors in this thread.

          2 replies 28 retweets 136 likes
          Show this thread
        16. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          39/ Never before COVID-19 had ever done anything like this. I hope I can stop criticizing very soon, because the relevant bodies will have taken a new attitude and created more scientifically diverse teams to attack these complex problems.

          11 replies 14 retweets 128 likes
          Show this thread
        17. Prof. Jose-Luis Jimenez‏Verified account @jljcolorado 17 Aug 2020

          Prof. Jose-Luis Jimenez Retweeted Thread Reader App

          https://twitter.com/threadreaderapp/status/1295530227322376192?s=19 …

          Prof. Jose-Luis Jimenez added,

          Thread Reader App @threadreaderapp
          Replying to @EleNaturVal
          Hello, the unroll you asked for: @jljcolorado: 1/ On the need for a **true multidisciplinary approach** to aerosol & droplet transmission (aka “the… https://threadreaderapp.com/thread/1295518786951319552.html … Talk to you soon. 🤖
          3 replies 12 retweets 38 likes
          Show this thread
        18. End of conversation

      Loading seems to be taking a while.

      Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.

        Promoted Tweet

        false

        • © 2022 Twitter
        • About
        • Help Center
        • Terms
        • Privacy policy
        • Cookies
        • Ads info