Mastodawn

Morgan Aug 14, 2023

A lot of people still think about Covid as a wash your hands and socially distance kind of thing.

Chances of getting Covid from touching something is near zero and we're far more likely to catch it from someone we can't see because it can stay in the air for a long time, drift long distances, and remain potent long after a contagious person is gone (as much as 2 hours).

This is why improving ventilation is one of the most important things you can do to reduce risks of infection for yourself and people around you. With good air flow, an infectious person is less dangerous. Infected air is diluted and can't linger to keep infecting.

I took a variety of CO2 readings to estimate indoor air quality. Based on these readings, places I wouldn't want to be unmasked would be: house gatherings, offices, meeting rooms, conventions, public transit, a plane, funerals.

Places that may not be as risky as originally believed are: supermarkets, pharmacies, and restaurants.

#Covid #CO2 #Aranet4

Sheldon Aug 7, 2023

One surprising finding I'm having from taking CO2 readings in various places is that I'm consistently getting readings between 700 and 800 ppm at supermarkets.

I mostly took readings at peak hours. I'll need to go back at off peak times to see how much the readings change. I was really amazed at how "not terrible" the reading at Trader Joe's was.

Picture 1: Trader Joes at noon on a Saturday. It is packed. It was a total surprise to see CO2 readings between 700 and 800ppm! (Fair)

Picture 2: Smart and Final, a mostly California-bases grocery outlet selling a mix of regular groceries and bulk package items with a reading of 714ppm. (Good)

Picture 3: Walgreens Pharmacy, at off peak hours. 529ppm. This is very good, but hard to believe. I'll have to go take this again.

Picture 4: Nob Hill Foods, a small grocery chain in Northern California. 726ppm. Good-Fair.

#aranet4 #co2 #covid #traderjoe

Sheldon Aug 7, 2023

I'm making some blunt assumptions about what these readings mean. From what I've been gathering from scientists posting about air quality readings, 400ppm is a baseline and every +200ppm gets you from excellent to good to fair to unhealthy.

Most people seem to be suggesting 800 and below as the line to really start exercising more strict caution if you're trying to avoid infection.

But keep in mind that's based on 400ppm as the baseline. My baseline for some of these readings is shown in the attached photo. It's 470ppm outdoors on that day.

My baseline is likely higher because I'm in an urban area at a mall near very busy roads. There's a lot of extra ambient CO2 so my cutoff lines would be 670 and below (excellent), 870 and below (good), 1070 and below (fair).

Every 400ppm above baseline roughly equates to 1% of the air you breathe being exhaled by someone else. That's like getting mouth to mouth once every 6-8 mins.

#aranet4 #co2 #covid

Sheldon Aug 7, 2023

Want to see what a CO2 chart for an office meeting with about 12 people for one hour looks like? We start with excellent indoor air quality at 9am with 500ppm of CO2.

After one hour in a poorly ventilated space, the CO2 readings are 1720ppm! And this is a fairly spacious office that would have a bit of air reservoir to slow down the rise in CO2 levels.

Yikes! This means everyone is breathing quite a bit out of each other's lungs. If you're only going to wear a mask in the riskiest situations, this should be one of them.

Keep in mind that just having high CO2 concentrations doesn't mean much unless someone is contagious in the room, but if there was someone contagious that day, lots of people in that meeting would have gotten whatever was being passed into the air be it Covid, flu, RSV, or a cold.

#aranet4 #co2 #covid

Sheldon Aug 7, 2023

I'm sharing all of this with you because we could still be in for another wave and lots of people have waned immunity and prior infection isn't good at keeping you from getting a next infection.

It's also because I'm realizing among my real world friends that some are still focusing on hand washing to avoid getting Covid.

They're also trading lower risk activities for higher risk ones because they don't understand how it works. My friends who do catering told me they were catering huge house parties every day during the height of the pandemic when restaurants were closed for dine-in.

Restaurants have modern HVAC systems and have to pass building inspections. I've been surprised that readings in most restaurants are quite good (off peak at least). Very few homes will have ventilation systems like those in even a run down restaurant.

Going to a house party instead of meeting at a restaurant is a bad trade-off!

Sheldon Aug 12, 2023

I spent some time inside a variety of food/retail businesses this week as a photographer. Here's an #Aranet4 #CO2 reading from a bakery where the owner is very Covid conscious. She keeps it very well ventilated. This small bakery cafe was at full capacity with 15+ people. The CO2 reading was 471ppm against an outside reading of 415ppm.

Front door open w/commercial kitchen in the back pumping air. That it was windy also helped.

Also took a reading deep in a packed small Thai restaurant w/Covid aware owner. 550ppm, door open + all windows 1/4 open. Very surprised it was that low.

I've yet to measure a restaurant exceeding 800ppm (which is roughly 1% of re-breathed air per breath).

I may eventually feel just fine dining indoors in some places once we have some more clarity with the direction that #Covid & therapies are heading. On the flip side, there are types of places that often have bad airflow that I'm never looking at the same again.

My last 2 eye clinics both hit 1000ppm. 🤔

#CovidisAirborne

Deb has moved! (see profile) 🇨🇦Aug 13, 2023

@sysop408 when my knee is bad I take the elevator between subway platform and street. Or I would, if people would mask there.

One time I passed on the elevator 2x to avoid that confined space with unmasked people (who've been unmasked all day and all week, who knows what they're exhaling?*). The third time I gave up and walked the stairs despite my knee.

* studies show: up to 20% of #covid19 cases are asymptomatic 😱

Please mask in enclosed spaces, folks. 😷
If not for you, then for me.

Andrew Hoyer Aug 13, 2023

@sysop408 On a day-to-day basis, I do not think about COVID. I'm in gatherings of 100 - 200 people every week, fairly busy restaurants, and crowded shopping areas (Costco), and never think twice about it.

As a cold/flu type of virus, it's not going to be stopped by social distancing, masks, etc. It still hit everyone despite the attempt, so is it worth doing it now?

Sheldon Aug 14, 2023

@andrewhoyer if you see the first post, you'll see something that may support what you said.

Places like Costco and busy popular restaurants have modern HVAC systems and even if they're not trying to follow good ventilation practices, they probably still are because if you pack people in a restaurant, it'll get hot and smelly. Also, people don't tend to stay in a restaurant, Costco, or supermarket for 3 hours.

Social distancing isn't very effective b/c even in a peak infection period, the chance anyone near you is highly infectious is much less than 1 in 100.

The chance of you being at the same place with one of those people? Quite high, but if the ventilation is good, the chance of there being enough virus in the air to infect someone with a normal immune system is very small.

If you just avoid enclosed spaces w/poor ventilation & especially ones w/lots of people your chance of getting any respiratory virus goes way down. So far I'm finding most food/large retail buildings much safer than expected.

Sheldon Aug 14, 2023

@andrewhoyer I know you just want to get on with life, but here's one reason why you shouldn't just treat it as a cold/flu.

Flus are pretty dangerous in their own right. The reason why they're not as much of a public health concern is because it's much harder to catch the flu and there's rarely more than 3 month winter window where healthy people are likely to get it.

It's summer. There are people on their 3rd bout this year. Nobody gets the flu 3x.

All viral illnesses come with a chance of long term disability each time you get infected. Covid's long term risk is higher (so far). My wife is disabled because of another virus. I live everyday with the consequences of an unlucky infection.

Really, it's in your best interest to favor clearer air and maybe avoid 5-10 flus or Covids in your lifetime. Could be as simple as sitting near the door at a cafe or asking to crack open a window a bit. You don't have to go thru the whole ordeal of excluding risk to do small things to bend the numbers in your favor.

Derek Aug 7, 2023

@sysop408 it's bad for other indoor air hazards like VOCs or mould. If there is a ventilation system, it's likely broken so you may be at risk for legionnaires disease.

nshrubs Aug 7, 2023

@sysop408 @ingalls This looks like my classroom - 26 kids, 70-year-old school, windows sealed shut, no A/C. They tested the CO2 over several days, came back & retested the next week because they thought there was an error. No error. Explains why we're all sluggish & sleepy by midafternoon, especially on hot days, & reinforces why I stay masked inside at school.

Sheldon Aug 7, 2023

@Nshrubs @ingalls I've only been toying with this so it'd be awfully precious of me to think I know anything from this, but it sure does appear like classrooms are one of our biggest risks that we're barely doing anything about.

It seems like a lot of people who took at least some precautions managed to remain Novids untl their kids brought it home.

@sysop408
Yeah there's only so much you can do as parents, you can't lock your kids up at home as that's awful for their development, but you also have to pretty much accept what their school or daycare is doing.

I guess because COVID is supposedly (largely, I know tragically not for many) less bad for kids, they've been stuck with the short end of the stick.

@Nshrubs @ingalls

Sheldon Aug 7, 2023

@sarajw yeah, kids are getting the short end of the stick for sure. We really won't know what the long term effects of Covid are on kids.

@Nshrubs @ingalls

@sysop408 No. It definitely worries me.

@Nshrubs @ingalls

Sheldon Aug 7, 2023

@sarajw one reason for optimism is that if there are long term impacts, so many people will be affected that there’ll be lots of medical research and likely therapies.

@Nshrubs @ingalls

Yeah. ooof I mean yes - but also I don't like the idea of an Alzheimer's boom

Ursidinoj/The Bjornsdottirs Aug 7, 2023

@sysop408 @sarajw @Nshrubs @ingalls we will know. we shouldn't want to know. we should be doing everything we can to ensure that they're not exposed...

@ellenor2000
Yep I just went looking up details of getting my kids booster shots only to find the German STIKO has rolled back any advice to give kids Corona vaccines AT ALL.

@sysop408 @Nshrubs @ingalls

Ursidinoj/The Bjornsdottirs Aug 7, 2023

@sarajw @sysop408 @Nshrubs @ingalls Holy. And in germany homeschooling is banned.

I fear for germany in 2035.

@ellenor2000
Karl Lauterbach was a great voice on Corona dangers but since he got into government office I feel like he's just gone "meh" on it all.

@sysop408 @Nshrubs @ingalls

nshrubs Aug 7, 2023

@sysop408 @sarajw @ingalls I've had several students develop long term effects after just one infection. One of my former 2nd graders got it pre-vaccine. Now has asthma, inhaler in the nurse's office. Another former student basically has chronic fatigue/long COVID & only comes to school 3-4 days a week now. Another one has had GI issues ever since she had COVID. Just the tip of the iceberg.

TransitBiker Aug 7, 2023

@sysop408 @Nshrubs @ingalls That is my one big fear - that once the kids go back, we will get sick all the time. Except for one strange instance, we have not been sick at all in three entire years.

@pineywoozle ‘s #3WordNote Sep 2, 2023

@sysop408 @Nshrubs @ingalls They we’re given billions in grant money for school air quality improvement. It remains largely unspent. Some GOP controlled schools have even rejected gift of Corsi boxes. We all need to be pressuring them at local levels. Please don’t say discard the notion of masks, that’s insane. ALL the measures should be observed. No one is hurt by wearing a mask while we work on improving air but lots can be if those who are wearing them stop

Sheldon Sep 2, 2023

@Pineywoozle ah, so notice this thread is simply focused on ventilation. I'm intentionally mostly avoiding the masking conversation. If you understand how masks do and don't work, we're on the same page and the conversation I'm trying to have is with the person next to you.

@Nshrubs @ingalls

@pineywoozle ‘s #3WordNote Sep 2, 2023

@sysop408 @Nshrubs @ingalls This was the part that I was addressing - “A lot of people still think about Covid as a wash your hands and socially distance kind of thing. Please throw that out”

Nothing should be thrown out. If you suggest it for one thing like social distancing it translates to “Oh I don’t need to take in person precautions” Current vaccines work better against the new variant the lower you keep your viral load. It all matters.

Sheldon Sep 2, 2023

@Pineywoozle keep washing your hands, but don't do it because you think it's helping you avoid Covid. Tons of people still think that's a key infection pathway. To this day, we have yet to conclusively identify cases that were from fomites. I'm sure they're out there, but it's rare.

Because of the work I do with small businesses, I deal with the world at a retail level. Tell someone to do three things and they may get overwhelmed and do none of them. My message isn't about being perfect. It's about what has a chance of getting through to the many people who tuned out sometime in December 2020.

There are plenty good reasons to wash your hands, but it may actually be harmful messaging if it causes some people to focus on it at the detriment of avoiding enclosed spaces with stale air. I started this thread after being with friends who were all unmasked in a room talking about how they kept washing their hands because they didn't want to get Covid again.

@Nshrubs @ingalls

@pineywoozle ‘s #3WordNote Sep 2, 2023

@sysop408 @Nshrubs @ingalls I understand how low the fomite route is. I also dealt w/ boutiques for a decade & I agree people are overwhelmed by too much info but they also infer things that are close to what’s said but way off the mark & that’s the part I was addressing. You saying “Throw that out” is going to hit a lot of brains as the message “social distancing doesn’t matter so masks must not either.” Untill air quality improves all of what we say matters

Sheldon Sep 2, 2023

@Pineywoozle here's the reason why I de-prioritize social distancing when I'm trying to get people to focus on the one single most effective societal level intervention.

Social distancing protects you from close contact transmission which is a lot less common than the typical story of "I have no idea how I got it. Nobody around me seemed sick and I didn't get too close to anyone!"

In my area at peak pandemic when there was plenty of testing and monitoring, the chances of coming face to face with an infectious person was likely much much less than 1 in 100 on the average. Chances of you entering the same space as an infectious person? Quite high.

Infections tend to cluster in populations so once it enters your social group, your chances of direct contact do go way up, but your risks from indirect contact are always going to be orders of magnitude higher.

I don't find social distancing messaging to be helpful in 2023. It's correct, but I don't find it effective at the population level.

@Nshrubs @ingalls

@pineywoozle ‘s #3WordNote Sep 2, 2023

@sysop408 @Nshrubs @ingalls I get all that. Literally all I was addressing was that if you say “throw that out” You think your just deprioritizing and people will take it as permission to throw out way more than you intend. The general public is always playing a game of telephone and the message is always garbled. Emphasize the stuff about air quality for sure but for my money you should guard against what you see as harmless deprioritizing.

Sheldon Sep 2, 2023

@Pineywoozle ok. I accept that criticism and I've updated my post to take out the "Throw that out" because it might be misleading.

@Nshrubs @ingalls

@pineywoozle ‘s #3WordNote Sep 2, 2023

@sysop408 @Nshrubs @ingalls I really liked your posts and honestly it wasn’t ment as a bad criticism just me sharing how easily it could be misconstrued. We’re all in this together🥰

nshrubs Sep 2, 2023

@Pineywoozle @sysop408 @ingalls My district never got any grant $ for ventilation. (I just bought a second air purifier for my classroom.) My 1955 school building won't even be getting a proper remodel because the WA State legislature let our school districts go off a budget cliff (of their creation) & are refusing to fully fund public ed, so my district has scaled back all remodel plans to only the bare essentials, like replacing our 43-year-old rotting carpet & painting our classrooms.

TransitBiker Aug 7, 2023

@Nshrubs @sysop408 @ingalls I call that the “movie theatre effect”. Ever noticed how toward the end of a movie you’re starting to get sleepy? Well, that’s not because the movie is long or because you’re tired. It’s because of the gigantic buildup of carbon dioxide in the screening room. As soon as you head outside in the open air, you start to wake up. Scary.

Hans Gerwitz Aug 7, 2023

@sysop408 IIRC at those levels you’re already reducing cognitive performance, as a well

Sheldon Aug 7, 2023

@hans there’s that too so even more reason to get some air.

Robin Stephenson Aug 7, 2023

@sysop408 there's also a potentially significant cognitive impairment with that kind of CO₂ level—best to not take any important decisions in that meeting…

ref https://www.nature.com/articles/s41370-018-0055-8

Airplane pilot flight performance on 21 maneuvers in a flight simulator under varying carbon dioxide concentrations - Journal of Exposure Science & Environmental Epidemiology

Recent studies suggest that carbon dioxide has an impact on cognitive function performance of office workers at concentrations previously thought to be benign (1000–2500 ppm). The only available data for CO2 on the flight deck indicate that the average CO2 concentrations are typically <1000 ppm, but the 95th percentile concentration can be as high as 1400 ppm, depending on airplane type. We recruited 30 active commercial airline pilots to fly three 3-h flight segments in an FAA-approved flight simulator with each segment at a different CO2 concentration on the flight deck (700, 1500, 2500 ppm). CO2 concentrations were modified by introducing ultra-pure CO2 into the simulator; ventilation rates remained the same for each segment. The pilots performed a range of predefined maneuvers of varying difficulty without the aid of autopilot, and were assessed by a FAA Designated Pilot Examiner according to FAA Practical Test Standards. Pilots and the Examiner were blinded to test conditions and the order of exposures was randomized. Compared to segments at a CO2 concentration of 2500 ppm, the odds of passing a maneuver as rated by the Examiner in the simulator were 1.52 (95% CI: 1.02–2.25) times higher when pilots were exposed to 1500 ppm and 1.69 (95% CI: 1.11–2.55) times higher when exposed to 700 ppm, controlling for maneuver difficulty, Examiner and order of maneuvers. Examiner rating captured a wider range of performance indicators than output from the flight simulator, which can characterize only a few quantitative aspects of the flight performance. More broadly, these findings suggest that there is a direct effect of carbon dioxide on performance, independent of ventilation, with implications for many other indoor environments that routinely experience CO2 concentrations above 1000 ppm.

Nature

Rodney Aug 7, 2023

@sysop408 Even without covid or other airborne communicable diseases, it means less oxygen per brain in the room, which makes people tired and irritable, increasing workplace tensions.

It's just bad business to have meetings.

Josh Kramer Aug 8, 2023

@sysop408 another reason companies should want to improve circulation, even if they don't care about protecting against communicable diseases https://www.theatlantic.com/science/archive/2019/12/carbon-dioxide-pollution-making-people-dumber-heres-what-we-know/603826/

The Human Brain Evolved When Carbon Dioxide Was Lower

There is substantial but inconsistent evidence that as carbon-dioxide levels rise, they could affect human cognition.

The Atlantic

Bruce Mirken Aug 7, 2023

@sysop408 Obviously CO2 is a reasonable proxy for ventilation in public spaces, but I wonder how precisely that correlates with risk of infection when said space is a crowded supermarket and you're waiting in a checkout line with lots of unmasked people on every side of you. It seems quite possible that CO2 levels could be quite reasonable and there still be some #COVID or other nasties floating in the air. For now I'm going to err on the side of caution while grocery shopping.

Sheldon Aug 7, 2023

@BruceMirken you're right. All things are relative here. What we have here are degrees of risk, not degrees of safety.

The reason why I'm asking people who got stuck on conceptualizing risk in social distancing terms to drop it is not because all risks are equal.

The person right in your face is definitely a more potent risk, but if we're playing just the numbers game, only a handful of people can be in your face, but hundreds of people can be close enough to infect you if the air quality is poor. Yet people mostly look at what's in front of them.

Even during heavy spikes in 2020, in most places, at any given time there were fewer than 1 out of every 100 people who were likely to be highly contagious. Chances of being face to face with that 1 in 100? Small, especially if the symptomatic ones self quarantine or try not to get too close to anyone. Chance of ending up in the same room? Quite high.

That's the point here and some people who are trying to balance risk with reward need to understand that.

Oblomov Aug 7, 2023

@sysop408 @BruceMirken the good thing with ventilation and the CO2 proxy is that it's one of those things we would benefit from even if COVID wasn't an issue (a similar thing hold for washing hands, BTW, good hygiene practices transcend the specific ailment). So it's good to learn more about the specifics of COVID transmission, but it's also good that good practices are kept in mind and good habits reach as far and wide as possible.

TransitBiker Aug 7, 2023

@sysop408 @BruceMirken unfortunately for us survivors, the early strains of the NCOV2 virus were very non-contagious compared to the current stuff circulating. Indoor air concentrations of things. Definitely more of an issue now. The main reason why there were so many cases and deaths in 2020 is because A: horrible patchwork of response. B: No vaccine. And C: Healthcare overwhelmed.

TransitBiker Aug 7, 2023

@BruceMirken @sysop408 if you are wearing a proper respirator or elastomeric filtration facepiece, you should be totally fine in most of these conditions as long as your filter does not get wet or damaged.

acm Aug 7, 2023

@TransitBiker just be sure not to breathe out any water vapor!

GhostsheetZ Aug 7, 2023

@sysop408 produce gives off CO2. I’m not surprised Trader Joe’s had a lower rate because it generally has less produce. Either way I’m not a scientist and don’t take my word for it.

TransitBiker Aug 7, 2023

@Ghostsheetz @sysop408 their stores are also proportionately smaller. The produce section is approximately the same ratio.

Jeri Dansky Aug 7, 2023

@sysop408 I've also been pleasantly surprised by my Aranet readings in my local supermarket and drugstores. I still mask, but I'm less worried than I would have been otherwise.

Sheldon Aug 7, 2023

@jeridansky I'm wearing a mask for the forseeable future too. I decided to start doing this to gather data points to help me decide how to navigate the next phase of the pandemic and (hopefully) eventually to fewer precautions.

I've been most pleasantly surprised readings were so low in the restaurants that I've gotten takeout orders from, but I guess I shouldn't be too surprised once I think about it. Kitchens are inherently messy and smelly so even before we consider that they have to pass HVAC inspections, every restaurant's air flow is already being influenced by the needs of the kitchen.

It's not going to be this year, but I have hope that I'll be able to go enjoy a restaurant again.

What kind of readings are you seeing at grocery and drug stores?

Jeri Dansky Aug 7, 2023

@sysop408 I haven't checked recently, but I was getting 490-610 at the drugstores, 633 at the grocery store. Also 692 at the Apple store!

I get great readings at my dentist and periodontist because I've trained them to open the window in the room I'll be in. (I'm fortunate that they are both in buildings with windows that open.)

TransitBiker Aug 7, 2023

@jeridansky @sysop408 the dentist that me my girlfriend her kids go to the dentist that my mom goes to all use aerosol capturing machines in each patient room and they have N95 masks on all of the staff and air purifiers throughout.

Jeri Dansky Aug 7, 2023

@sysop408 And yeah, I'm still doing takeout or well-spaced outdoor dining. I'd love to feel OK about eating in a restaurant, but I can't see that happening any time soon.

TransitBiker Aug 7, 2023

@sysop408 During the very beginning of the pandemic at Trader Joes, they had their ventilation system basically cranked all the way up, and you could tell that they were mixing outdoor air with their air-conditioning air. You could actually feel the air flow in the store. Sadly, as time went on, we realised that we needed to do curbside or delivery to reduce risk. Trader Joes does not offer either of these things, so they were the last store I went shopping in.

Michael Helm Aug 9, 2023

@sysop408 This is fascinating & I need to start doing this. Why did you choose this particular #aranet4 CO2 monitor - there are a bunch of different ones & I don't know what I'm choosing from. Obviously non portable ones are useless so I can exclude them no matter what their quality.

PedestrianError

@sysop408 That might be the best ventilated Trader Joe’s in the country. I took my Aranet4 to a bunch of grocery stores a few months ago and all except TJ’s were in the 600-900 range, but the best reading I got (early morning) in a TJ’s was 1175 and it was usually 1300-1500… enough CO2 to measurably reduce cognitive function even if you’re not worried about COVID.

Sheldon Aug 12, 2023

@PedestrianError I want to go back and try that one again because that didn't seem right to me. It was in a new-ish building though and it was a TJ's right from the start as opposed to one that was stuffed into a vacant box. I need to also try other TJ's too.

Also these are all in suburban spaces. A packed TJ's for me is probably hold my beer TJ's in Manhattan.

@BegoniaArizona Aug 7, 2023

@sysop408 Wash your hands anyway. Wash them early and often. The flu can be spread by surface contamination, and the world has more antibiotic resistant bacteria any ever. WASH YOUR HANDS FOR REAL, AND mask plus go for as much ventilation and air filtering as possible.

Sheldon Aug 7, 2023

@BegoniaArizona By all means, do wash your hands, but just don't think that's how you're going to dodge getting Covid and yes mask as often as you can.

I don't push that because that's going to lose a lot of people. This is about pushing harm reduction and convincing people to improve ventilation is the most effective harm reduction method we have.

@BegoniaArizona Aug 7, 2023

@sysop408 I work with both babies and with the elderly. Hand washing definitely saves lives; same with those who are immune compromised. Also, good ventilation is essential for health and minimizing Covid spread, agreed. You are so right!

Steve | Father of 2 Aug 7, 2023

@sysop408 this is very informative and helpful. Thank you so much for sharing! We are having a flu season in Jakarta right now, but this time it’s a bit strange. Because we have so much phlegm and the sickness can last for 7-14 days. Since nobody is doing a swab test anymore, I’m just suspecting this is another wave of mutated covid. Since it’s been 3 months since the last wave ended.