Mastodawn

Sheldon Aug 7, 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

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.

@pineywoozle ‘s #3WordNote

@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.