SheldonAug 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

Show threadSheldonAug 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

Show threadJeri DanskyAug 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.
Show threadSheldon

@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?

Aug 7, 2023 at 8:25amWeb
Show threadJeri DanskyAug 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.)

Show threadTransitBikerAug 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.
Show threadJeri DanskyAug 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.