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

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

@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.