I continue to be very excited about my new M2000 meter, and I brought it with me today to measure air quality during my commute and workday. Here's what I found:
| Time | Activity | CO2 (ppm) | pm2.5 ug/m3 |
|---|---|---|---|
| 8:00 | Left house | 426 | 2.9 |
| 8:15 | Davis station | 468 | 69.9 |
| 8:24 | Red line, new car | 802 | 29.3 |
| 8:36 | Kendall station, outside | 477 | 11 |
| 8:40 | Hallways, elevators, breakfast in cafe | 563 | 2.8 |
| 9:18 | Office, door open | 475 | 1 |
| 10:00 | Closed door | 514 | 1 |
| 10:31 | Open door | 553 | 1 |
| 11:02 | Team meeting, 14 people, ~15x30 | 1052 | 1 |
| 12:04 | Hallways, elevator | 686 | 1.6 |
| 12:10 | Lunch in cafe | 943 | 2.6 |
| 12:50 | Hallways, elevator | 763 | 2.1 |
| 12:57 | Office, door open | 537 | 1 |
| 2:02 | Closed door | 539 | 1 |
| 2:31 | Two people | 599 | 1 |
| 2:54 | One person, open door | 587 | 1 |
| 3:01 | Closed door, two people | 598 | 1 |
| 3:31 | Open door, zero people | 538 | 1 |
| 4:04 | Closed door, two people | 591 | 1 |
| 4:38 | Kendall station | 487 | 36.6 |
| 4:44 | Red line, old car | 953 | 21.6 |
| 4:56 | Davis station | 537 | 134.5 |
| 4:58 | Outside | 445 | 2.25 |
I spent most of my workday in my office, with the door open. I closed the door for meetings, either virtual or in person. The "zero people" at 3:31 is me going on a walking 1:1: with a report and leaving my meter behind at my desk.
Currently I wear a mask on the subway (and stations) and at work when I'm not in my office or a conference room with a small number of people. Based on these readings, it would be safe from a covid perspective to remove my mask in the subway station, but given the high level of particulate pollution I might as well leave it on.
(At this point I'm not wearing a mask because I think it would be directly harmful to myself or my family to get covid, but instead because the steps we would need to take to reduce the risk of infecting others once we knew we were infected would be very inconvenient.)