Aira Go · Field Recording

Marathon Day
Air Quality

Harry Foster · London · 26 March 2026 · 351 readings
93.4
Peak µg/m³
11.4
Day avg µg/m³
0.9
Min µg/m³
11h
Recording
351 PM2.5 readings · 26 Mar 2026
Route
Home — SW12 8BW
08:00 – 09:25 2–93 µg/m³
Aira Go warming up indoors, then tube platform exposure
Northern line → Jubilee line
09:26 – 10:00 20–33 µg/m³
Clapham South → London Bridge → Bermondsey
Marathon spectating
10:00 – 11:40 6–19 µg/m³
w3w: summer.ruled.cares · roadside, 1hr 40min
Walk: Tooley St → London Bridge → Blackfriars → Waterloo
11:40 – 12:00 3–7 µg/m³
South bank west, cross London Bridge, Upper Thames St, Blackfriars Bridge south
Duke of York, Rathbone St
12:30 – 13:06 1–4 µg/m³
~1hr, then Northern line home to Clapham South
Home SW12 — return
13:14 – 19:01 0.9–6 µg/m³
Very clean all afternoon
PM2.5 over time
Peak 93.4 µg/m³ on tube. Falls to under 5 µg/m³ through afternoon.
WHO 24hr guideline: 15 µg/m³ — exceeded during the tube journey from 08:12 to ~10:08
0–5 Good
5–10 Moderate
10–25 Elevated
25–50 High
50+ Very high