V high particulate pollution in the Underground. There were some shock-horror articles a while back, and I did some research on it, not really coming to any firm conclusion. Origin is brakes, wheel on rail contact, electrical machinery, high density of people, etc. The actual nature of the particles in there is very specific, very different from other places. We don't really understand how bad it is for you, the nature of the pollution is probably more important than the number, given it is so different from the generality of surface pollution where we can say more is worse. On the fence article, Science Focus.Martin Y wrote: Sun Jul 23, 2023 5:39 pm .... personal air quality meter on his trip into town (displayed pm2.5 in microgrammes per cubic metre).
TL/DR: roads around his home measured 3-5. Central London, 4-6. Journey there by Underground 60-200+.
Probably very bad for you article, Cambridge Univ.
Another place where people fail to realise they are suffering very bad pollution is inside their car as they drive along. The car's fan sucks in exhaust fumes of their own vehicle and vehicles you follow. It's actually worse than riding a bicycle or walking along the same road.