@ele-infos Yes, Italy has heavy industry, most of it in the north, with Milan the centre. You might be on to something! Although London is much bigger and has a massive, busy public transport system, but has a much smaller problem (so far), but will have higher humidity levels than Milan. Interesting...

@ele-infos Yes, Italy has heavy industry, most of it in the north, with Milan the centre. You might be on to something! Although London is much bigger and has a massive, busy public transport system, but has a much smaller problem (so far), but will have higher humidity levels than Milan. Interesting...