the horizon - something you see very rarely with the smog that usually
envelops the capital. The silhouette of the Gherkin, Tower 42,

I lived in London for nearly 7 years and I don't really have any memories of
'smogs' except once, and that was during a heatwave in August 1997. It was
the photochemical variety.

On the whole London has reasonably good air quality given that it is a large
city. I was involved in a few studies regarding air pollution in London
(with the UPRC) and the most insidious form was the invisible PM10s from
bus, lorry & taxi diesel engines (this was before electrostatic
precipitators were widely fitted to large diesel engines). Using SEM
(electron microscopy) I studied these particulates that were captured using
masks that were worn by courier cyclists. I also did a study looking at the
particulates from passive smoking in pubs. The latter had air pollution in
the order of magnitudes greater even than the most polluted street in the
City.
________________
Nick.
Otter Valley, Devon
83 m amsl
http://www.ottervalley.co.uk