Adrian wrote:

MOST of London's major arteries go through (or very close to) well-off
areas.

This does not mean though that well off people are affected as much as
poorer people. I can't see that the Mile End Road is like the A316 through
Richmond in terms of housing density, street population, location of
primary schools and susceptibility.

One health impact is stroke - as this study says:

'Our focus was on proximity to roads and stroke mortality, but a striking
observation was the substantial association between socioeconomic
deprivation and stroke mortality in middle-aged people.'

http://stroke.ahajournals.org/cgi/co...aha;34/12/2776

E.