Hmm good point - the bus stop I was thinking of is set back from a quiet road and is on the edge of a village green, so personallly I wouldn't worry here. I suppose though that this is an issue for urban gardening in general. Our local council has offered us a range of 'postage stamp' plots but most are exposed to quite heavy traffic. I wonder if there is any research on this? or even a simple test kit that could be used by urban community gardeners? Even so I think that accompanied by an info board it could be a great awareness raising/education tool - maybe even more so if the board included a warning that the plants were currently not for consumption due to pollution.

***I have also not added a subject title and have the same problem - do we need a 'subject box' when replying to a thread?
Still quite messy looking at the page (buttons on top of photos) also loads of space on the page which would be a waste of time and energy if following a long thread.

2nd post: just wondering why posts are not appearing in order - this is definitely via the reply button below Josiah's post

My 4th post - so what's happening is the original post stays at the top and then replies are appearing in reverse order (newest first) below that. In my view quite confusing!