Thank you for your kind comments Peter.

You’re right that relocating to a safer and cleaner environment is better than avoiding busy streets because there will always be residual contaminants practically everywhere in a big city. The problem is that many people cannot afford to relocate — perhaps because of their jobs or family or many other possible factors.

My suggestions about avoiding busy streets were really directed at these people with limited options. If you must live in a polluted city — or simply want to live in a polluted city — you are, at the very least, better off finding the least polluted routes for your journeys.

I wish you all the best.