Gerard Swan, 30, engineer, from Dublin
It's still not as bad as LA, but it's getting there. At least catalytic convertors and unleaded petrol are helping on some private cars, but when I see a taxi puffing along I think it's totally unregulated. I don't notice it except when I'm driving: you can't have the windows down in traffic.
Samir Dave, 21, computer programmer
I've been coming to London for over 30 years and the haze is a good deal worse, but only in the centre. The fogs used to be atrocious; you never get smoky sickly fogs now like you did then. I do feel it in my throat when I come here. Compulsory measures would help; all cars should have convertors.
Peter Hodges, 63, marine consultant, from Kuwait
I find all roads leading out to the West - most of all the A4 - absolute stinkers. It's young children who are being particularly affected. I like my car but there are too many in London and not enough efforts are being made to control the numbers. It's a national issue that isn't being dealt with seriously by the Government.
Sarah Scott, 33, researcher
My mother's always telling me how bad the air was in the Fifties; you couldn't see your hand in front of your face. But to me it's worse now than five years ago. Sometimes I can't breathe properly. Soon I'll start wearing a mask.
Harriet Thody, 29, bar worker/artistReuse content