Guardian: It is a very ordinary weekday morning. I am taking my children to school, a 10-minute journey if the traffic is good, double that if it is not. A very normal checklist: sports kit, spare jumper and, of course, face mask.
It is eight oclock, the worst time of the day for pollution. Through the windows of the car pooled with a neighbour the smog is a thick yellow. The outlines of buildings, even trees, only a hundred or so metres away are blurred and vague. I check the air monitor readings...