Air pollution is a serious public health crisis which affects us all, but especially the most disadvantaged, and we need to act fast to prevent more harm, warns columnist Christina Okafor "Air pollution is by no means a great equaliser. It is a magnifier of inequality"Amir Hosseini by Christina Okafor Sitting outside at home, blue skies surround me – the perfect winter’s day. The birds sing. The leaves of the trees rustle. Traffic buzzes and hums – car horns, ambulance sirens, and low-flying planes.