The Close the Door talk at the City of London Forum for Transport and Sustainability in the Guildhall was a great way of discussing the issues around open doors on the high street with a range of influential parties from planners and investors through to residents groups. Perfectly timed with the Evening Standard leader "Pollution levels deserve far greater urgency" today, as it happens. It is a real matter of urgency to get over the message from the Kings College London/Imperial College research that closing doors onto the street significantly reduces exposure to harmful particulates in air pollution, while the issues around diesel exhaust are sorted out in the longer term. The City of London has been unfailingly encouraging and helpful to the campaign. Many thanks to Francesca Hobson and Simon Mills for today's opportunity.