Like most UK cities, London suffers from traffic-related pollution, but the sheer scale of the area, combined with a dense road network and tall buildings, means that central London appears to be one of the UK's most polluted areas. It is the key field where the legally binding limits set by the EU are not met. When it becomes trapped between buildings, or in the local area more broadly, particularly during still weather, pollution may build up in London.
We did extensive research on air quality in London. We have read and heard expert opinions on this issue. We met other organizations and groups that are also fighting the problem of clean air. Some are governmental; others are public. Everyone's cause is common - fresh air for all Londoners. During our research, we came across an E.ON campaign that aimed to measure the purity of the air in London, more precisely in the City with a machine in the lungs' shape. That is where our idea came from.