(2) - “Environment, Health & Transportation - Motor Vehicles and Air Pollution”, International Bicycle Fund, referencing “The Environmental Impact of the Car”, Greenpeace, London, <http://www.ibike.org/environment/air-pollution.htm> , accessed December 2007 .

Motors contribute the following to the cocktail entering Londoners' lungs:
75 per cent of nitrogen oxides
83 per cent of benzene
77 per cent of particulates
53 per cent of volatile organic compounds
29 per cent of carbon dioxide
97 per cent of carbon monoxide.