Street-level London air pollution warnings coming via mobile phones   Animated sequence of nitrogen dioxide concentrations over the city of London during a high-pollution event that occurred on 15 November 2000. The major source of nitrogen dioxide pollution is road traffic, and the highest concentrations (deep red colour) can clearly be seen around the busiest roads during the morning and evening rush hours. High nitrogen dioxide concentrations may trigger asthma attacks, or cause breathing difficulties for those with lung complaints or heart conditions. This London pollution animation was produced by Cambridge Environmental Consultants (CERC), commissioned by Hackney Building Exploratory.   A cyclist in Central London wears an anti-pollution mask, 14 May 1998 as the British Government warned of a high smog alert over the next few days, due to the current heat wave hitting the Capital. Heavy city traffic is causing traffic fumes to be caught up in the still air and high ozone levels are forecast.   The YourAir Central London Air Quality Forecast is available via the internet, providing street-scale detail on pollution concentrations and any resulting health risks.   The YourAir Croydon Air Quality Forecast is available via the internet, providing street-scale detail on pollution concentrations and any resulting health risks.   PROMOTE and GMES     A detail from a global image shows the European mean tropospheric nitrogen dioxide (NO2) vertical column density (VCD) between January 2003 and June 2004, as measured by the SCIAMACHY instrument on ESA's Envisat. The scale is 1015 molecules/cm-2. Image produced by S. Beirle, U. Platt and T. Wagner of the University of Heidelberg's Institute for Environmental Physics. Release date: 4 November 2005