The London Metropolitan area has 76 air quality monitoring sites. The London Air Quality Network (LAQN) provides hourly updates of all their monitoring stations on their website. The LAQN classifies their pollution concentrations according to Defra’s Air Pollution Index system which ranges from 1 to 10 with 1 being low and 10 being very high. For the day of March 15 from 12:00am to 1:00am GMT most of the stations have an index level of around 1 or 2, some 4 and 5, and 6s and 7s. LAQN classifys an index of 1-3 as low, 4-6 as moderate, 7-9 as high and 10 as very high. The two stations that have a level 7 index are the Kensington and Chelsea – North Ken location and the Greenwich and Bexley – Falconwood FDMS location. In the Kensington and Chelsea – North Ken site they have a nitrogen dioxide air pollution index of 2, ozone index of 1, PM10 particulate of 4, PM2.5 particulate of 7 and a sulphur index of 1. PM2.5 and PM10 have potentially adverse health effects. They are small enough that they can get into the lungs. The other monitoring sites that have relatively high overall indexes, mainly have high particulate indexes with some having low indexes of other pollutants. From the monitoring sites that I had viewed, it seems like London’s biggest air pollutant is particulates. On their website they also post health warnings when the index is moderate to high, the LAQN advises those at risk, such as people with lung or heart problems, to refrain from or reduce any strenous activity, especially outdoors. For the general public at high levels, they recommend those who are experiencing sore eyes, cough or sore throat to avoid physical activity, especially outdoors.

London air quality website: http://londonair.org.uk/LondonAir/Default.aspx