By Richard Duffy
London is once again in the grip of another air quality crisis, although not one as dramatic as the Victorian killer fogs that used to blight our city. The 21st century problem is rather subtler, caused by invisible pollutants such as nitrogen dioxide (NO2) and microscopic particulate matter (PM). These are associated with a range of respiratory and cardiovascular diseases, and are especially problematic for people with lung conditions such as asthma and COPD, as well as the elderly and small children. It has been estimated that over 9,400 deaths in London can be attributed to these pollutants every year, with the major source being road transport (in particular diesel engines), though gas combustion and wood burning also play a role.
Rippers and pea soupers
[su_pullquote]Things went from bad to worse after the industrial revolution, and in the 19th century the city was notorious for the choking London fog, London particular or pea soupers.[/su_pullquote]
London has historically been a world leader in air pollution. Bad air has blighted the capital ever since burning coal became commonplace in the 12th century, resulting in Edward I (ineffectually) banning the fossil fuel in 1306. Things went from bad to worse after the industrial revolution, and in the 19th century the city was notorious for the choking London fog, London particular or pea soupers. A recurrent trope of Victorian literature, it provided atmosphere and symbolic weight in classics such as Bleak House, The Strange Case of Dr Jekyll and Mr Hyde, and Alfred Hitchcocks Jack the Ripper-inspired 1927 silent film The Lodger a Story of the London Fog.
Things came to a head in December 1952 when weather patterns trapped a thick cloud of smog in the city for several days in an event dubbed ‘The Great Smog of 1952’, directly causing around 4,000 deaths.
This led to the Clean Air Act of 1956, which created smoke free zones where only smokeless fuel could be burned. The journey to cleaning Londons air had begun.
London fog today
[su_pullquote align=”right”]In Lambeth the yearly legal limits for the number of times hourly NO2 levels can go above 200µg/m³ was exceeded in just five days.[/su_pullquote]
There is no level of PM that is not associated with negative health effects, and Londons air contains above WHO-recommended levels, although it is within EU legal limits for now. When it comes to NO2, however, it is far in excess of both. The London Air Quality Network, run by the Environmental Research Group at Kings College London, found that in 2014, 39 out of 67 monitoring sites were in breach of EU annual legal limits for NO2, with eight of these twice over the limit. The extent of the problem hit the headlines in January of this year, when it was reported that in Lambeth the yearly legal limits for the number of times hourly NO2 levels can go above 200µg/m³ was exceeded in just five days.
King Edward I banned the burning of sea-coal in London in 1272, after the “London fog” became a problem | Photo Courtesy: The New York TImesWhat’s being done
The Mayor of London has an Air Quality Strategy to address this crisis. This features many important initiatives such as the creation of an Ultra Low Emission Zone in central London, cleaning up the public transport fleet and providing a dedicated £20m fund for air quality projects at the local level. However, there remains a pressing need to accelerate this plan further, and many believe a challenge prize could be a very productive mechanism for doing so.
Cleaning Londons air is complex, possibly even a wicked problem. The complexity arises from the difficulty in defining the problem (pollutants and sources vary with time and place); that there is no single solution but multiple, diverse, hard to compare potential solutions; and because there is a large number of varied factors involved. Tackling the issue requires a mix of social, infrastructural and technological innovation.
The air quality problem in London is just one example of a global public health emergency, one of the most significant challenges of our era urgently requiring innovation and public engagement.