Along with daffodils and blossom, air pollution is a regular feature of spring in western Europe. Often these events are hard to notice in our everyday lives, but they have an impact on our health. For example, particle air pollution in spring 2014 was estimated to have resulted in 1,649 UK deaths.
This year, the London mayor’s alerting service issued warnings on 23 March and air pollution was also mentioned in weather forecasts. Air pollution then reached the top of the UK government’s 10-point scale across London and the south-east. Other badly affected areas, with scores of eight and nine, included eastern areas of England and parts of the north-west.
One starting point to control spring pollution is to understand what it is made of. For most of the last century, air pollution particles had to be collected on filters each day and it took weeks to do chemical analysis in laboratories. Now, three university-run air pollution “supersites” are conducting chemical analysis in real time. These are located in Manchester, Birmingham and London as part of the UK Clean Air Programme.
Springtime pollution is often dominated by particles that contain ammonium. This comes from gases given off by the large amounts of fertiliser and manure that are used at this time of year, combined with pollution from industry and traffic. Carbon particles, both soot and more complex compounds of carbon and other elements, also add to the mix.
Dr James Allan, from the University of Manchester, said: “Particle pollution was certainly high during March, but most of it (if not all) was made out of things like ammonium nitrate, ammonium sulphate and carbon compounds. The carbon-containing particles typically come from vehicle exhausts, wood burning, cooking and reactions between air pollution and sunlight. These are all things you would expect from pollution sources from within the UK and mainland Europe.”
Dr David Green, from Imperial College London, said: “The highest concentrations were characterised by large contributions from traffic, industrial and agricultural sources. This was a more intense episode than we normally experience but the combination of pollution emissions, easterly winds and relatively low temperatures can result in these elevated concentrations.”
Early data from Prof William Bloss, from the University of Birmingham, also shows the dominance of agriculture, traffic and industrial pollutants, along with particles from wood burning as well as tyre, brake and road wear.
It is clear from the data that our air pollution laws need to encompass many more sources than they do at present.
