Widespread public interest in air pollution started as a result of the “Great London smog” of December 1952, which is thought to have caused over 4,000 premature deaths. As a result, legislation was introduced to try and reduce pollution concentrations, such as the clean air act of 1956 and the UK air quality strategy in 2000. This in turn has led to air pollution concentrations being routinely monitored on a daily basis, in both urban and rural environments. However, air pollution is not a single entity, and is instead a mixture of components. The levels of a number of these are routinely measured, including carbon monoxide, nitrogen dioxide, ozone, particulate matter (small solid or liquid particles such as dust) and sulphur dioxide.
The perceived health risks of air pollution and the availability of relevant data has resulted in a large body of research over the last 30 years. A large part of this research has investigated whether exposure to air pollution has an adverse effect on human health, and scientists have addressed a number of questions related to this issue, including:
- Which specific pollutant is bad for human health?
- How high do pollution levels have to get before it becomes bad for human health?
- How long do you have to be exposed to pollution before it becomes bad for you?
The other main area of air pollution research involves modelling the change in concentrations over space and time, rather than relating it to human health. Again this area of research has spawned a number of interesting questions for scientists to answer, including:
- How do you measure whether the trend in pollution levels has increased or decreased over time?
- How do you produce a map of the pollution concentrations across a city or country, with the aim of determining where the worse affected areas are?
- As numerous pollutants are measured at multiple points across most cities, how can you combine these data into a single summary to inform the general public.