Modelling Partly to Blame for Air Quality Failures

On 2nd November 2016 the High Court ruled in a case brought by ClientEarth, that the UK Government’s plans to tackle air pollution are illegal. The judgement said: “the Secretary of State (for the Environment, Food and Rural Affairs) must aim to achieve compliance (with the Air Quality Directive) by the soonest date possible, that she must choose a route to that objective which reduces exposure as quickly as possible, and that she must take steps which mean meeting the value limits is not just possible, but likely.”

The judgement also said that “the Secretary of State fell into error by adopting too optimistic a model for future emissions.”

“This modelling approach is deeply flawed,” says Jim Mills, Managing Director of air quality monitoring specialists Air Monitors (UK). “It is well known that the major cause of air pollution in towns and cities is road traffic, and that diesel engines in particular are responsible for high levels of Nitrogen Dioxide (NO2) and fine particulates. As the VW scandal has highlighted, it is dangerous to rely too heavily on models that generate air quality predictions based on laboratory tests rather than real-world air quality monitoring data.

“In my view, past reluctance to create a higher density of monitoring points, as is common in many other countries, is short-sighted. It is certainly true that reference air quality monitoring stations are relatively expensive to install and maintain, but this ignores two major issues.

“Firstly, air pollution results in over 40,000 premature deaths every year in the UK and the Royal College of Physicians has estimated that this costs more than £20bn per year, which is just under 16% of the current annual NHS budget!

“Secondly, monitoring technology is improving rapidly; enabling better monitoring at a lower cost.”

New monitoring technologies such as ‘AQMesh’ dramatically improve the flexibility and relevance of air quality monitoring. As a low cost, small, lightweight, web-enabled device, an AQMesh pod can be placed in almost any location; recording air quality where it is most important. Pods can be quickly and easily installed at head height, next to schools, alongside busy roads, in car parks etc. As a result, air quality data can help government, local authorities and citizens to make decisions that protect health. Jim says: “AQMesh was not designed to replace reference monitoring stations; its purpose is to fill in the gaps; to help find pollution hot-spots and to check that remedial efforts are working.”

Over 150 AQMesh pods have already been installed around the UK and some were used to highlight London’s air pollution problems when ClientEarth took the Government to Court. On 17th October 2016 (the night before the Court case) the BBC strapped a pod to a bicycle and highlighted dangerous NO2 levels in a Newsnight programme during which a former advisor to David Cameron expressed the view that we do too much computer modelling and not enough actual monitoring.

Summarising Jim says: “The Government must now develop an effective plan to tackle air pollution; which is guided more by monitoring than modelling, and which is evaluated with real monitoring data. Clearly, the number of diesel vehicles in urban areas needs to be reduced and there are many ways to achieve this. Difficult political decisions lie ahead and further costs are inevitable, but a more comprehensive monitoring regime will improve the effectiveness of air quality management and enable the assessment of different improvement measures.

“Given the number of lives being lost to air pollution and the enormous cost to the NHS, it is clear that significant investment in monitoring and air quality improvement measures must be made immediately.”