Oxford City Council has been managing two AQMesh pods, supplied by Air Monitors Ltd, in order to monitor the impact the new Westgate centre is having on local air quality.
Urban air pollution
Urban air pollution is typically a variety of pollutants mixing at different rates depending on their source and local weather conditions within bust, built-up areas. Many small air quality sensors are often limited by the impact of these fluctuating temperatures and levels of humidity, but AQMesh has been carefully developed to withstand and compensate for the effects of complex environmental conditions.
Modern intelligent traffic systems are designed to move traffic in an efficient manner as well as reduce the environmental impact of traffic on nearby populations. This includes the effects of noise, particle pollution and gases.
Conventional air quality monitoring systems are often too large and complex to install in the locations where monitoring is necessary, such as junctions and interchanges as well as busy trunk roads. In this application, the absolute accuracy of the sensors is of secondary importance to being able to prove reliable trend information and the ability to be placed at multiple locations along major roadways.
AQMesh pods are an ideal solution for this type of monitoring as they are small and operate on battery power. Data is returned in near real-time to a web-based application in formats recognised by most traffic management systems. The trends can then be compared with traffic flow and meteorological information to allow traffic managers to better understand the conditions leading to pollutant excursions and thus how to minimise and prevent them in future.
Vertical pollution monitoring at different levels of a high rise building can reveal exposure of inhabitants to pollution and inform guidance about ventilation.
- Pollution reduces with height as pollutants disperse in rising air currents
- Normal dispersion can be altered in adverse weather conditions
- Abnormal dispersion is difficult to predict with computer modelling
- Taking real measurements can accurately monitor the changes taking place
- 3 AQMesh pods are co-located at street level for a short period to confirm they are reading the same
- 2 of the pods are then relocated at different heights with the remainder acting as a reference
- The pods can be compared to show the difference in measurements.
Street canyon effects
Air pollution is known to vary significantly across an area. Depending on the prevailing weather conditions at the time of monitoring, the concentrations of pollutant gases can vary from one side of a road to the other, as well as along the road and of course over time. Air modelling software faces many challenges in built up urban environments as the topography makes traditional dispersion algorithms less effective.
AQMesh can provide useful information in these applications. The pods are normally co-located in one position to ensure they are reading the same concentration and then dispersed around the area of interest.
Urban air quality monitoring case studies
Minnesota Pollution Control Agency (MPCA) has purchased fifty AQMesh pods to measure key air pollution gases and particulate matter across fifty different zip code areas.
On Sunday 13th May 2018, Cardiff Council organised a car-free day in the city’s central area. As a result of this event air quality monitoring data showed an average 69% drop in nitrogen dioxide (NO2) – one of the pollutants of greatest public health concern.
AQMesh has been used in a project at the Port of Kiel, Germany, to measure emissions of nitrous oxides (NOx) and fine particulate matter (PM) around its cruise ship terminal.
Following a successful evaluation phase in 2018, AQMesh small sensor air quality monitoring ‘pods’ have been selected for use in a project to control the ventilation of a road tunnel in the city of Marseille.
A new network of air pollution monitors has been installed to record emissions from cruise ships docking in Greenwich.