Air Quality Monitoring Scheme

Air Quality Monitoring in Calne for Particulate Matter (PM 2.5 & 10 microns). The video below explains more about particulate air pollution.

CALNE Community (Citizen) Science AQM Project

The Project Lead has started to build PM sensors in small qualities for individuals and for a Calne Town Council project to include seven local Schools. The first one was installed in November 2019 with more built and getting ready for installation. COVID-19 slowed down the project but we have starting to get going again (November 2021).

Are you technically minded? Students doing environmental, computing, or electronics studies, or just interested?

Want to help with this project? Get in touch


This Community Science led project was first mooted through our Town Twinning with German town Eningen-unter-Achalm, a few years ago. In 2019 the subject arose again at a Calne our Place (CoP) meeting, where it was decided to form a working group to discover the details of the project and with the intention of pursuing it to fruition.

Sustainable Calne endorses and supports this project and will keep these pages updated. Sustainable Calne will use the data to highlight areas of Calne where levels of PM are unacceptable in accordance with internationally set standards for PM pollution, that is, currently considered “safe” levels, relative to known health conditions.

The Air Quality Index (AQI) calculated from the monitors is according to the recommendations of the United States – see the DEFRA AQI table further down the page. There is general consensus on AQI.

This project with worldwide take up is based on low cost monitoring equipment which can be constructed relatively inexpensively. The equipment was devised as a Community Science Project by Open Knowledge Foundation (OK) Labs in Germany. The AQ Monitors currently measure concentrations of PM2.5 and PM10 in the atmosphere in real time. Data is streamed to a central database where it is supported by detailed graphical analysis and programmers APIs. Access is open to all participants and the resultant data to the general public across the world. The project is based on Open Source software and firmware.
Globally available information on the project.

You can read an lot more about the international project and even build you own. We have made a few small enhancements to the original design.

Sensor.Community maintains an English-language site for this project containing all you need to know to build your own.

It looks like there is a project to measure NO2 being considered. We will be keeping track of that.

Air quality data

Take a look at the live sensors across Calne

Take a look at these sensors across the world

You can also view the WAQI (Worldwide Air Quality Index) real time mapping which includes our sensor data.

Air quality index

Band Index Health message
Individuals at risk General population
Low 1 Enjoy your usual outdoor activities Enjoy your usual outdoor activities
Moderate 4 Adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms. People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion. Enjoy your usual outdoor activities
High 7 Adults and children with lung problems, adults with heart problems, and older people, should avoid strenuous physical activity. People with asthma may find they need to use their reliever inhaler more often. Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors.
Very High 10 Adults and children with lung problems, adults with heart problems, and older people, should avoid strenuous physical activity. People with asthma may find they need to use their reliever inhaler more often. Reduce physical exertion, particularly outdoors, especially if you experience symptoms such as cough or sore throat.

Project progress

Update: 6th November 2021

We have five AQ monitors installed so far – we need to install more in pollution hotspots around Calne. Three are currently in maintenance and will be returned to service soon. Two new monitors were demonstrated at the Eco Fest at the Town Hall.

Update: November 2020

We gave a presentation to UWE (University of the West of England Students on Environmental Studies Course.

We were invited to join a Salisbury AQ Group online meeting to share our project initiatives and answer questions. We have made some progress on Key Stage 2 AQ activities for Calne Schools

Update: October 2020

We have started working on a schools programme linked to Key Stage 2. We have a UWE Masters Student working with us on a Schools AQ initiative. We undertook a seminar for our student on the AQ Project accommodated at Calne Central.
This initiative has been halted due to COVID…

Update: November 2019

The Project Lead has started to build PM sensors in small quantities for individuals and for a Calne Town Council project. Three are currently installed in Calne (the first one on November 2019) with more built and ready for installation.

Further information on PM2.5

A 2012 DEFRA Report on the prevalence & effects of PM2.5 states: (you can read the whole report here)

Particulate matter (PM) is the term used to describe condensed phase (solid or liquid) particles suspended in the atmosphere. Their potential for causing health problems is directly linked to the size of the particles. A growing body of research has pointed towards the smaller particles, in particular PM less than 2.5 μm in diameter (PM2.5), as a metric more closely associated with adverse health effects than other metrics such as PM10 (particles with a diameter less than 10 μm).

A new measurement network was established in 2009 for PM2.5 using reference equivalent instrumentation. Data are now becoming available from this network to evaluate PM2.5 distribution and legislative compliance. However, there is a requirement to define the important rural background contribution to PM2.5across the UK. The relative lack of rural background sites, there are only three, restricts our ability to quantify sources of PM2.5. Additionally, there are limited measurements of PM2.5 composition in different types of location and in different areas of the UK.11. Evidence from urban sites and the limited number of rural background measurement sites indicates that regional (rural) background concentrations make a considerable contribution to the overall mass of PM2.5 in urban areas, accounting for around 60-80% of the background concentrations in the major urban areas of southern England. The regional background concentrations are dominated by secondary PM2.5, primarily as ammonium nitrate and ammonium sulphate, but also as organic particles. In the central and southern UK around 60% of the urban background mass PM2.5 is made up of secondary particles. Sulphate particles remain important, despite the large reductions in sulphur dioxide emissions since the 1980s.