Indoor and outdoor air pollution is responsible for 6·5 million deaths worldwide per year. And this figure will continue to rise without urgent intervention.
In the UK, Public Health England estimates that human-made air pollution causes up to 36,000 deaths per year1. In England, the total cost estimate to the NHS and social care between 2017 and 2025 could be as high as £5.6 billion2 with 2.5 million new cases of disease by 2035.
Outdoor air pollution includes particulate matter (PM2.5 and PM10), nitrogen oxides (NOx), ozone (O3), volatile organic compounds (VOCs) and ammonia (NH3).
NOx generally comes from road and non-transport, energy industries and manufacturing and is generally a local issue near the source.
Surprisingly, transport only contributes around 12% of the PM2.5 that we are exposed to, while residential homes, small commercial units, and industry major sources.
PM2.5 can in fact be a very regional pollutant – where pollution caused in one country can be blown by wind into other countries.
Indoor air pollution is also an issue as both households and the workplace contain hundreds of pollutants – including PM2.5 and VOCs.
Studies of human exposure to air pollutants by the U.S. Environmental Protection Agency indicate that indoor levels of pollutants are generally 2-5 times higher than outdoor levels3 which is a concern given that most people spend about 90% of their time indoors4.
Air pollutants cause adverse effects in adults and children, and are linked to respiratory problems5,6, cardiovascular issues7,8, type-2 diabetes9, foetal growth10, low birth weight11, fertility rate12, dementia13, neuro-behavioural function14 and depression15,16.
VOCs, including formaldehyde, are used frequently in common household and workplace products, and are also released from furniture, carpets, upholstery, polishing, air fresheners, personal care products, smoking, heating, cooking and candle burning.
Vulnerability to the effects of air pollution is also dependent on socio-economic spatial factors with greater public health integration and collaboration required for improved air quality management policy and practice17.
Despite these alarming health statistics, people are generally not aware of the damages caused by air pollution, and most can’t be informed about actual PM levels unless they live close to an air quality monitoring station.
Until now, there have been just a handful of monitoring stations in Wales as part of the Automatic Urban and Rural Network (AURN). Their principal role is to supply data for compliance reporting.
Online air pollution forecasts also rely on modelled data which might be inaccurate at many locations.
Historically, accurate air pollution monitors have been extremely expensive but new sensor technologies have allowed development of a new generation of affordable monitoring.
The UK government have recognised this in their Clean Air Strategy 2019 and there is an agreed need for additional, low-cost, local but reliable monitoring25.
Ultimately, it is people who pollute, and it is also people who get negatively impacted.
Therefore, the real solution to reduce air pollution is awareness of how we pollute, where we pollute, and the changes that we can make by ourselves or together.
Particulate Matter – and why information is key.
The health impacts of air pollution, especially PMs, can only be reduced if people have access to information – that is, real-time, local, high quality air pollution data presented to them in a simple meaningful way.
Governments and local authorities can only act to reduce PMs if they know definitively where the sources are. Companies and agriculture can only take action to reduce PMs if they know what the background levels of PMs are in their locality and that they actually have a problem.
These are the reasons why we are installing our Think Air.
Our bespoke particulate monitoring network is low-cost, yet produces high quality, real-time data across the UK. This study presents the accuracy of our monitor – which has been fully evaluated against an AURN reference monitoring station – along with the data collated from a school in rural Wales.
Think Air – the PM2.5 and PM10 monitors driving change across the UK.
Think Air is low-cost air quality monitor that’s compact, versatile, and capable of LoRaWAN, 3G, wired or WiFi connectivity. It’s also equipped with a multi-sensor modu
lar unit that can integrate into existing Think Air networks.
The unit can operate across a wide temperature and humidity range in urban, rural and industrial environments.
The node offers options for extremely accurate PM2.5, PM10, PM1, NO2, NOx, NH3, CH4, and O3 measurements as well as temperature and humidity readings. Each unit can be powered via the mains or using a small solar powered unit.
Pollutant concentration data can be captured at a high frequency and averaged over 15 minutes, hourly or daily depending on need. Our ThinkAir unit is both simple and quick to install (Figure 1) with easy access for sensor maintenance. The sensor technology has been fully assessed against an AURN monitoring station to ensure air pollutant concentrations measured have high accuracy and low error.
Performance metrics for daily mean and hourly mean readings required by the ‘United States Environmental Protection (EPA) Performance Testing Protocols, Metrics, and Target Values for Fine Particulate Matter Air Sensors: Use in Ambient, Outdoor, Fixed Site, Non-Regulatory Supplemental and Informational Monitoring Applications’ guidelines, and recorded for the assessment period, are shown in Table 1.
Each Think Air monitor is rigorously calibrated prior to despatch within the factory and further tested in open air.
Data from a Think Air monitor is streamed live to an online dashboard to provide up-to-date local air quaity information (Figure 2). Data can be provided through simple reporting of an easy to understand air quality index or more comprehensive visualising of time series patterns of data.
is also mobile app friendly allowing users to check their air quality seamlessly at home, whilst travelling or at work.
Think Air – the UK’s largest non-governmental PM2.5 and PM10 monitor network.
In 2020, our plan was to roll out an entire ThinkAir PM monitor network right across Wales so that all citizens could have access to background, real-time data.
|Performance Metric||EPA||ThinkAir Monitoring Unit|
|Target Value||Daily mean|
|Precision||Standard Deviation (SD)||≤ 5 μg/m3||1.18 μg/m3|
|Coefficient of Variation (CV)||≤ 30%||14.4%|
|Bias||Slope||1.0 ± 0.35||0.94|
|Intercept||-5 ≤ b ≤ 5 μg/m3||-1.45|
|Linearity||Coefficient of Determination (R2)||≥ 0.70||0.98|
|Error||Root Mean Square Error (RMSE)||RMSE ≤ 7 μg/m3||1.35|
Our target was to install 50 monitors across urban and rural locations. This was completed at the end of April 2021 (Figure 3).
We are also installing monitors at critical locations in England, such as Hemingstone in Suffolk, that will allow us to measure PMs being blown in from the continent before it reaches Wales – an ‘early warning system’.
As our dataset keeps growing, we are able to combine air pollution data with meteorological data and use artificial intelligence to develop new algorithms for predicting future, local PM patterns – for people across Wales.
Our new Think Air PM monitors have proven to have high accuracy and can be deployed in both urban and rural environments.
Think Air monitors can be rapidly installed on any building, including schools, industrial units and sites, hospitals, care facilities, and at home.
We have rolled out a large PM Monitor Network at 50 locations across all counties in Wales covering different environments – and have now expanded into England, too.
To date, Think Air is the largest non-governmental particulate monitoring network in the UK.
The Network provides real-time and background levels of PM to allow organisations across Wales to build awareness of the air quality local to them from measured data as opposed to modelled data or no data at all.
Think Air monitors are already showing that rural and remote areas in Wales can have PM pollution equal to, or greater than, levels in large urban areas like Cardiff.
Our data and trajectory modelling in a case study showed that in 2020, when PM levels were very high in a village in Wales with no other air pollution monitoring available, it corresponded with fine particles being blown in from outside Wales, including the continent.
By expanding the network into England, we will be able to provide an ‘early warning system’ for these easterly winds blowing air pollution into Wales.