Citizen science for air quality monitoring

By: Christer Ågren

People’s awareness of air pollution and the associated risks to their health has grown significantly over recent years, often informed by local or national campaigns led by non-governmental organisations (NGOs) as well as by media coverage. In some countries, groups of concerned citizens, often supported by NGOs, have taken authorities to court over air quality issues, and the courts have ruled in favour of the right to clean air in several instances.

A new European Environment Agency (EEA) report provides an overview of low-cost devices that citizens and NGOs can use to measure local air quality. The report presents successful examples of projects using simple low-cost devices to measure local air pollution levels, such as:

CurieuzeNeuzen Vlaanderen (Curious Noses Flanders), which was set up in 2018, has been labelled “the largest citizen science project on air quality to date”. The aim of the initiative was to provide a detailed map of nitrogen dioxide (NO₂) concentrations in Flanders (the northern region of Belgium), both in cities and in the countryside.

EEA CleanAir@School, a joint initiative of the European Network of the Heads of

Environmental Protection Agencies and the EEA that ran from 2018 to early 2020, in which participants monitored air quality around schools across Europe.

The Health and Environment Alliance (HEAL), as part of their “Healthy air, healthier children campaign”, ran a monitoring project using passive samplers and involving schoolchildren at 50 schools in Berlin, London, Madrid, Paris, Sofia and Warsaw. The results were published in 2019.

The EEA report also briefly explains how the different air quality monitoring devices work, summarises their reliability, and highlights the potential of such devices to address questions about air quality.

According to the EEA, this type of citizen science initiative can produce useful additional information about local air quality, and such information can be used, for example, to improve official air quality models that are used to estimate pollution levels. Results from monitoring can also help to identify suitable actions and measures to improve air quality.

Moreover, air quality monitoring projects often help to raise public awareness of air quality problems, which in turn – through public pressure – may result in local, regional or national decisions to introduce stronger measures to reduce air pollution. Increased public awareness can also incentivise changes in personal behaviour, such as switching from driving private cars to walking, cycling or using public transport.

The EEA points out, however, that various types of measuring devices each have different benefits and disadvantages, and users should be aware of their limitations. Although some devices are relatively reliable, low-cost sensors can for example, be sensitive to weather conditions or lack the capacity to measure very high or very low pollutant concentrations.

In the near future, the increasing number of citizen science initiatives focused on air pollution, coupled with new data digitalisation approaches, may represent a paradigm shift in the way that air quality is monitored, the EEA report states. A large network of low-cost sensors, combined with statistical analysis or machine learning, could complement the quality of the current official data and provide new pathways to obtain accurate, real-time information.

Christer Ågren

Source: EEA News, 12 March 2020 

 The EEA report “Assessing air quality through citizen science” can be downloaded at:

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