“Citizen science has the power to close one of the world’s most urgent data gaps in addressing global air quality challenges”
– Dr Bridie Schultz, Director, teachSTEM Ltd.
Air pollution is responsible for 1 in 9 deaths worldwide. It has been linked to chronic and deadly diseases such as cancer, heart disease, pneumonia, and other adverse health outcomes. According to the Pollution and Health Progress Update Report, it is the fourth leading cause of global mortality, claiming nearly 9 million lives each year. Out of these deaths, more than 90% occur in low- and middle-income countries.
A 2024 report by OpenAQ reveals that 36 percent of countries currently lack the capacity to monitor PM₂.₅. This is an alarming data void in the face of a major health threat. UNEP has shown its commitment to strengthening air-quality governance globally by establishing the Global Air Quality Cooperation Network, under the direction of the United Nations Environment Assembly (UNEA) resolution 6/10. The network aims to strengthen international collaboration on air pollution. Despite this and many other great initiatives, monitoring remains uneven, especially in under-resourced regions. Without accurate data, countries cannot effectively address air-pollution-related illnesses, nor track progress toward public health goals and their sustainable development targets. Citizen science steps in to complement these systems, not as a replacement, but as a powerful force that expands coverage, democratizes data, and engages people directly in protecting their right to clean air.
In Kibera, Nairobi, a community-led initiative monitored air pollution around the Missing Link #12 road construction project. Local community members were trained and equipped with low-cost sensors, which enabled them to capture baseline air quality data. This process provided evidence about dust and emissions and increased awareness, empowering residents to discuss health risks with local authorities. Data became a bridge for engagement with local authorities rather than confrontation. In London, the Breathe London Community Programme distributed free calibrated sensors to 60 community groups between 2021 and 2023. Community members were allowed to choose where to place the sensors, ensuring that the data reflected lived experience. The result was not just better data coverage but a genuine influence on city policies. The programme provided a blueprint for equity-driven monitoring by integrating scientific rigor with grassroots participation.
In Europe, the grassroots initiative Sensor. Community started in 2016 with 300 sensors for monitoring particulate matter in Germany and currently has a network of over 10000 active sensors monitoring air pollution in Europe. In the Netherlands, the Dutch National Institute for Public Health and the Environment (RIVM) is integrating the data from Sensor.Community and runs the “Samnen Meten” (Let’s Do It Together) programme, which formally incorporates citizen-science data into the official national air quality network. In Norway, the Meteorological Institute is using validated citizen science data to assess the performance of European air quality models (uEMEP). These examples show that citizens are already collecting data that, after validation, complements the high-grade national monitors. Another powerful example is the “CurieuzeNeuzen” (Curious Noses) initiative, which began in Antwerp in 2016 and expanded to Flanders. Thousands of residents measured nitrogen dioxide levels outside their homes, creating one of the largest citizen science air quality datasets in Europe. The project not only led to behaviour change by encouraging people to reconsider transport choices, but it also influenced political debate in Antwerp, demonstrating how citizen science air quality monitoring evidence can shape governance. It enabled municipalities to rethink the design of streets, traffic management, placement of monitors, and priorities for intervention.
The NASA GLOBE project is another good example of how citizen science is bridging data gaps. GLOBE was a founding member and developer of the interoperable citizen science dashboard, Mosquitodashboard.org, an idea that emerged from the CSGP’s Global Mosquito Alert. The dashboard serves as a model for how multiple sources of data can be viewed and accessed. Through the GLOBE Program, citizen scientists will soon be able to monitor their air quality using a new PM2.5 monitoring protocol. This protocol will allow users to connect their own PM2.5 small sensors to GLOBE’s worldwide GIS database of environmental data. The system will be interoperable with other international data sources, allowing the integration of large citizen science datasets for global use.
These case studies are only a few examples of the many worldwide citizen science initiatives; they show that citizen science is not experimental but is credible, scalable, and already proving its worth. Citizen science is increasingly recognized as essential to achieving the Sustainable Development Goals (SDGs), particularly SDG 3 (Good Health and Well-being), SDG 11 (Sustainable Cities and Communities), and SDG 13 (Climate Action). By providing inclusive and locally relevant data, it ensures that no community is left behind in the global effort to improve air quality. Low-cost sensors indeed vary in performance, and communities may need support to interpret results, but these are design challenges, not fatal flaws. Through initiatives such as the Citizen Science Global Partnership’s Air Quality Community of Practice (CSGP AQ CoP), practitioners are building solutions such as developing calibration protocols (e.g. FILTER), training trainers, and working with bodies like CODATA and the UN Statistics Division to ensure data interoperability.
“Citizen science has the power to close one of the world’s most urgent data gaps in addressing global air quality challenges. Scientists can collaboratively empower communities to measure their own environment by providing them with the skills and knowledge to develop agency in creating impactful, local solutions. Through our work establishing Citizen Science Corners in Kenyan schools, teachSTEM is helping students and teachers use simple tools to collect, understand, and act on local air data. This form of community-led evidence will be the first step toward cleaner air and more equitable environmental decision-making.”
— Dr Bridie Schultz, Director, teachSTEM Ltd.
The UN can play a pivotal role as a convener and enabler by helping in the establishment of global principles for integration, providing support and funding for community-led initiatives, and promoting citizen science as part of the broader strategy for sustainable development. As UNEA-7 prepares to advance solutions for a resilient planet, citizen science should be recognized as a critical enabler, not as a substitute, but as a complement to regulatory monitoring. By embedding citizen science and community-driven data into global frameworks, the UN can foster inclusive science, strengthen accountability, and accelerate progress toward clean air for all. Championing citizen science at UNEA-7 is not just an option but an opportunity to ensure no community is left behind in the pursuit of environmental justice and sustainable development.
“Citizen science doesn’t replace official air quality monitoring; it multiplies its impact. High-agency local actors are often better positioned to spot what formal systems can miss. And, in the best scenarios, when these community efforts can join forces with institutional ones, the results can be faster, fairer, and more effective.”
— Christa Hasenkopf, EPIC Chicago.
The challenges of scaling citizen science are real—short-term funding, government skepticism, and uneven global infrastructure for data validation and integration—yet these are precisely the obstacles that international collaboration is best equipped to overcome. The UN has a unique role to play as a convener, enabler, and protector of community-led efforts. By integrating citizen science into multilateral environmental agreements (MEAs) implementation, advocating for equitable financing, embedding inclusive approaches into global frameworks, and creating pipelines that allow the integration of citizen science data with official data, the UN can help ensure that everyone has the right to breathe clean air. Air pollution is not just an environmental issue; it is a justice issue, a health issue, and a human rights issue. Citizen science is already proving that solutions are stronger when people and institutions work together. The path forward is clear. We need to integrate, scale, and ensure that in the quest for a healthier planet, no one is left behind.