Explore knowledge & action
Explore real-world cases, scientific research and creative work that show the impact of citizen science.
Cases & stories
40 storiesInsights, stories and updates from the CitiObs community
Story300 Students, 9 Schools, One Mission: Monitoring Greece’s Air with AirLimnosĀ
AirLimnos is an initiative which was born by Web2Learn, a research and development company specialising in digital education, and has joined the…
StoryA Look Back, to Start the New Year
Itās 2025 and that marks the start of the third year of CitiObs! We have had an amazing two years working together…
StoryBeyond Ambient Monitoring: Why Personal Exposure Reveals What Regional Air Quality Misses
The value of activity-based exposure monitoring through the use of wearables isn't just understanding - it's empowerment. When individuals see their actual…
StoryBreaking Barriers in Environmental Monitoring with the Low-Cost Sensor Toolkit
Environmental challenges are growing concerns for communities around the world. Citizen participation in monitoring efforts has become a powerful way to address…
StoryBreathing Better, Together: Marking the International Day of Clean Air with CitiObs
Every breath we take connects us to our communities, to the places we live, and to the quality of the air that…
StoryCan Citizen Science bring wonder into science?
Dive into the thoughts of CitiObs' Coordinator NĆŗria Castell
StoryCitiObs takes action – working with creatives for positive change
In CitiObs we value co-creation and co-design. This means that in the development of our tools and toolkit we not only work…
StoryCitizen-led interventions to reduce noise by the Frontrunner case in Barcelona
Since November 2023, the Front Runner Case (FRC) in Barcelona has been thriving! Insights gathered during the Citizen Observatory onboarding workshop were…
StoryCitizen Observatories in Educational Institutions of Mykolaiv. What Air Quality is Relevant for Ukraine Today
Local measurements are becoming part of a broader citizen science network, while educational institutions are joining European environmental monitoring efforts. This work…
StoryCitizen Science in Action: Highlights from the CitiObs Study Visit in Brussels
In October 2025, CitiObs reached an important milestone. During the European Week of Regions and Cities ā one of Europeās largest gatherings…
StoryCitizen Science in Ukraine: Monitoring Air Pollution Amidst WarĀ
The ongoing war in Ukraine is not only a humanitarian crisis but also an environmental one. Fires, destruction, and explosions have significantly…
StoryCleaner Air Directive in Europe needs citizen scienceĀ
The entry into force of the new European Ambient Air Quality Directive has opened new horizons for improving the quality of the…
StoryCo-Creating Resilient Cities: Citizens, Data & Participatory ActionĀ
Three European projects - CitiObs, CLIMAS, and Empower-Citizens - are coming together to demonstrate how citizen science, participatory methods, and collaborative innovation…
StoryEmpowering Communities: Citizen Science and Water Quality Monitoring in MykolaivĀ
In Mykolaiv, Ukraine, CitiObs is actively integrating citizen science into the research efforts of pupils and students. Ongoing projects include monitoring atmospheric…
StoryEmpowering Policy with Trusted Citizen-Generated Air Quality Data
As Europe races toward its Green Deal goals, high-resolution data and timely environmental intelligence have never been more crucial. Yet traditional monitoring…
StoryExpanding the CitiObs Alliance: 30 New Citizen Observatories to shape urban environmental action
In spring 2025, the CitiObs took a significant step forward by welcoming 30 new Alliance Cases (ACs) to our growing community of…
StoryExploring the CitiObs Citizen-Led Toolkit
Our consortium partners, Jessica Carmen Guy and Ćscar GonzĆ”lez from Fab Lab Barcelona | IAAC share insights on the process of the…
StoryFILTER: A Tool for Making Citizen Air Quality Data More Reliable and Usable
Over the past decade, low-cost sensor (LCS) networks for air quality monitoring have surged across Europe. However, despite their growing popularity, LCS…
StoryFrom 213 Proposals to 25 Projects: The outcomes of the CitiObs x Distributed Design Open CallĀ Ā
Between May and June 2026, CitiObs and the Distributed Design Platform opened a call inviting artists, designers, makers, and creative collectives around…
StoryFrom low-cost community sensors to better air quality maps
Air pollution can vary sharply from place to place, both over a city and an entire continent. A busy intersection, a sheltered…
StoryFrom Reference Stations to Hybrid Networks: Designing Monitoring Systems Fit for 2030
For decades, air quality monitoring followed a familiar logic: install a handful of high-precision reference stations in key locations, collect data, and…
StoryHyperlocal, Real-Time Air Quality Data: Turning Transparency into Public Value
Annual averages have long been the currency of air quality reporting. A city either meets its limit values or it does not.…
StoryIdentifying local challenges and fostering collaboration with Citizen Observatories in Barcelona
In this post our consortium partners Milena Calvo Juarez and Oscar Gozalez , Fab Lab Barcelona delve into the dynamic knowledge exchange…
StoryIndicative Air Quality Measurements in Europe: What the 2024 AAQD Really Enables
Air quality is no longer a peripheral environmental topic. It is a compliance challenge, a publicāhealth priority, and increasingly a political pressure…
StoryJoin the CitiObs Alliance Citizen Observatories & Citizen Science Initiatives Across Europe
Weāre excited to announce an Open Call for Citizen Science Initiatives & Citizen Observatories across Europe to join CitiObs as Alliance Cases.…
StoryMapping effects of industrial emissions in Kristiansand
Our consortium partner Karin Ekman engages with residents of FiskĆ„tangen, Kristiansand, in a Mutual Learning Workshop to explore the achievements, obstacles, and…
StoryMapping Inclusion Together: Dutch and Flemish Citizen Observatories Meet in EindhovenĀ
On a bright Wednesday morning in April, fifteen people gathered at Sectie-C ā a vibrant cultural and creative community hub in Eindhoven…
StoryNavigating Citizen Observatory success: understanding stakeholder participation Dynamics
In this post, our consortium partners Kelsey Wentling and Uta Wehn, IHE Delft, elaborate on the intricacies of stakeholder participation dynamics in…
StoryReflecting on the First Mutual Learning Workshop in Athens
There is power in coming together, sharing knowledge, and working collaboratively towards a common goal. As we move forward, we are inspired…
StoryRotterdamās journey towards cleaner air through Citizen Science
Consortium partner Eline Verhoeven reflects on Rotterdam's first Mutual Learning Workshop
StorySmall Sensors, Real Questions: What Indicative Monitoring Is and Why It Matters
Local measurements are becoming part of a broader citizen science network, while educational institutions are joining European environmental monitoring efforts. This work…
StoryTAPIS: A Simple Web Tool for Analyzing Citizen-Generated Data
Citizen observatories and communities collect valuable environmental data - but making sense of this data can be tricky, especially if you're not…
StoryThe CitiObs Knowledge Platform: A New Hub for Citizen Science
Citizen science projects create a wealth of data, tools, and experiences. But this knowledge often remains scattered, making it hard to learn…
StoryThe Power of Mutual Learning in Citizen Observatories
Consortium partner Joao Paulo Tavares highlights the significance of CitiObs' Mutual Learning Workshops
StoryTurning environmental data into better decisions: the CitiObs Decision Support System
Environmental data is increasingly available across Europe. From air quality measurements to weather observations, cities and institutions collect vast amounts of information…
StoryWe need more people to lobby for cleanĀ air:Ā key takeaways from theĀ CitiObsĀ Citizen Science DialogueĀ on air quality and healthĀ Ā
On 26 May 2026, CitiObs brought together over 50 participants from all over the world to participate in the online Citizen Science…
StoryWelcoming Fellow Initiatives in 2026
2026 marks the final year for the CitiObs project but rather than slowing down, we are ramping things up by welcoming 50…
StoryWho decides what is measured and acted on, and who is left behind
Consortium Partner Margaret Gold reflects on the foundations for equality, diversity and inclusion being laid in the project during the first half…
StoryWho has colour?
Within the scope of the CitiObs project's focus on equality, diversity, and inclusion, Consortium Partner Andrea Reyes Elizondo investigates the complexities associated…
StoryWhy Dense Sensor Networks Matter: From Data Gaps to Decision-Ready Air Quality Insights
Air quality is no longer a background environmental issue. It is a compliance challenge, a publicāhealth priority, and increasingly a political pressure…
Art & creative practice
20 projectsExploring our environment through art and design
Featured projectClimate BabesAir Chimes
A participatory project in Castelnuovo di Porto, Italy, using wind-chime-inspired installations to gather residentsā and commutersā memories, reflections and sensory experiences of local air quality.
Commissioned projectAir Synthesizer
Wu Siou Ming is developing a sound installation that translates air-quality readings into changes in harmony, rhythm and texture.
Featured projectAndrea Farah GaetaBarrios en Resistencia
A collaborative mapping platform documenting neighbourhood businesses, local stories and community life in the Canary Islands through participatory walks, oral histories and audiovisual storytelling.
Commissioned projectBinary Loom
KateÅina KovĆ”ÅĆÄkovĆ” is developing a moving textile installation that responds to air-quality data, with each strip representing a sensor location.
Featured projectNoufa ShabeerBreaking the Loop
A walk-through installation using architecture, sound and movement to explore environmental change, taking visitors through three stages centred on home, disruption and renewal.
Featured projectJea Kyong SimBreathing Paper
A project using wearable hanji paper garments as material records of air pollution, bringing together changes in the paperās appearance, participantsā photographic diaries and local air-quality data.
Featured projectGabriella KissBreathing Routes
An art project in development combining walking, sensory observations, air-quality measurements and collective embroidery to create a shared textile map of urban air.
Commissioned projectClimate Arts Lab
Morris Mburu brought artists and Indigenous knowledge holders together in the Mt Kenya region to develop songs, poetry, paintings and photographs from…
Featured projectDusts InstituteDusts Catcher Kit
A low-cost, open-source kit for collecting and examining airborne dust. Designed for workshops, schools and public events, it invites people to investigate their surroundings through shared observation.
Featured projectOscar Ryan OumaEnvironmental Memory Maps
A community-led project in Busia, Kenya, combining storytelling, photography and participatory mapping to document environmental change around Lake Victoria through local memories and present-day observations.
Featured projectHanju SeoHOMI
A sensing project using a low-cost LiDAR device to record farming movements in 3D. It explores how agricultural workers can document their contribution and retain ownership of those records.
Commissioned projectHow Are You Really?
RĆ³za DeĆ”k works with anonymous messages left in public space. Her proposed installation brings selected texts onto hanging fabric panels, where visitors…
Featured projectOlivanta MwendaMaking Air Visible
A proposal for low-cost air-quality sensing, community mapping and green-barrier prototypes in Mukuru, Nairobi, involving local youth groups and community organisations.
Featured projectLI JiwenMoss Walk
An open-source digital project exploring mosses and urban microclimates. It proposes community walks and mapping to build a shared digital artwork from observations of moss in the city.
Featured projectGerardo Cruz & Luisa Tovar MĆ©ndezNERVADURA
A project in development using sensor-equipped, moving objects to explore local environmental conditions in Valencia, with plans for community-built devices and an audiovisual response to the collected data.
Featured projectMarĆa Paz Miranda GonzĆ”lezSalineros del Nilahue
A proposed collaboration with salt workers, combining environmental observations, historical records and collective textile art to document local knowledge and socioenvironmental change.
Featured projectVictoria PhamSoil Song, Issue 01: Wilding
A planned digital journal bringing together art, environmental research and storytelling. Its first issue, Wilding, explores ecological futures and the relationship between urban life, communities and the natural world.
Featured projectShalini NatarajanThe Air We Remember
A proposed textile archive combining cotton cloth exposed to Bengaluruās air with residentsā audio reflections. The collected textiles would form a patchwork installation linking material traces of pollution with personal experiences.
Featured projectAnoushka Pednekar & Amrutha Sai KannanThe Handbook of Hope
A proposed project with Mumbaiās fishing communities, combining traditional songs and performance with community-led environmental observations to document changing coastal conditions and local knowledge.
Commissioned projectWhat Does the Air Say?
Marcus Smith is developing a community radio and podcast series about air quality in Bristol. Interviews with East Bristol residents form part…
Scientific publications
11 publicationsResearch outputs and scholarly contributions
PublicationA scalable framework for harmonizing, standardization, and correcting crowd-sourced low-cost sensor PM2.5 data across Europe
The article introduces a scalable framework designed to harmonize, standardize, and correct crowd-sourced low-cost sensor PM2.5 data across Europe. By addressing inconsistencies…
PublicationDaily high-resolution surface PM2.5 estimation over Europe by ML-based downscaling of the CAMS regional forecast
The article presents the S-MESH (Satellite and ML-based Estimation of Surface air quality at High resolution) framework for estimating daily PM2.5 concentrations…
PublicationData, dialogue and infrastructure: the benefits of eight years of Samen Meten
The article summarises eight years of the Samen Meten initiative by the Dutch National Institute for Public Health and the Environment (RIVM),…
PublicationData fusion of sparse, heterogeneous, and mobile sensor devices using adaptive distance attention
The article presents a novel method for integrating diverse environmental sensor data to improve spatial predictions. The authors propose an adaptive distance…
PublicationDelineating the contours of citizen science: Development of the ECSA characteristics of citizen science
This paper explores how to better understand and define citizen science, a research approach that involves public participation across many fields. Because…
PublicationEstimating surface NOā concentrations over Europe using Sentinel-5P TROPOMI observations and Machine Learning
The article presents a novel approach to estimating daily surface NOā concentrations at 1 km resolution across Europe. Using the S-MESH framework,…
PublicationEvaluating the role of low-cost sensors in machine learning based European PM2.5Ā monitoring
The article presents an extension of the S-MESH (Satellite and ML-based Estimation of Surface air quality at High resolution) framework that integrates…
PublicationEvolving trends in application of low-cost air quality sensor networks: challenges and future directions
The article reviews recent developments in low-cost air quality sensor networks, covering applications such as mobile and drone-based monitoring, data fusion, and…
PublicationOpening science to society: how to progress societal engagement into (open) science policies
The article explores the complex interplay between species traits, environmental factors, and ecological interactions shaping biodiversity patterns. Through a robust analytical framework,…
PublicationPast and present marine citizen science around the globe: A cumulative inventory of initiatives and data produced
The article examines 1,267 marine citizen science initiatives, highlighting their growth, geographical distribution, and focus areas. It underscores the role of citizen…
PublicationTransboundary particulate matter, photo-oxidants, acidifying and eutrophying components
This report presents EMEPās activities and key findings for 2024, covering air pollutant emissions, measurements and modelling across Europe. It assesses trends…