Press release – Open platform hackAIR maps current air quality in Europe’s cities

Open platform hackAIR maps current air quality in Europe’s cities – powered by citizens and smart technology

Citizens can use the app and low-cost sensors to generate their own measurements of air quality to enrich official data, and find out how to avoid and reduce particulate matter pollution

Press release – 8 February 2018

Today, hackAIR launches its apps for iOS and Android, connected to an online platform at, where citizens in Europe can check the air quality in their neighbourhood. In turn, everyone can improve the data from official sources with their own measurements, for instance by simply uploading a photo of the sky with their smartphone.

With air pollution being the number one environmental concern of European citizens and the number one environmental cause of illness and death in urban centres, hackAIR provides actionable information on the most important type of air pollution: particulate matter pollution. Particulate matter pollution is a complex mixture of extremely small particles in the air, which are easily inhaled.

Around 90% of Europeans living in cities are exposed to levels of air pollution deemed damaging to human health. Whilst the damaging impacts of particulate matter pollution are widely recognised, official air quality data show significant gaps and are often difficult to access.

The hackAIR platform aims to make that data readily available and improve the official datasets by combining them with measurements from users. They can take photos of the sky, use a piece of cardboard with petroleum jelly, or build their own microcomputer sensor in an afternoon.

Many Europeans rightly worry about air quality: how clean is the air I breathe, when I live near a major road, airport or industrial zone? The hackAIR platform gives them the answer, and helps them to contribute their own measurements to make that answer better, more relevant and actionable,” says Evangelos Kosmidis, Physicist and Founder of DRAXIS.

The hackAIR service is location-based and real-time, offering users a map-based interface to the data available on the air quality in their neighbourhood. With that information, they can find areas with clean air for relaxation and sports, and which areas to avoid because of high pollution levels. Citizens with concerns over air pollution can also use the platform to get better informed and involved in the discourse to improve air quality, locally and on a larger scale.

hackAIR offers four ways for users to contribute their own air quality data:

  1. They can submit photos of the sky using the hackAIR app. An algorithm gives a rough estimate of air pollution levels.
  2. They can build a simple cardboard sensor that uses the discoloration of petroleum jelly to get an estimate of the amount of particulate matter pollution.
  3. hackAIR provides manuals and workshops to build stationary and portable microcomputer air quality sensors. These sensors are cheap, easy-to-build and provide high-quality data.
  4. Experienced users can submit and access data using an online application programme interface (API).

In the coming year, hackAIR is organising a series of workshops in the pilot countries Germany, Norway, Greece and Belgium to raise awareness and train people on air quality, how to build sensors, and how to use the resulting information.

Air pollution is the environmental issue that Europeans worry about the most. But they do not feel sufficiently informed about the issues, and its impact on their health in their country. With the app, the workshops and the sensors, hackAIR aims to empower them to make better decisions based on better information,” says Arne Fellermann, BUND/Friends of the Earth Germany.

The app and platform

The app can be downloaded for iOs and Android from

The platform is accessible at

About hackAIR

hackAIR is a collaboration of six European organisations working on air pollution,  environment, technology, citizen science and research.

The partners are DRAXIS (Greece), NILU (Norway), CERTH (Greece), BUND (Germany), Vrije Universiteit Brussel (Belgium) and ON:SUBJECT (the Netherlands). The Democritus University of Thrace, the Technological Educational Institute of Athens and CREVIS contribute as third parties affiliated to DRAXIS Environmental S.A.

hackAIR is supported by the Horizon 2020 programme on ‘Collective Awareness Platforms for Sustainability and Social Innovation’ of the European Union under grant agreement number 688363.

More information

Panagiota Syropoulou, project leader:, +30 697 900 35 12
In Germany: Arne Fellermann – Bund für Umwelt und Naturschutz Deutschland:, +49 176 810 366 72
In Norway: Hai-Yung Liu – Norwegian Institute for Air Research:, +47 638 980 48; Sonja Grossberndt – Norwegian Institute for Air Research:, +47 63898245
In Belgium: Carina Veeckman – Vrije Universiteit Brussel:, +32 2 629 16 65
In the Netherlands: Wiebke Herding – ON:SUBJECT:, +31 61 55 073 66
In Greece: Panagiota Syropoulou –  DRAXIS Environmental S.A.:, +30 697 900 35 12

Update from the hackAIR team (October 2017)

From ordering material, debugging mobile apps and writing tutorials: we’re getting ready for the launch of the hackAIR platform. What is happening right now in Thessaloniki, Oslo, Amsterdam, Berlin, Athens and Brussels?

Eleftherios Spyromitros-Xioufis (CERTH)

“CERTH is currently working on ways to increase the amount of data that enters the platform. In addition to collecting geotagged sky-depicting images from Flickr, we now also collect non-geotagged images and try to infer their locations based on the image metadata. Our evaluations suggest that the approach works surprisingly well, being able to accurately estimate the geolocation of a significant percentage of non-geotagged images. We also have added more data sources: In addition to the PM measurements from governmental sources, we have recently started to collect measurements from sensors.”

Gavin McCrory (VUB)

“The last 6 months have been a busy period for us at VUB! We’ve been bringing the ambitions of both pilots in Norway and Germany together with engagement lessons learned from air pollution projects, domain experts and over 400 citizens. In September, we developed our engagement strategy for hackAIR, which will guide and support pilots over the next year and a bit. Alongside this, we also developed the evaluation framework and behaviour change strategy for the hackAIR project. We’ll be presenting some of our lessons learned at the Internet Science conference (in Thessaloniki, Greece) next month. We’ll continue to explore channels to illustrate the results of our research, both online or in person; if you have any suggestions or ideas for how we could do this, please let us know!”

Hai-Ying Liu (NILU)

“At NILU we are doing lots of testing! Building up and testing the hackAIR sensors in the lab, testing the first version of the hackAIR web, the mobile app, and the hackAIR platform. The testing results will shared with hackAIR developers for update. In addition, we are preparing information and dissemination materials in Norwegian to contact potential participants. We are also preparing materials for the pilot training and testing for the upcoming case study in Norway, Germany, Athens and Brussels.”

Panagiota Syropoulou (DRAXIS)

“At DRAXIS we are coordinating the work of all partners so that we are ready to ignite the pilot activities within the following months. We are in regular contact with external experts in the fields of air quality, citizen science, gamification and user experience to ensure that citizens will enjoy the hackAIR experience and that our pilots will be successful. The development team is currently fine-tuning and testing the platform so that we will be ready to go public.”

Wiebke Herding (ON:SUBJECT)

“The ON:SUBJECT team is working behind the scenes to prepare for the launch of the hackAIR platform. In the past months, we’ve built a completely new website for the project, drafted tutorials, shot videos and reworked hackAIR’s visual identity. We’re also working on a set of workshop materials that you can use to learn about hackAIR and build your own air quality sensors. We’re not quite ready to show you any of this, but we can’t wait!”

What we know about air quality

Between May and July 2017, the VUB research group SMIT conducted a multi-language survey to explore the awareness and behaviour of citizens in the context of air pollution, as well as the interest to measure it. After the first data collection, close to 400 people from Norway, Germany and other countries gave their input, including 261 in German, 64 in English and 47 in Norwegian.

We found that levels of awareness about the causes of air pollution are high amongst our sample, who regard traffic, emissions from industry and burning from household activities as the three main sources of particulate matter pollution. Awareness levels about the associated impacts of air pollution were similarly high – the main adverse effects identified include threats to health, effects on nature and lower quality of life. However, citizens indicated that they are less informed about which individual steps they can take to reduce air pollution.

Our results pinpoint that people are generally curious about air pollution, and have an interest given their proximity to urban areas. This is also in line with the finding that people also regard pollution at the city level as a more clear and present problem than nationwide or neighbourhood specific pollution. We learned that traditional media channels such as newspaper, radio and television remain central sources of information about air quality. The value of digital channels also emerged, however, with one in four people benefiting from social media, websites and online platforms.

Importantly, our results show that citizens want to be engaged in policy dialogues and workshops around the topic of air pollution, and are interested in viewing and measuring data in real-time. They see value in connecting to related projects around air pollution, but also show that there are several challenges around the technical skills involved to build, measure or understand the data generated by low-cost sensors and our mobile application. For the next year, these points will underpin our approach to community-based engagement, focusing on real-time air pollution, support and training, and learning by doing in workshops.

If you would like to find out more about the hackAIR survey, feel free to contact Carina Veeckman from VUB-SMIT on

Wearable air quality sensors

Kick-off meeting for the VERTIGO artistic residency on the 17th of October 2017 at DRAXIS premises in Thessaloniki. Guests: Emily Groves, representative of the VERTIGO project, Ling Tan, artist from Umbrellium, and Sarah Unwin, from FutureEverything that will co-finance the artistic work.

hackAIR was selected by VERTIGO as one of the research projects that will welcome an artist to work with them. The VERTIGO STARTS Artistic Residencies Program organises collaborations between artists and research and development projects in the field of Information and Communication Technologies (ICT).

The project that the artist will work on is called “Pollution Explorers”. It is a participatory project consisting of a set of wearable tools co-created with the hackAIR community, using the hackAIR platform to help citizens making sense of the complex issues around air pollution. It combines wearable technology, IoT, citizen participation and crowdsourcing and is intended to help investigate personal responsibility in air quality issues among citizens. With these technologies the artist will try to explore ways to measure people’s subjective perception on air quality and compare it with actual measurements of air pollutants.

The project will run from November 2017 until December 2018 and it will engage 2 groups of participants to co-create the wearables and monitor the local air quality. The scope of the project is to identify the correlation between citizens’ perception on local air quality and real air quality levels. From this residency, hackAIR will achieve greater visibility and engagement of citizens.


Air Sensing Roundtable: Initiatives for air quality and participatory sensing

The main challenges for air quality & participatory sensing include reliability of data, good communication with public authorities and strong community relations. These were the hot topics discussed by participants of the Air Sensing Roundtable webinar on 26 September.

With this webinar, hackAIR provided a platform for participatory sensing initiatives to discuss their approaches, experiences and challenges. What can we learn from each other? How can we join forces to increase citizen participation in air quality sensing?

Three initiatives shared their actions and learnings:

  • CAPTOR | collective awareness platform for tropospheric ozone pollution
  • | sensor toolkit to measure air quality with citizen science
  • hackAIR | open technology platform to access, collect and improve air quality information

In an in-depth discussion, participants active in the field talked about their main challenges and concerns. These include

  • Reliability, data validation and calibration;
  • Communication and relation with public authorities; and
  • Community relations.

Ideas for collaboration were pitched, links to related initiatives were shared and the path for further streams of dialogue for 2017 and 2018 was cleared. hackAIR will use this input to strengthen its launch in January 2018.

Are you a professional working on and interested in air quality and participatory sensing? Join our email list for the Air Sensing Network for more exchange and mutual learning.

Practice report: Testing the hackAIR sensors

Figure 1. hackAIR WIFI shield connected to the SDS011 sensor

In spring 2017, a group of engineering students from the Oslo and Akershus University College of Applied Sciences (HiOA) evaluated a first prototype of the hackAIR home sensor and compared the measurements with reference equipment. After overcoming the initial struggle of getting the prototype to work, they conducted two measurement campaigns: one inside the lab environment, and one in the foyer of the school. For that purpose, they also created a 3D-printed case for their sensor.


Figure 2. LAS-AIR II
Figure 3. Aerotrak particle counter

Compared to the reference equipment (a LAS-AIR II aerosol particle counter and an Aerotrak particle counter), the students found that measurements differed slightly, though within a reasonable correlation. Increases and decreases in air pollution were picked up correctly. In general, the PM10 measurements turned out marginally less exact as the PM2.5 data.


Figure 4. hackAIR prototype case with SDS011
Figure 5. PM2.5 correlation of the LAS-AIR II and SDS011 in the hallway



When using the sensor in the casing, the responsiveness of the hackAIR sensor decreased: That is why the final design of the hackAIR casing will need to ensure proper airflow towards the sensors.

Figure 6.  Measurement devices in the hallway of the first floor in P35 of HiOA

Thanks a million for this exploration, Lisa Marie Rickerts, Carter Barkley, Ryan Beacham & Leyre Ortiz García.

Ensuring quality measurements with the hackAIR sensing toolkit

With hackAIR, you can contribute to better information about air quality in your neighbourhood using a number of different tools. But how good are our data? What can we really say about air quality?

The general principle: official data as a foundation

To calculate the overall air quality map for a city, hackAIR supplements official air quality measurements with user-generated data. The outcome is a continuous map of estimated air quality. Similar to the weather report, we calculate probabilities and estimates for locations in which there are no official measurements. As our models are based on reference measurements, these will always dominate in case they contradict with user-generated data.

When you zoom in to a neighbourhood, you will see the individual measurements that have contributed to the overall estimate – both from official data and other sources.

Sky images to estimate air quality

When you take a picture of the sky, the specific shade of blue you see will vary depending on the air pollution. Using this principle, hackAIR calculates the so-called aerosol optical depth of publicly available and user-submitted images to estimate air quality, taking into account the specific location and time at which the picture was taken. Unfortunately, it is impossible to directly compare these measurements to exact PM10 or PM2.5 values. Instead, the hackAIR app is showing pollution categories (from bad to very good).

  • We mapped the air quality in Thessaloniki using sky photos and we compared these estimations with official measurements in the city. According to the results, our method is able to characterize the aerosol variability within urban centres and identify hotspots.
  • We are currently organising campaigns where we collect a quite big number of sky images taken from different devices so that we examine how the type of the camera affects the quality of the results.

Open hardware sensors

Testing the hackAIR sensors

Both hackAIR open hardware devices use the same component for air quality measurements: The SDS011 sensor. Generally, this component is seen as “the best sensor in terms of accuracy ” for low-cost electronics thanks to its larger fan and laser-based design. However, this does not mean the sensor is as accurate as official reference stations. A scientific evaluation of the SDS011  concluded that measurements are comparable for average humidity – high humidity and temperatures can cause less accurate measurements. The second version of the hackAIR home sensor will thus include a temperature and humidity sensor so that we can balance this effect.

  • The manufacturer of SDS011 sensor, Nova Fitness Co. Ltd., reassured us that the sensor is factory calibrated
  • We have placed some hackAIR sensing devices next to official stations and we are comparing their results.
  • We are testing the validity of the hackAIR sensing devices in laboratories using the Dylos Air Quality monitor.

Update from the hackAIR team (March 2017)

Update from the hackAIR team

Things are moving in the background: the different parts of the hackAIR platform are slowly taking shape, and we’re busy planning for pilots and user engagement. What is happening right now in Thessaloniki, Oslo, Amsterdam, Berlin, Athens and Brussels?

Eleftherios Spyromitros-Xioufis (CERTH)    

“We are working on the image analysis module. We are already processing more than 10.000 images daily – efficiency is a big topic at the moment. We have also started displaying them on a map to see how the data is distributed geographically.”

Ilias Stavrakas (TEI)

“We have completed the communication interfaces for the hackAIR open hardware sensors. Our next step is to make the sensor more user friendly and collect user feedback. We’re also still working on the interface with the smartphone app.”

Ioulia Anastasiadou (DRAXIS)

“We are currently developing and testing the main features of the hackAIR mobile app using the new UI designs. Once this is complete, the same features will be implemented for the web – so that the two of them are in line. At the same time we are integrating the different parts of the system (sensors, fusion, image analysis).”

Paulien Coppens (VUB)

We are further exploring the topics of citizens’  engagement and behavioral change related to air quality. We are now creating specific engagement strategies for hackAIR, for which a literature review on engaging citizens for citizen science has already been done. Next step: conducting expert interviews to learn from other experiences in the field.”  

Philipp Schneider (NILU)

“We are working on statistical methods for combining the observations made by the hackAIR users with other data sources such as those from air pollution models. By doing so, we will be able to offer the hackAIR community spatial information about air pollution, even at locations where no recent measurements are available. The core mapping algorithm has already been developed and we are currently working primarily on the communication interface with our observation database and on testing the method with the first incoming real data.”

Inge Jansen (ON:SUBJECT)

“In the communications team, we are preparing for the launch of the hackAIR platform. This means a lot of internal conversations: What materials do we need? Which audiences do we address first? What is the timeline? In addition, we’re building links with stakeholders and related projects, and happily present this newsletter.”

Arne Fellermann (BUND) 

“Air quality has been a fiercely debated topic in Germany for the first months of 2017. Many German cities, in particular the larger urban regions have problems keeping their air quality limit values. BUND is involved locally in many of the cities in question and also runs a court case against the city of Hamburg for not doing enough to clean the air. hackAIR is a great project to raise awareness and involve citizens, so we can’t wait for the pilot project to happen in Germany.

“With BUND we are currently involved in the national discussion on urban air quality. Many German cities, in particular the larger urban regions have problems keeping their air quality limit values and come under increased pressure by court cases to come up with effective plans to reduce air pollution. In February, the city of Stuttgart, Germany’s air pollution capital with its specific topographic situation and a high volume of motorized traffic in the inner city area, had announced that from 2018 onwards it would only allow the newest EURO6 cars into the inner city, prohibiting access for older cars, whenever there is a so-called “Feinstaubalarm”, and alert for exceedances of particulate matter levels. This alert was introduced in 2016 to create awareness and trigger emergency responses. Two other cities, Düsseldorf and Munich, recently had court rulings requiring them to act within a short time-frame to implement effective measures, including bans of dirty cars. These court orders mean that Germany might see more drastic bans for especially Diesel vehicles. BUND is involved locally in many of the cities in question and also runs a court case against the city of Hamburg for not doing enough to clean the air.”

hackAIR’s social media monitoring tool

Keeping track of conversations and finding good people to follow on social media can be hard. Within hackAIR, this task has now become easier: CERTH has developed an easy-to-use web-based tool that enables real-time monitoring and analysis of a variety of popular social media platforms with open APIs (Twitter, Facebook, Google+, YouTube). This helps us discover online communities and accounts related to air quality and track the impact of our dissemination activities on social media.

An air quality oriented collection
An air quality oriented collection

The tool is configured to keep track of content that is posted around specific keywords and/or accounts of interest. In the context of hackAIR, we use keywords and accounts related to air quality but in principle, the tool can be used to monitor any type of keywords and accounts (e.g. the name of a brand and a number of accounts that often post messages related to this brand). Once specific sets of keywords and accounts (“collections”) have been specified the tool starts pulling related content from the social media platforms on a regular basis (every 15-30 mins) and creates a browsable stream of social media items (“feed”).

The feed view also enables filtering of the items by keyword, source(s) (e.g. show only Facebook and Google+ posts), language, topic (facilitated by text clustering methods), type (media/text) and date range. The items can also be ranked by recency (i.e. the most recent posts first) or popularity (e.g. post with the largest number of shares first). In addition, it is possible to filter redundant items (items with nearly identical content).

Browsing through a feed of social media posts around air quality
Browsing through a feed of social media posts around air quality

The feed view provides a useful means of discovering trending and popular social media content related to air quality topics and entities. However, the real power of the tool is the capability to provide quantitative views and statistics about the monitored content. This is exposed through the “dashboard” view, which is illustrated below. The dashboard consists of several “widgets”, i.e. visualization elements that depict a specific piece of information in an easy-to-grasp way. The first row of widgets concerns the activity and impact measurement of the monitored topic in terms of activity (number of posts), user base (number of users posting), reach (number of users reached) and endorsement (number of users liking the posted content). Another widget depicts the contribution of each social media source (Twitter, Google+, etc.) to the overall activity about the topic. A timeline widget illustrates the activity around the most important keywords over time. There are also two map widgets: a) a heatmap widget showing the levels of activity across the globe based on the location of geotagged posts (i.e. when users chose to share the location of their posts), b) a world map depicting the location of users (by geo-parsing the location field that users have entered in their public user profile page). Finally, there is a histogram widget that shows the most active users around the topic and a keyword bubble widget that depicts the most important keywords around the topic.

The tool source code is available on GitHub:
For more information contact: Manos Schinas ( or Symeon Papadopoulos (

Dashboard offering several statistics and visualizations around air quality.
Dashboard offering several statistics and visualizations around air quality


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