Bridging the Gap: Smart Benches for Accessible Urban Air Quality Monitoring and Public Engagement in the Region of Attica

The rapid urbanization of modern cities presents significant challenges, with air pollution emerging as a critical concern for public health and environmental sustainability. In Greece, while the government collects extensive air quality data as mandated by the EU Directive 2881/2024 (recast of 2008/50, 2004/107), limited efforts are made to communicate this data to the public. The existing network of large monitoring stations is often inaccessible to the pubic and primarily serving scientists and policymakers.

Addressing this gap, the FAIRCITY (ATTP4-0360457) project—a collaboration between the National Observatory of Athens, the National and Kapodistrian University of Athens and the Greek Innovation Company Energy4Smart—introduces the “Smart Stations” an innovative solution incorporating public benches powered by photovoltaics, equipped with free charging sockets for people with electrical wheelchairs as well as other smart city sevices, with embedded low cost air quality sensors, designed to make air quality data accessible, timely, and engaging. This initiative not only aligns with global sustainability goals but also serves as a model for other cities seeking to improve urban liveability. The low-cost sensors embedded within the bench at a height of approximately 3 meteres above ground, were selected based on size, technology and price criteria to continuously monitor eight key pollutants: three fractions of Particulate Matters (PM₁, PM_2.5, PM₁₀), carbon monoxide (CO), carbon dioxide (CO₂), nitrogen dioxide (NO₂), ozone (O₃) and sulfur dioxide (SO₂).

The Smart Stations are deployed in open, public spaces (e.g., commercial areas, residential zones, parks), at a distance from major pollutant sources and in collaboration with interested municipalities of the Attica Region. Their aim is to record the local air quality and pollutant diurnal variations in order to highlight the sources responsible (i.e., Korydallos high NO₂, NO, PM concentrations from traffic) and estimate the population exposure. Citizens can walk up to these stations, sit down and instantly access critical information about their local air quality from digital displays that provide in near real-time the simplified Air Quality Index (AQI) along with health protection and other environmental infomation.

Preliminary results indicate that the diurnal variations of the monitored pollutants follow closely the local anthropogenic activities (traffic by passing the area, central heating, cooking). The pollutant levels are similar across the different municipalities, presenting peaks at different times depending on the type of area. The hourly AQI is mainly affected by larger scale events such as an extensive air pollution episode or dust intrusion event.