Citizens Sensing Emissions – First Results of a Citizen Science Project

According to the European Environmental Agency, bad air quality is Europe's most significant environmental health risk. SensEm is a citizen science project that involves citizens without scientific training in the participatory measurement and analysis of air quality in public spaces. The project should provide citizens with tools to understand their (social) environment and, ideally, help shape it sustainably. This paper will present the first results regarding the citizen science methodology development (process, (digital) toolkit, sensor design), the execution of the first use case, and the engagement with local citizens' initiatives and stakeholders in the German cities Berlin and Wiesbaden. It also gives an outlook on the next steps. A sensor kit was developed to measure the most critical air quality indicators (regarding the current pollution level): nitrogen dioxide, particulate matter, and noise, with available low-cost sensors. In addition to the sensors, a microcontroller was chosen capable of reading out the sensors and transmitting the data via Bluetooth or a Long-Range Wide-Area Network (LoRaWAN). A vital aspect of the housing design is removing non-essential features, such as screens and buttons, to enhance durability and resistance to vandalism. The sensors, initial methods, and workshop concepts were tested during the first pilot. A complete citizen science process was developed based on available guidelines and will be tried in upcoming use cases in Wiesbaden and Berlin. A (digital) annotated time-place map will be a central tool to collect contextual information and connect this information to the measurements to support the interpretation of the measurement results. Stakeholder interviews support the whole process of identifying for whom the data is relevant and how it could be used for different purposes (e.g., city planning). The first pilot showed the potential of joint interpretation with citizens, as they could contribute their knowledge of local conditions and thus provide additional explanations for the origin of the collected data. The most relevant finding from the first interview was that the data collected as part of citizen science projects can, at best, only supplement official measuring stations due to the high legal requirements. Nevertheless, data from citizen science projects could become more critical in the future in the form of indicative measurements in light of the current negotiations on a new (stricter) EU air quality directive.