AQESHOW - Abstract

Abstract Information :

Recent advances in air quality monitoring have resulted in new sensor systems that have the potential to provide an informative low-cost addition to reference methods. Such systems allow air pollution monitoring to be performed at a lower cost and with a higher spatial density than is possible with the current reference methods. They also allow for new source apportionment and calibration methodologies, when coupled with spatial information, to provide a much better understanding of an individual’s or group’s exposure to air pollutants. This new technology is being implemented by a wide range of users, from those involved in research studies employing sensor systems in hybrid networks to smaller scale users carrying out citizen science projects of local interest to communities. The sensor systems are based upon several principles of operation, including: • electrochemical for NO2, NO, SO2, CO and O3; • light scattering optical particle counting for PM10, PM2.5 and PM1; and • non-dispersive infrared (NDIR) for CO2. European wide standardisation to underpin such measurements, which might be suitable for regulatory reporting, has been slow in development due the need to accommodate the complexity of low-cost sensor performance. For example, the European Standardization body, CEN, only recently published a Technical Specification for gas sensors and another for particle monitors is expected for the end of 2024. The UK Department for Environment, Food and Rural Affairs (Defra) commissioned the National Physical Laboratory (NPL) to develop the document titled “PAS 4032: 2023 - Selection, deployment, and quality control of low-cost air quality sensor systems in outdoor ambient air - Code of practice”. The project scope involved holding a stakeholder conference with manufacturers of sensors and sensor systems, potential users of data from air quality monitoring networks, atmospheric modellers, academics, local and central government, and other end-users. The draft document was then reviewed a number of times by an invited scientific steering group and went out for public consultation, in order to maximise its usefulness to the air quality monitoring community. This presentation discusses the highlights of PAS 4023 and its key findings in terms the quality assurance (QA) processes needed to generate fit-for-purpose data from these novel sensor systems.