ETC/ACM report no. 2018/21 - Low cost sensor systems for air quality assessment: possibilities and challenges

New low-cost technologies for monitoring air quality have enabled a number of projects by civil society or individuals, with the broad aim to assess the quality of air locally. This new source of information is emerging in a highly technical and thoroughly regulated area. We have to address both the technical and the social aspects of such projects, try to find scientifically appropriate ways to use the new information, and explain the differences between information obtained by different technologies. In this report, we would like to provide a practically oriented overview of use of low-cost sensor system technologies within the ecosystem of air quality monitoring and measurements. Sensing techniques are rapidly evolving. This ‘ever’ improving capability implies among other, that there is currently no traceable method of evaluation of data quality. Despite the efforts of numerous groups, including within the European standardization system, a certification system will take some time to develop. This has important implications for example, when comparing measurements taken in time, by different technologies or their versions. Fitness for purpose – why are we measuring or monitoring and how do we intend to use the information we obtain – should always be the main criterion for the technological choice. The report starts with an overview of elements of a monitoring system and proceeds to describe briefly the new technologies. Then, we give examples of how low-cost sensor technologies are being used by citizens. These examples are followed by reflections on how to provide actionable information. Having learned from practical implementation of sensor systems, we also discuss how the data from citizen activities can be used to develop new information, and finally, we reflect on developing low cost sensor systems monitoring on a larger scale.

02 Aug 2019

Air quality is enjoying popular interest in the last years, with numerous projects initiated by civil society or individuals that aim to assess the quality of air locally, aided by new, low-cost monitoring technologies that can be used by “everyone”. Such initiatives are very welcome, but in this highly technical and (in the western world) thoroughly regulated area, the professional community seems to struggle with communication with these initiatives, trying to reconcile the often highly technical aspects with the social ones. The technical issues include subjects such as monitoring techniques, air quality assessment methods, or quality control of measurements, and disciplines such as metrology, atmospheric science or informatics.

In this report, we would like to provide the reader with a practically oriented overview indicating the position of these new technologies in the ecosystem of air quality monitoring and measurement activities. Sensing techniques are rapidly evolving. This ‘ever’ improving capability implies among other, that there is currently no traceable method of evaluation of data quality. Despite the efforts of numerous groups, including within the European standardization system, a certification system will take some time to develop. This has important implications for example, when comparing measurements taken in time, by different devices (or different versions of the same sensor system device). Fitness for purpose – why are we measuring or monitoring and how do we intend to use the information we obtain – should always be the main criterion for the technological choice.

The report starts with an overview of elements of a monitoring system and proceed to describe the new technologies. Then, we give examples of how low-cost sensor technologies are being used by citizens. These examples are followed by reflections upon providing actionable information. Having learned from practical applications of sensor systems, we also discuss how the data from citizen activities can be used to develop new information, and provide some reflections on developing sensor systems monitoring on a larger scale.s to struggle with communication with these initiatives, trying to reconcile the often highly technical aspects with the social ones. The technical issues include subjects such as monitoring techniques, air quality assessment methods, or quality control of measurements, and disciplines such as metrology, atmospheric science or informatics.

We feel that the new technologies, while a disruptive change, provide many exciting opportunities, and we hope that this report will contribute to promote their use alongside with other assessment methods. We believe that increased understanding of technical issues we discuss will ultimately lead to better communication on air quality, and in its consequence, will enable further improvements in this domain.