Development of a low-cost sensing platform for air quality monitoring: application in the city of Rome

Air pollution in urban areas is a problem of complex nature and one of its principal characteristics is the variability of pollutants concentrations even at short distances from main road arteries. Nevertheless, the common approach for air pollution monitoring is by means of fixed stations, which are expensive, complex and provide low spatial resolution data, as they are low density deployed. These stations satisfy legislative requirements but do not provide data about local gradients of pollutants concentrations that can be significant for health protection: space-time variables are increasingly important to adequately characterise urban air quality. A possible solution to increment spatial resolution data in a city is by means of low-cost sensors, which are small and portable. Although these sensors do not allow the same accuracy and precision as certified analysers, they are increasingly used and tested all over the world and have the potential to integrate regulatory air pollution monitoring stations and promoting community engagement. In this paper LILI-1, a prototype of a low-cost air quality platform, is presented. It allows measuring meteoclimatic parameters and concentrations of principal air quality pollutants (NO2, O-3, PM10 and PM2.5) by means of electrochemical and optical sensors. LILI-1 has been tested in the city of Rome and compared with certified analysers, showing very encouraging results for all the monitored pollutants. It has also been used by mounting it on a bicycle and showing its ability to increment spatial resolution and obtain distributed data throughout the city.