Author(s)

REBECCA CARUANA, ADAM GAUCI, MARVIC GRIMA, EMMANUEL SINAGRA, ALFRED MICALLEF

Abstract

Air pollution, especially airborne particulate matter (PM), poses significant risks to human health and the environment, yet air quality monitoring on the Maltese Archipelago remains spatially limited. This paper presents the concept and the gradual implementation of the first dense, low-cost PM monitoring network that covers Malta, Gozo and Comino, which utilises PurpleAir optical sensors capable of measuring PM_1.0, PM_2.5, and PM₁₀ concentrations, apart from some other meteorological parameters. The sensors are strategically being deployed in urban, suburban, and rural environments to generate high-resolution spatial and temporal information on air quality (especially concerning PM concentration), complementing existing regulatory monitoring infrastructure and addressing gaps in sparsely monitored areas. The network design incorporates co-location with reference-grade instruments and meteorological sensors to support calibration, validation and accurate interpretation of PM concentration measurements under local atmospheric conditions. All stations transmit real-time data to a publicly accessible online platform, enabling researchers, policymakers and the general public to visualise air quality conditions and assess short- and long-term variability. Despite inherent limitations related to sensor calibration and long-term maintenance amongst others, the network demonstrates the feasibility of establishing a permanent, cost-effective and scientifically robust air quality monitoring system for small island environments. The network, which is currently under development, provides a foundation for future applications, including advanced data analysis, potential artificial intelligence-based PM forecasting and regional-scale air quality studies, contributing to improved understanding of air pollution dynamics and supporting evidence-based environmental management for the Maltese Archipelago.

Keywords

air quality monitoring, low-cost sensors, particulate matter, Maltese Archipelago