Seasonal fluctuations of PM2. 5 concentrations at six Greek islands

PM2.5 concentrations in urban areas vary significantly spatially and seasonally. Measurements can be affected by multiply parameters such as anthropogenic activities, meteorological conditions as well as land use. In the present study one-year PM2.5 measurements from the network of low-cost sensors deployed at six Aegean Sea islands (Lemnos, Lesvos, Chios, Samos, Rhodes, and Syros) were used to study the seasonal changes and the possible impacts from the local sources (e.g., road transport, residential heating) on the air quality. It is the first time that such a long timeseries of PM2.5 concentrations was collected simultaneously at islands with different socioeconomic characteristics (e.g., Syros and Rhodes are among the most popular touristic destinations in Greece) and meteorological conditions (longer warm period in Rhodes in comparison to Lemnos, Lesvos, and Chios). Moreover, citizens’ insight on local air quality and emission sources was collected through the conduction of semi-structured interviews. Results revealed that lower PM2.5 concentrations were recorded during the warm period and the range of minimum – maximum concentrations was smaller. In the cold period peak values ere measured at Lesvos, Samos, and Chios mainly in the evening hours. Comparing the mean seasonal concentrations, it was found that the lowest values were measured at Syros for both warm and cold periods.