Twenty years of air pollution in eastern Spain: long-term trends and cycles

Abstract

The present study examines daily, weekly and seasonal patterns, as well as long-term trends in nitrogen oxides, ozone and particulate matter ( PM10, PM2.5, and PM1) concentrations in the eastern Spanish Mediterranean coast. Daily cycles were also analysed as a function of the day of the week and season of the year. For this, data from urban, suburban and rural sites of the Regional Air Quality Monitoring Network from 2000 to 2019 were used. In general, daily, weekly and seasonal cycles for NOx, PM2.5 and PM10 were mainly driven by traffic emissions, meteorological conditions and the variability of the mixing layer height. Alternatively, solar radiation intensity was a key factor, although not the only one, controlling O3 concentrations. Some differences in the variability of pollutant concentrations at different time scales depending on the type and specific characteristics of the monitoring station were found. For instance, all urban stations showed an increasing O3 long-term trend, while heterogeneous results were obtained for suburban and rural sites.