Trends in ambient ozone, nitrogen dioxide, and particulate matter concentrations over the Maltese Islands and the corresponding health impacts.

This study presents an overview of the air pollution levels in the Maltese Islands including trends in particulate matter (PM), ozone (O3) and nitrogen dioxide (NO2) at four monitoring stations in Malta and one in Gozo between 2008 and 2017. In addition, the health impacts associated with long-term exposure to annual mean PM2.5 and NO2 are estimated at each site. Irrespective of the site, PM10 and PM2.5 concentrations show statistically significant decreasing trends while statistically significant increasing trends are noted for the coarse fraction, PM2.5-10 and O3. Trends for the different pollutants vary for each site and differ from the overall trend both in magnitude and sign especially for NO2 concentrations. The attributable fraction (AF) associated with long-term exposure to PM2.5 and NO2 ranges from 0.67% (CI: 0.27%,1.07%) in Għarb to 11.79% (CI: 7.77,15.45) in Msida (2011). The corresponding attributable mortality is estimated to reach a maximum of 119 (CI: 78,156) attributable deaths associated with long-term exposure to PM2.5 in Msida in 2011. This paper thus highlights the importance of continuous air quality monitoring in distinctively different conurbations especially for pollutants showing increasing trends and is the first to outline the potential long-term health effects of air pollutant concentrations in the Maltese Islands.