The assessment of the presence and main constituents of particulate matter ten microns (PM 10) in Irish, rural and urban air

Abstract

This work summarizes the results of a series of comprehensive studies on particulate matter (PM 10) carried out in County Cork, Ireland from 2005 to 2006. Monitoring sites were selected in accordance with different climatic and geographic conditions as well as anthropogenic influences, varying from rural background to industrial sites. Measurements were carried out with gravimetric high-volume samplers coupled with validated elemental analyses using Inductively Coupled Plasma-Optical Emission Spectroscopy, ion chromatography and flow injection analysis. Mean daily values, chemical compositions and source apportionment analyses were obtained and discussed as a function of the diverse monitoring sites and varying climatic episodes. High PM 10 episodes are recorded during continental air mass impacts on Ireland, with a 50% increase in particulate concentration from the average values recorded in 2005. Chemical specification data, carried out by Principle Component Analysis (PCA) shows an increase in the crustal mineral load for most of the study sites. Furthermore, a high marine aerosol load is evident in coastal and urban study sites. The daily mean PM 10 levels of 34 μg m −3 for an industrial region and 20 μg m −3 for coastal – rural site, with the urban site recording 14 μg m −3 are indicative of the Irish atmospheric air quality (allowing for local variations and weather). The natural background contribution in this region is estimated to be 3 μg m −3. The contribution from natural re-suspension and marine aerosol measured in this study can account for up to 56% of the 2010 EU annual limit value (20 μg m −3 PM 10) under directive European Community (1999/30/EC). This contribution will account for up to 28% of the revised annual limit (40 μg m −3 PM 10) under directive (2008/50/EC). The study demonstrates, that it could be challenging for a country such as Ireland whose national air pollution levels are low, as well as for other EU member states to meet the air quality limit in directive European Community (1999/30/EC).