The use of real-time monitoring data to evaluate major sources of airborne particulate matter

Real-time chemical measurements have been made as part of a field study of air quality in the city and harbour of Cork, Ireland. The data relate to the year 2008, with particular attention paid to the period between May and August. Eight air quality parameters were measured: NO, O3, NO2, SO2, EC, OC, particulate SO42− and PM2.5. The data have been used in a novel way involving wind and temporal averaging, along with Principal Component Analysis (PCA) and Positive Matrix Factorisation (PMF) methodologies to extrapolate major source contributions for PM2.5. It is demonstrated that continuous monitoring of standard air quality parameters, such as NO, NO2, SO2, along with EC, OC and particulate SO42−, can be used to provide relevant, cost-effective initial estimates of source contributions to ambient PM2.5 levels. It is also shown that the benefit of including OC and particulate SO42− in the monitoring protocol is considerable. Three major source groups of ambient PM2.5 mass in Cork were identified and quantified using this combined monitoring and modelling approach; road transport (19%), domestic solid fuel burning (14%) and oil-fired domestic and industrial boilers, including power generation plants (31%).