Effect of long-range transport on local PM10 concentrations in the UK

This study describes the effects of long-range transport of secondary airborne particles on local PM10 levels in Edinburgh (UK) during the period 1 January to 31 March 1996. Air mass back trajectories for each day were grouped into six atmospheric transport patterns to examine their influences on local PM10 concentrations. Significant differences in receptor PM10 concentrations were observed between the trajectory patterns (p = 0.1%). Air masses from Eastern Europe resulted in higher daily PM10 averages than any of the other patterns (p = 1.0%). Median PM10 concentrations in Edinburgh increased by 10-15 mu g m(-3) when air mass trajectories were from these regions. This effect should be considered by local authorities to acknowledge that not all PM10 sources are possible to control in local air quality management areas. Further evidence of the influence of long-range transport was found by detailed examination of the concurrent development of a pollution episode in Edinburgh, London and Belfast. Differences in the temporal development of the episode in the three cities were attributed to trajectory variations in the proximity of frontal weather systems.