C2-C6 Background Hydrocarbon Concentrations Monitored at a Roof Top and Green Park Site, in Dublin City Centre

Abstract

A 5 week monitoring campaign was carried out in Dublin City centre, to establish which site gave a more accurate background city centre estimation: a roof-top or green field site. This background represented a conservative estimate of HC exposure in Dublin City centre, useful for quantifying health effects related to this form of pollution and also for establishing a local background relative to the four surrounding main roads when the wind direction is travelling towards each road with the background receptor upwind. Over the entire monitoring campaign, the lowest concentrations and relative standard deviations were observed at the green field site, regardless of time of day or meteorological effects.

Local and regional sources of C2–C8 hydrocarbon concentrations at a sub-urban motorway site (M4) in Ireland

“…For the local (M4) emissions, an average ratio of 2.62 is obtained, primarily a function of the fleet make up (HGV's relative to smaller vehicles), as the model will predict that both compounds disperse to a similar extent in time and space (over the small area from M4 to receptor). However, the average regional E:A ratio was seen to be very similar to estimated "background" ratios, observed in the greater Dublin area (O'Donoghue and Broderick 2007b). An average value of 0.99 was obtained, verifying the ability to use this ratio as a marker for regional or "background" contributions.…”