Application of fast, low-cost spectroscopic sensors to measure nitrogen dioxide in small towns in Ireland

Nitrogen dioxide (NO₂) is a pollutant emitted primarily by vehicles and is strongly associated with large population centres. NO₂ is therefore routinely monitored in cities, but its concentrations in small towns aren’t as well documented, even though some small towns may be traversed by roads with high traffic volumes. This work presents the application of a fast, low-cost cavity-enhanced absorption spectroscopy (CEAS) sensor monitoring of NO₂ levels in three small towns in County Cork, Ireland: Macroom, Killeagh and Millstreet. The respective populations of these towns are approximately 4100, 900, and 1800. The spatial and temporal characteristics of NO₂ in these towns, and the influence of highly polluting vehicles on local air quality are presented. The potential of the novel CEAS system for characterising NO₂ pollution in small population centres is discussed.