Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements
Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements Citation for published version: Gillespie, J, Masey, N, Heal, MR, Hamilton, S & Beverland, IJ 2017, 'Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements' Atmospheric Environment, vol 150, pp. 295-302. a b s t r a c t Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires
... ntial time and monitoring equipment. The objective of this study was to establish if shortduration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO 2 ) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40e80%, and 7e64% respectively, of spatial variation in the intervening 1-week NO 2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO 2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1week NO 2 concentrations over the same period. The relatively high explained variation observed between BC and NO 2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.