Siting considerations for urban pollution monitors

This paper addresses the problem of comparability between urban pollution data measured at the kerbside. The cost of monitoring and the inadequacy of methodological approaches to analysis have made the existing kerbside data of questionable value. In this paper we briefly review the existing pollution monitoring methodologies and describe those used in this research. The use of a novel, small, affordable, self-contained carbon monoxide (CO) monitor, developed at UCL, has allowed the collection of kerbside data which is highly detailed, both spatially and temporally. This has led in turn to new analysis methods which use location-specific concentration profiles to compare pollution exposure at different sites throughout the full range of readings. We propose that this profile can be used to smooth out the large fluctuations found in time series kerbside pollution data and can also be used to characterise and compare different locations. This method can also be used to compare pollution concentrations for the same location before and after the implementation of different traffic management measures. These detailed data have produced findings of up to a threefold difference in pollutant concentrations (6 min averages of CO measured at head height) between different sides of the same road under cross-wind conditions, with the leeward side of the street experiencing higher levels than the windward.* Finally, we summarise a suggested methodology for data acquisition and analysis in future kerbside atmospheric pollution studies.