There were only marginal differences in correlations between different noise and air pollution metrics. Correlations were strongest between noise metric and the traffic component of particulates (PM2.5traffic and PM10traffic) because modelled noise in our analysis comes entirely from road traffic sources. We observed weak negative correlations, as expected, between ozone and noise metrics (r = − 0.34 to − 0.38). A reason for these weaker correlations might be that noise is geographically smoother in background areas where we did not have traffic information for minor roads, and consequently no variability in locations where ozone variability is expected to be high. This is confirmed by the correlations between ozone and noise metrics stratified by exposure bands where negative correlations are strongest in the lowest ozone exposure tertile (i.e. close to main roads), and weakest in the highest exposure tertile (i.e. in background locations).