Multi-season, multi-year concentrations and correlations amongst the BTEX group of VOCs in an urbanized industrial city

► High density, multi-year, multi-season network to monitor VOC concentrations. ► Determination of annual variability of concentrations and correlations. ► Seasonal trends and identification of proxy seasons for annual exposure. ► Investigation of key ratios indicative of source origin and photochemical age. ► Spatial variability and misclassification associated with central monitoring.