As shown in Fig. 2, as an important constituent of biogenic emissions, methyl alcohol was consistently the major OVOC Ezetimibe in the RPD region as well as SDC and GVRD. Acetone was not quantified in the inventory of SDC, but it was consistently the major OVOC species in the PRD and GVRD in Canada. Acetone was mainly emitted from industrial sectors and biogenic sources in the PRD region and GVRD. In addition, 2-butanone, acetaldehyde and IPA were also notable OVOC constituents in the PRD, SDC and GVRD, but the contribution of IPA in SDC was much higher, which might be attributed to the high contribution of printing industry to the local OVOC emissions. Two important OVOC species in the PRD, i.e., ethyl acetate and ethanol, were not estimated in SDC and GVRD. In brief, methyl alcohol and acetone were common high-contributing species in these areas since they were typical biogenic species or raw materials which were widely used in industries. For other species that were less important, some discrepancies were observed given the differences in the quantified species and local source characteristics.