SCCPs, MCCPs and LCCPs were found in most of the air samples from all three Nordic capitals. MCCPs were two to six times higher than the SCCPs in all samples. Lower concentrations of SCCPs may be due to the sampling approach, that underestimates the total concentrations of SCCPs in air. MCCPs were seven to 70 times higher than LCCPs in Helsinki while LCCPs were up to three times higher than MCCPs in Reykjavik. The highest concentrations were observed for MCCPs in Helsinki and LCCPs in Reykjavik.
The findings from this study show elevated concentrations of MCCPs and LCCPs at individual sites, but the concentrations at the urban sites were not consistently higher than at the background monitoring sites. The results from this study therefore show no clear relationship to traffic. Instead, sources may be more diffusive and local sources seem to differ.