The performances of different particle lung-deposited surface area (LDSA^al) measurement methods (Partector, ELPI+, SMPS/DMPS) were compared in ambient conditions. As LDSA^al is a health-relevant metric and rather easy to utilise in air quality monitoring, it is crucial to know how the different methods agree, as there are clear differences in their operation. In all, a comparison of different methods can be complicated; still, the methods agree rather well in terms of local pollution (< 400 nm).