Ground based in situ observations of pm10_mass at Westerland (DE0001R) using filter_1pack. These measurements are gathered as a part of the following projects EMEP, CAMPAIGN and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: pm10_mass in pm10 (mass_concentration_of_pm10_ambient_aerosol_particles_in_air)