Ground based in situ observations of high_vol_sampler at Zarra (ES0012R). These measurements are gathered as a part of the following projects EMEP and they are stored in the EBAS database (http://ebas.nilu.no/). Parameters measured are: acenaphthene in pm10 (mass_concentration_of_acenaphthene_in_pm10_in_air), acenaphthylene in pm10 (mass_concentration_of_acenaphthylene_in_pm10_in_air), anthracene in pm10 (mass_concentration_of_anthracene_in_pm10_in_air), benz_a_anthracene in pm10 (mass_concentration_of_benz_a_anthracene_in_pm10_in_air), benzo_a_pyrene in pm10 (mass_concentration_of_benzo_a_pyrene_in_pm10_in_air), benzo_ghi_perylene in pm10 (mass_concentration_of_benzo_ghi_perylene_in_pm10_in_air), benzo_k_fluoranthene in pm10 (mass_concentration_of_benzo_k_fluoranthene_in_pm10_in_air), chrysene in pm10 (mass_concentration_of_chrysene_in_pm10_in_air), dibenzo_ah_anthracene in pm10 (mass_concentration_of_dibenzo_ah_anthracene_in_pm10_in_air), fluoranthene in pm10 (mass_concentration_of_fluoranthene_in_pm10_in_air), fluorene in pm10 (mass_concentration_of_fluorene_in_pm10_in_air), naphthalene in pm10 (mass_concentration_of_naphthalene_in_pm10_in_air), phenanthrene in pm10 (mass_concentration_of_phenanthrene_in_pm10_in_air), pyrene in pm10 (mass_concentration_of_pyrene_in_pm10_in_air)