Ground based in situ observations of high_vol_sampler at Harwell (GB0036R). 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: 5-methylchrysene in aerosol (mass_concentration_of_5_methylchrysene_in_dry_aerosol_particles_in _air), anthanthrene in aerosol (mass_concentration_of_anthanthrene_in_dry_aerosol_particles_in _air), benz_a_anthracene in aerosol (mass_concentration_of_benz_a_anthracene_in_dry_aerosol_particles_in _air), benzo_a_pyrene in aerosol (mass_concentration_of_benzo_a_pyrene_in_dry_aerosol_particles_in _air), benzo_b_fluoranthene in aerosol (mass_concentration_of_benzo_b_fluoranthene_in_dry_aerosol_particles_in _air), benzo_b_naphtho_21_d_thiophene in aerosol (mass_concentration_of_benzo_b_naphtho_21_d_thiophene_in_dry_aerosol_particles_in _air), benzo_c_phenanthrene in aerosol (mass_concentration_of_benzo_c_phenanthrene_in_dry_aerosol_particles_in _air), benzo_e_pyrene in aerosol (mass_concentration_of_benzo_e_pyrene_in_dry_aerosol_particles_in _air), benzo_ghi_perylene in aerosol (mass_concentration_of_benzo_ghi_perylene_in_dry_aerosol_particles_in _air), benzo_j_fluoranthene in aerosol (mass_concentration_of_benzo_j_fluoranthene_in_dry_aerosol_particles_in _air), benzo_k_fluoranthene in aerosol (mass_concentration_of_benzo_k_fluoranthene_in_dry_aerosol_particles_in _air), chrysene in aerosol (mass_concentration_of_chrysene_in_dry_aerosol_particles_in _air), coronene in aerosol (mass_concentration_of_coronene_in_dry_aerosol_particles_in _air), cyclopenta_cd_pyrene in aerosol (mass_concentration_of_cyclopenta_cd_pyrene_in_dry_aerosol_particles_in _air), dibenzo_ac_anthracene in aerosol (mass_concentration_of_dibenzo_ac_anthracene_in_dry_aerosol_particles_in _air), dibenzo_ae_pyrene in aerosol (mass_concentration_of_dibenzo_ae_pyrene_in_dry_aerosol_particles_in _air), dibenzo_ah_anthracene in aerosol (mass_concentration_of_dibenzo_ah_anthracene_in_dry_aerosol_particles_in _air), dibenzo_ah_pyrene in aerosol (mass_concentration_of_dibenzo_ah_pyrene_in_dry_aerosol_particles_in _air), dibenzo_ai_pyrene in aerosol (mass_concentration_of_dibenzo_ai_pyrene_in_dry_aerosol_particles_in _air), dibenzo_al_pyrene in aerosol (mass_concentration_of_dibenzo_al_pyrene_in_dry_aerosol_particles_in _air), inden_123cd_pyrene in aerosol (mass_concentration_of_inden_123cd_pyrene_in_dry_aerosol_particles_in _air), perylene in aerosol (mass_concentration_of_perylene_in_dry_aerosol_particles_in _air)