Ground based in situ observations of wet_only_sampler at Westerland (DE0001R). 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: benzo_a_pyrene in precip (mass_concentration_of_benzo_a_pyrene_in_precipitation), benzo_bjk_fluoranthenes in precip (mass_concentration_of_benzo_bjk_fluoranthenes_in_precipitation), benzo_ghi_perylene in precip (mass_concentration_of_benzo_ghi_perylene_in_precipitation), chrysene_triphenylene in precip (mass_concentration_of_chrysene_triphenylene_in_precipitation), gamma_HCH in precip (mass_concentration_of_gamma_hexachlorocyclohexane_in_precipitation)