Atmospheric deposition of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) in two UK cities

As part of the Toxic Organic Micropollutants Survey (TOMPS) bulk (wet and dry) deposition fluxes of PAHs and PCDD/Fs for 1991/92 are presented for the UK cities of Manchester and Cardiff. The median annual flux for ΣPAH was 5.2 and 4.1 μg/m2/day for Manchester and Cardiff respectively, with an annual ΣPCDD/F flux of 1.4 and 1.0 ng/m2/d. These fluxes were comparable with deposition fluxes reported from other studies and add to the growing international database on deposition measurements. Fluxes were highly variable at both urban sites, with PAH and PCDD/F ranging over an order of magnitude within one season. Seasonality was most apparent for the PCDD/Fs, which showed higher fluxes during the winter months. Simple air to surface transfer velocities (cm/s) were calculated using air concentrations from the same sampling programme.