Atmospheric Lead and Bromine Levels in Central Europe

Abatement measures (fuel composition) in recent years have depleted Pb and Br values in the environment in central Europe. We studied atmospheric lead, Pb, and bromine, Br, over a two-year period at an urban site (Leipzig, weekly PM₁₀ samples), and at several rural and urban sites in short-term campaigns (mostly daily TSP samples) in central Europe, 1998-2000. The samples were collected on quartz fibre filters and analyzed using x-ray fluorescence analysis (total element contents). In the long-term study at the urban site, the levels were found to be 19.2 ng m^-3 (0.66 mg g^-1 PM₁₀) and 3.2 ng m^-3 (0.11 mg/g PM₁₀) for Pb and Br, respectively, as the annual mean. Winter concentrations exceeded summer concentrations by a factor of 3, similar to other anthropogenically highly enriched elements (crustal enrichment factors for Pb and Br were 550 and 490, respectively). At rural sites (total sampling time 7 weeks) the levels were 13.4 ng m^-3 (0.62 mg g^-1 TSP) and 5.1 ng m^-3 (0.24 mg g^-1 TSP) for Pb and Br, respectively. The two elements are correlated, however, less pronounced than previously. By average, it was Pb/Br = 6.2. This value is higher than observed in previous years in Germany which raises the question whether sources other than vehicular traffic are significant today. Time dependent correlation coefficients between particulate phase mass fractions and source loadings which were based on air mass back trajectory analyses suggest the existence of two Pb species, which are undergoing a selection process during aging and, hence, differ by their atmospheric residence time.