Atmospheric lead and bromine in Germany: post-abatement levels, variabilities and trends.
BACKGROUND
Abatement measures since the 1970s have depleted lead and bromine levels in the atmosphere over large parts of Europe. Our knowledge of the atmospheric cycling of these elements while a several decade-long period of intensive mobilization reaches its end is incomplete.


OBJECTIVE
We have characterized the trends in the atmospheric levels of Pb and Br and present-day temporal and spatial variabilities.


METHODS
This was achieved by short-term (weeks) and long-term (years) measurements of particulate Pb and Br at various sites in Germany. Samples of atmospheric particulate matter were collected on filter membranes and analyzed by x-ray fluorescence.


CONCLUSIONS
Average Pb levels at rural and urban inland sites did not exceed concentrations in background aerosols, sampled at a Baltic Sea coastal site, by more than a factor of 3. Due to sea salt, bromide inland particulate Br levels are below those at a coastal site. There, non-sea salt Br, however, is significant as well. Urban Pb and Br levels are not necessarily higher than rural levels. The concentration levels have decreased in such a way that the previously common source, local vehicular traffic emissions, is no longer predominant. Regional rather than local sources have been increasingly determining the concentrations since the 1990s. This is more pronounced for Br than for Pb. We found indications for coal burning and long-range transport as significant Pb sources. For particulate Pb species, a range of ages (elapsed time since Pb emission) has been found. This range shows two maxima corresponding to characteristic times of 72 and 24 h.


CONCLUSIONS
The (mean) atmospheric residence time of particulate Pb is longer than the residence time of Br, in particular in the wintertime. The chemical species contributing to atmospheric Pb should be addressed in future studies.


CONCLUSIONS
Clearly, despite effective abatement measures, atmospheric Pb will continue to be dominated by anthropogenic mobilization. The influence from long-range transport can be expected to decrease with the effectiveness of abatement programmes in neighbouring countries of the region.
Lammel
Gerhard
G
Max Planck Institute for Meteorology, Bundesstrasse 55, D-20146 Hamburg, Germany. lammel@dkrz.de
Röhrl
Andreas
A
Schreiber
Hermann
H
D000336:Aerosols / Q000032:analysis; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D001966:Bromine / Q000032:analysis*; D003031:Coal; D004784:Environmental Monitoring / Q000379:methods; D005858:Germany; D006801:Humans; D017745:Incineration; D007854:Lead / Q000032:analysis*; D012423:Rural Health; D012621:Seasons; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D013997:Time Factors; D014504:Urban Health; D001335:Vehicle Emissions / Q000032:analysis
D000336:Aerosols; D000393:Air Pollutants; D003031:Coal; D001335:Vehicle Emissions; D007854:Lead; D001966:Bromine