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| Titel |
Chemical and isotopical characterisation of atmospheric pollution from urban and rural environments of the Rhine Valley (PCBs, trace elements and Sr-, Nd- and Pb- isotope determinations) |
| VerfasserIn |
F. Guéguen, P. Stille, M. Millet, V. Dietze, R. Giere |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039062
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| Zusammenfassung |
| Atmosheric samples (gas and particulate matter (PM)) have been collected in the urban
environment of the cities of Strasbourg and Kehl and in the rural environment of the
Vosges mountains. For sampling of gas phase pollutants and particles two different
passive sampler devices have been applied (PAS and Sigma-2, respectively). The PAS
has been used for gas phase Polychlorinated Biphenyls (PCBs) sampling and is based on
the passive adsorption of gas phase pollutants onto XAD-2 resin. The Sigma-2 sampler
is based on the sedimentation principle (Stoke’s law), collects particles in the size range
2.5-100 μm and allows the calculation of ambient air concentration. The sampler
is mainly used for routine air quality measurements in German health and
recreation resorts and in this field study the first time for collection of samples for
subsequent trace element and isotope analysis. The collection time for the Sigma-2
and PAS are four and two weeks, respectively. Major and trace elements have
been analyzed by ICP-MS and the Sr, Nd and Pb isotope ratios by a sector
field MC-ICP-MS (Neptune) while PCBs were ASE extracted and analysed by
GC-ECD. The aerosol data are compared with those from tree barks which have
previously been used successfully as biomonitors of atmospheric pollution (Lahd
Geagea et al. 2008)1. The outer 1 mm thick part of the bark has been analyzed
corresponding to about 2 to 8 years of accumulation. Some of the trace elements (Cr,
Ni and Mo) of the aerosol samples are strongly (up to 1000 times) enriched
compared to average “upper continental crust (UCC)”. Normalization to a «
natural » sample with an atmospheric baseline composition allows to identify
industrial contributions: transition metals (Cr, Mn, Fe, Co, Ni, Zn, Mo, Cd), Ba and
Pb appear to be important elements in steel plant and incinerator (chemical
waste) emissions. Similarly enrichment in light rare earth elements (La, Pr,
Nd) is observable. The enrichments increase with decreasing distance from
traffic and the principal industrial activities. UCC normalized trace element
distribution patterns of aerosols and tree bark are very similar. 206Pb/207Pb and
208Pb/207Pb isotope ratios of today’s PM vary within a small range and are
very similar to those of steel plant, waste incinerator and thermal power plant
emissions. Older aerosols (collected 1995, before leaded petrol was phased out), have
significantly lower Pb isotope ratios pointing to the impact of leaded gasoline at that
time. Tree bark monitoring covers a 10-y history of Pb emissions. Combining
Pb isotope ratios with 87Sr/86Sr and 143Nd/144Nd allows for a much better
discrimination between the different anthropogenic emissions and might be suitable for
source apportionments. PCBs concentrations of tree bark or PAS samples
are generally correlated with trace element contents determined on the same
material. PAS/tree bark PCBs ratio allows distinguishing between current or past
contamination.
1Lahd Geagea, M., Stille, P., Gauthier-Lafaye, F., Perrone, Th., Aubert, D. 2008.
Baseline determination of the atmospheric Pb, Sr and Nd isotopic compositions in the
Rhine valley, Vosges mountains (France) and the Central Swiss Alps. Applied
Geochemistry, 23, 1703-1714. |
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