<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Study of soils in St. John’s, Canada showed elevated Pb levels representing a potential ex-posure risk for young children. Old trees growing in the city present a potential annually-resolved record of Pb levels over past centuries that provides important temporal and spatial dimensions to Pb exposure risk assessment. This paper reports the results of our analytical tests to develop a fast, relia-ble and cost-efficient method using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for measuring Pb concentration in annual tree rings from available tree species. Our tests focused on approaches to sample preparation as they affect the laser ablation process, the relative merits of the ablation sampling method, and the response of our available tree species, which have contrasting wood structures, to laser ablation. The range of annual Pb concentrations (ppm) measured for each of the study species were as follows: spruce (0.18–6.42); elm (0.12–7.91); and horse chestnut (0.40–14.09). Our results demonstrate that the cutting procedure for preparing tree cores produced the most consistent Pb concentrations of the three methods, although they each displayed problematic anomalies. The selection of the best laser ablation technique appears to be highly dependent on study species and goals. In general, spot analysis permits detailed and targeted studies of tree-ring struc-tures, but requires careful sampling attention for species with complex wood anatomy. The line scan method is ideal for reconstructing annually resolved element concentrations from trees and to some degree mitigates the complicating issue of intra-ring variability. Horse chestnut was determined to be the best of the available tree species because it exhibited a good response to laser ablation and pro-duced the lowest intra-ring variations in Pb concentration.</p></abstract>

Study of soils in St. John’s, Canada showed elevated Pb levels representing a potential ex-posure risk for young children. Old trees growing in the city present a potential annually-resolved record of Pb levels over past centuries that provides important temporal and spatial dimensions to Pb exposure risk assessment. This paper reports the results of our analytical tests to develop a fast, relia-ble and cost-efficient method using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for measuring Pb concentration in annual tree rings from available tree species. Our tests focused on approaches to sample preparation as they affect the laser ablation process, the relative merits of the ablation sampling method, and the response of our available tree species, which have contrasting wood structures, to laser ablation. The range of annual Pb concentrations (ppm) measured for each of the study species were as follows: spruce (0.18–6.42); elm (0.12–7.91); and horse chestnut (0.40–14.09). Our results demonstrate that the cutting procedure for preparing tree cores produced the most consistent Pb concentrations of the three methods, although they each displayed problematic anomalies. The selection of the best laser ablation technique appears to be highly dependent on study species and goals. In general, spot analysis permits detailed and targeted studies of tree-ring struc-tures, but requires careful sampling attention for species with complex wood anatomy. The line scan method is ideal for reconstructing annually resolved element concentrations from trees and to some degree mitigates the complicating issue of intra-ring variability. Horse chestnut was determined to be the best of the available tree species because it exhibited a good response to laser ablation and pro-duced the lowest intra-ring variations in Pb concentration.

Some considerations in the reconstruction of lead levels using laser ablation: lessons from the design stage of dendrochemistry study, St.John's, Canada

Department of Geography, Memorial University of Newfoundland, 232 Elizabeth Ave, St John's, NL A1B 3X9, Canada

Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland

Department of Soil Science, University of Saskatchewan, 51Campus Drive, Saskatoon, SK S7N 5A8, Canada

Geochronometria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Study of soils in St. John’s, Canada showed elevated Pb levels representing a potential ex-posure risk for young children. Old trees growing in the city...

Some considerations in the reconstruction of lead levels using laser ablation: lessons from the design stage of dendrochemistry study, St.John's, Canada

Publié en ligne: 31 déc. 2015

Pages: -

Reçu: 08 juin 2015

Accepté: 06 nov. 2015

DOI: https://doi.org/10.1515/geochr-2015-0024

Mots clés
tree rings, dendrochemistry, laser ablation, ICP-MS, urban lead contamination

© 2015 M. Danek et al.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Some considerations in the reconstruction of lead levels using laser ablation: lessons from the design stage of dendrochemistry study, St.John's, Canada

Publié en ligne: 31 déc. 2015

Pages: -

Reçu: 08 juin 2015

Accepté: 06 nov. 2015

DOI: https://doi.org/10.1515/geochr-2015-0024

Mots cléstree rings, dendrochemistry, laser ablation, ICP-MS, urban lead contamination

© 2015 M. Danek et al.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
tree rings, dendrochemistry, laser ablation, ICP-MS, urban lead contamination