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Supplementary material for Potential source areas for atmospheric lead reaching Ny-Ålesund from 2010 to 2018. This repository contains source code and additional supplementary materials from our manuscript, "Supplementary material for Potential source areas for atmospheric lead reaching Ny-Ålesund from 2010 to 2018". Please, cite the main article as: Bazzano, A.; Bertinetti, S.; Ardini, F.; Cappelletti, D.; Grotti, M. Potential Source Areas for Atmospheric Lead Reaching Ny-Ålesund from 2010 to 2018. Atmosphere 2021, 12 (3): 388, doi:10.3390/atmos12030388.

In the context of environmental studies, isotope ratio measurements can help to discriminate between natural and anthropogenic inputs, as well as to identify their source regions and transport pathways. However, environmental samples can be characterised by a low amount of the target elements, thus hindering the measurement of precise and accurate isotope ratios. During this doctoral study, research activity was carried out taking into account both analytical and environmental aspects related to the determination of isotope ratios in environmental matrices. On the analytical side, much effort was focused on obtaining precise and accurate isotope ratios at low amount of the target element, using single-collector and multi-collector inductively coupled plasma mass spectrometry (ICP-MS). In particular, performances obtained measuring 208Pb/207Pb and 206Pb/ 207Pb ratios by single-collector ICP-MS at low sample consumption rates were investigated evaluating two micro-sample introduction systems: the PFA micro-nebuliser, working at 150 μL/min, and the torch integrated sample introduction system (TISIS), working at 20 μL/min. Under optimal conditions and using ammonia as damping gas, repeatability was 0.12 ± 0.03 and 0.17 ± 0.04 % RSD at 10 ng/mL of Pb, whereas the sample consumption was < 1.5 and 0.2 mL. TISIS was also coupled with multi-collector ICP-MS achieving a repeatability of 0.016 % consuming only 0.2 mL of sample solution. The coupling of the instrumental method with a pre-concentration step provided accurate ratios at Pb concentration levels down to 5 pg/g. Finally, the use of multi-collector ICP-MS with a membrane nebuliser desolvating system was also investigated for the measurement of precise and accurate 87Sr/86Sr ratios, obtaining an intermediate precision of 0.019 % at 0.4 ng/mL Sr concentration. The developed methods were largely applied to various environmental studies in the framework of PNRA (Italian National Program for Antarctic Research) and RIS (Research in Svalbard) projects. Indeed, Pb isotope ratios were precisely and accurately measured in atmospheric particulate, surface snow, marine suspended particulate matter and sediment samples, collected from both the Arctic and Antarctica. Data were discussed in a multidisciplinary context and provided very useful information on sources and transport pathways of trace elements. In particular, results for atmospheric particulate matter collected at Ny-Ålesund (Svalbard islands), showed a recurring seasonal transition with higher load of atmospheric Pb related to mining activities in Russia during spring, and inputs of anthropogenic Pb coming from eastern North America during summer. Similar measurements were also applied to suspend particulate matter collected from the marine environment of the Kongsfjorden (close to Ny-Ålesund) and distinguished between anthropogenic Pb associated to intruding Atlantic water, and crustal Pb associated to glacial run-off. In the context of the Antarctic research, the chemical and isotopic characterisation of size-segregated atmospheric particulate collected at Terra Nova Bay (Northern Victoria Land) revealed that both the crustal and anthropogenic elements were related to the air masses carried by the katabatic wind from the inland, whereas the marine input appeared to be higher in January when the sea-ice extent was reduced. Furthermore, the Pb isotope ratios pointed out that the anthropogenic input was likely related to the polluted aerosols from South America and Australia, representing the predominant fraction (50–70 %) of the Pb measured in the samples. Finally, the precise measurement of Pb isotope ratios in surface snow from the Antarctic plateau enabled the identification of seasonal and inter-annual variations in the main sources of atmospheric Pb reaching Antarctica.