Tracing human mobility in central Europe during the Upper Paleolithic using sub-seasonally resolved Sr isotope records in ornaments.

Mobility of people and goods during the Upper Paleolithic has proven difficult to reconstruct given the relative rareness of remains. Nevertheless, archaeological contexts like the Late Pleistocene horizon of Borsuka Cave (Southern Poland) represent a unique opportunity to explore patterns of objects' transportation across Central Europe. We investigated the origin of four ornaments made of European elk (Alces alces L.) incisors recovered at Borsuka Cave - the oldest known burial site in Poland, possibly a child grave. Laser-ablation plasma source mass spectrometric analyses of trace elements and Sr isotopic compositions revealed that one elk was roaming within a geologically uniform area while the others changed their pastures during their lifetimes. The non-local origin of the elk teeth is inferred from their exotic Sr isotopic compositions and the lack of evidence for the presence of elk in this territory during the Pleistocene. Instead, the elks' Sr isotopic composition show good agreement with sites near the Austria-Slovakia border region and northern Hungary, ~250 km away from the study site. We argue that the artefacts were most likely brought to Borsuka Cave by humans or by a network of exchange, so far never reported in the time range 32.5-28.8 ka cal BP for Southern Poland.

Sources and variation of isotopic ratio of airborne radionuclides in Western Arctic lichens and mosses.

This research concerned radioactivity of lichens and mosses from coastal zones of the Canadian Arctic and Alaska. Over 50 samples were collected from 7 positions during two scientific expeditions in 2012 and 2013. The tundra contamination caused by anthropogenic radionuclides was relatively low, reaching mean values with SD's of: 17.4 ±â€¯3.5 Bq/kg for 90Sr, 14.0 ±â€¯2.9 Bq/kg for 134Cs, 38.4 ±â€¯7.5 Bq/kg for 137Cs, 0.86 ±â€¯0.24 Bq/kg for 239+240Pu, 0.065 ±â€¯0.017 Bq/kg for 238Pu and 0.50 ±â€¯0.13 Bq/kg for 241Am. The increase of activity concentration with increasing latitudes was noticed mostly in regard to 90Sr, Pu isotopes and 241Am. The analysis of isotopic ratios exhibited dominant contribution of the global fallout (+SNAP 9A satellite re-entry fallout) for the presence of plutonium isotopes and 241Am. The Fukushima fallout signature was identified in a few lichens from Alaska. However, the influence of additional unknown factor on the occurrence of 90Sr and 137Cs has been detected in western part of Canadian Arctic. Natural radioisotopes of thorium and uranium were found throughout the entire investigated region and the average values of activity concentration with SD's were as follows: 2.92 ±â€¯0.47 Bq/kg for 230Th, 2.61 ±â€¯0.48 Bq/kg for 232Th, 4.32 ±â€¯0.80 Bq/kg for 234U and 3.97 ±â€¯0.71 Bq/kg for 238U. Examined Western Arctic tundra was not affected with any technically enhanced natural radioactivity.

The radioactive contamination study in south-western Greenland tundra in 2012-2013.

The paper presents results of the radioecological investigation carried out in south-western Greenland shoreline. There were examined over 50 samples of lichens and mosses collected from 7 locations during two scientific expeditions conducted in the summer of 2012-2013. The levels, trends and the most likely origin were determined for following natural and artificial radionuclides: 90Sr, 137Cs, 230, 232Th, 234, 238U, 238, 239+240Pu and 241Am. The radioactive pollution was found as relatively low, reaching the maximum values at: 25.3 ± 2.04 Bq/kg for 90Sr, 293 ± 27 Bq/kg for 137Cs, 4.01 ± 0.13 Bq/kg for 239+240Pu, 0.1381 ± 0.0070 Bq/kg for 238Pu and 1.90 ± 0.21 Bq/kg of 241Am, 9.15 ± 0.48 Bq/kg for 230Th, 25.1 ± 1.2 Bq/kg for 232Th, 7.5 ± 1.5 Bq/kg for 234U and 7.26 ± 0.80 Bq/kg for 238U. Both activity and mass isotopic ratio assays revealed dominant contribution of the global fallout + SNAP 9A on the presence of plutonium isotopes and 241Am in Greenland tundra. However, noticeable deviations of 241Am/239+240Pu and to a lesser extend of 240Pu/239Pu ratios from the GF level have been observed. The origin of 137Cs was evidently connected with the coexistence of global and Chernobyl fallout, while the presence of 90Sr was caused by nuclear weapon tests and affected by leaching process. The seaborne signature of uranium isotopes was manifested in research material as well.

Variations of plutonium isotopic ratios in Antarctic ecosystems.

The aim of the article was to verify the hypothesis concerning the diversification of plutonium sources in the natural environment of Antarctica. Plutonium activity and atom ratios were analyzed in two groups of biological samples: terrestrial and marine. Both isotopic ratios in the terrestrial set were consistent with global radioactive fallout ratios. The average activity ratio in the marine ecosystem was lower than global radioactive fallout. At the same time mass ratio values in this group turned out to be surprisingly varied. Analysis of the results showed statistically significant differences between the marine and terrestrial ecosystems.

Combined, sequential procedure for determination of 137Cs, 40K, 63Ni, 90Sr, 230,232Th, 234,238U, 237Np, 238,239+240Pu and 241Am applied for study on contamination of soils near Zarnowiec Lake (northern Poland).

The paper summarizes results of investigation of the current state of radioactive contamination on site being under consideration for planned nuclear power plant in northern Poland. Thanks to use of sequential procedure it was possible to determine activity concentrations for radioisotopes of nine elements, both natural and artificial. Results show that observed levels of radioactive contamination are rather typical for central Europe and global fallout is dominant factor of presence of artificial radionuclides. The total deposition for artificial radionuclides revealed maxima equal to 1747 ± 121 Bq/m2 for 137Cs, 3854 ± 158 Bq/m2 for 90Sr, 101 ± 23 mBq/m2 for 237Np, 57.7 ± 6.0 Bq/m2 for 241Am, 3.27 ± 0.80 Bq/m2 for 238Pu and 68.5 ± 5.0 Bq/m2 for 239+240Pu.

Plutonium isotopes in the atmosphere of Central Europe: Isotopic composition and time evolution vs. circulation factors.

This paper reports evidence of Pu isotopes in the lower part of the troposphere of Central Europe. The data were obtained based on atmospheric aerosol fraction samples collected from four places in three countries (participating in the informal European network known as the Ring of Five (Ro5)) forming a cell with a surface area of about 200,000km(2). We compared our original data sets from Krakow (Poland, 1990-2007) and Bialystok (Poland, 1991-2007) with the results from two other locations, Prague (Czech Republic; 1997-2004) and Braunschweig (Germany; 1990-2003) to find time evolution of the Pu isotopes. The levels of the activity concentration for (238)Pu and for ((239+240))Pu were estimated to be a few and some tens of nBqm(-3), respectively. However, we also noted some results were much higher (even about 70 times higher) than the average concentration of (238)Pu in the atmosphere. The achieved complex data sets were used to test a new approach to the problem of solving mixing isotopic traces from various sources (here up to three) in one sample. Results of our model, supported by mesoscale atmospheric circulation parameters, suggest that Pu from nuclear weapon accidents or tests and nuclear burnt-up fuel are present in the air.

Plutonium, 90Sr and 241Am in human bones from southern and northeastern parts of Poland.

The paper presents the results of our study on 238Pu, 239Pu, 240Pu, 241Am and 90Sr concentration in human bones carried out on a set of 88 individual samples of central Europe origin. Bone tissue samples were retrieved under surgery while introducing hip joint implants. The conducted surgeries tend to cover either southern or northeastern parts of Poland. While for the southern samples only global fallout was expected to be seen, a mixed global and Chernobyl fallout were to be reflected in the others. Alpha spectrometry was applied to obtain activity concentration for 238Pu, 239+240Pu, 241Am, while liquid scintillation spectrometry for 90Sr and mass spectrometry to receive 240Pu/239Pu mass ratio. Surprisingly enough, and to the contrary to our expectations we could not see any significant differences in either Pu activity or Pu mass ratio between the studied populations. In both populations Chernobyl fraction proved marginal. The results on 90Sr and 241Am confirm similarities between the two examined groups.