Impact of distance from the glacier on the content of 137Cs and 90Sr in the lichen Cetrariella delisei

Assessing the present levels of 137Cs in the remote ecosystem of Bjornoya (South Svalbard)

The remoteness and small size of Bjornoya (S Svalbard) make the island one of the most unreachable places in the Arctic. Limited accessibility contributes to still-existing knowledge gap on isotope accumulation in compartments of its ecosystem. Therefore, in this study we aimed to investigate the current concentration of 137Cs in the terrestrial samples of vascular plants, cryptogams, and soil collected on Bjornoya in 2021. The measured average activity of 137Cs in bryophytes was 56.5 Bq kg-1, lichens 27.6 Bq kg-1, vascular plants 7.26 Bq kg-1, and soil 9.63 Bq kg-1. In the case of bryophytes, 137Cs activity was negatively correlated with δ15N. Our results suggest that bird guano was the main source of nitrogen and 137Cs for vascular plants. For bryophytes, significantly lower values of δ15N than in vascular plants suggests that this group is more sensitive to atmospheric N intake, with fallout being the main source of 137Cs.

Distribution of 90Sr and 137Cs in biotic and abiotic elements of the coastal zone of the King George Island (South Shetland Archipelago, Antarctic Peninsula)

For many years Antarctic ecosystems have been considered pristine, however recent studies, including our results, contradict this assumption. Our comprehensive study on the activity of anthropogenic radioisotopes (¹³⁷Cs and ⁹⁰Sr) in the most common species of green algae, bryophytes, lichens, and vascular plants, as well as soil and guano samples collected over a large area on King George Island (South Shetland Archipelago) in the austral summer 2018/2019 clearly indicate the importance of large-scale transport in shaping the level of pollution in areas very distant from potential sources of contamination. Additionally, radioisotope pollution can be measured even after a very long period (>60 years) since their occurrence. The mean activity of ¹³⁷Cs measured in lichens, bryophytes, vascular plants, green algae, soil, and guano was, respectively: 3.72 Bq kg^-1_dw, 3.70 Bq kg^-1_dw, 2.62 Bq kg^-1_dw, 2.26 Bq kg^-1_dw, 4.07 Bq kg^-1_dw and 2.08 Bq kg^-1_dw. For ⁹⁰Sr mean activity in lichens, bryophytes, vascular plants, green algae, and soil was, respectively: 1.99 Bq kg^-1_dw, 3.05 Bq kg^-1_dw, 2.42 Bq kg^-1_dw, 1.08 Bq kg^-1_dw, and 6.43 Bq kg^-1_dw. Increased activities of ⁹⁰Sr and ¹³⁷Cs were observed in species collected in the area influenced by glacier melt and penguin guano.

Mercury concentration and speciation in benthic organisms from Isfjorden, Svalbard

Polar regions are an important part of the global mercury cycle and interesting study sites due to different possible mercury sources. The full understanding of mercury transformations in the Arctic is difficult because this region is the systems in transition -where the effects of the global climate change are the most prominent. Benthic organisms can be valuable bioindicators of heavy metal contamination. In July 2018, selected benthic organisms: macroalgae, brittle stars, sea urchins, gastropods, and starfish were collected in Isfjorden, Spitsbergen. Two of the sampling stations were located inside the fjord system and one at the entrance to the fjord. The results showed that the starfish were the most contaminated with mercury. Total mercury concentrations in these organisms were at least 10 times higher than in other organisms. However, they effectively deal with mercury by transporting it to hard tissue. The dominant form of mercury was the labile form.

Current radioactive fallout contamination along a trans-European gradient assessed using terricolous lichens

Lichens are considered to be good indicators of contamination of the terrestrial environment. In this study, we investigated the level of ¹³⁷Cs and ⁴ K accumulated by Cladonia arbuscula and Stereocaulon alpinum along a longitudinal gradient from northern Norway, across Sweden to southern Poland. Additionally, we compared isotope contents between the selected lichen species, and investigated the correlation of the ¹³⁷Cs content accumulated by C. arbuscula with ¹³⁷Cs fallout after the Chernobyl disaster. The activity of ¹³⁷Cs varied from 3.58 Bq kg^-1 to 559 Bq kg^-1 for S. alpinum, and from 1.18 Bq kg^-1 to 130 Bq kg^-1 for C. arbuscula. The activity of ⁴ K ranged from 114 Bq kg^-1 to 341 Bq kg^-1 for S. alpinum and from 27.2 Bq kg^-1 to 314 Bq kg^-1 for C. arbuscula. The ¹³⁷Cs content did not differ between C. arbuscula and S. alpinum; however, the difference between species was significant for ⁴ K accumulation. The activity of ¹³⁷Cs in C. arbuscula was significantly correlated with deposition from 1986. Based on our findings we created a spatial map of ¹³⁷Cs activity in lichens measured 30 years after the event that was the primary source of this isotope. We showed that C. arbuscula can be used to assess contamination and create interpolation maps of radionuclide deposition, even if the primary deposition took place many years ago.

137Cs and 40K activity concentrations in edible wild mushrooms from China regions during the 2014–2016 period

Introduction. Contamination by radiocaesium of edible wild mushrooms after major nuclear accidents is a long-lasting process in some regions of the world. Following greater awareness of radioactive pollution in Asia, particularly after the Fukushima accident, this study investigated the radioactivity of 137Cs and 40K contamination in edible wild mushrooms in China. Study objects and methods. The objects of the research were edible wild mushrooms collected during 2014 to 2016, from the Inner Mongolian and Yunnan regions of China. To obtain an insight into any environmental impacts to distant regions of mainland Asia, the mushrooms were analyzed for 137Cs activity. In parallel, the natural activity of 40K was also determined and used to estimate the content of total K. The topsoil underneath the mushrooms was also investigated from a few sites in Bayanhushu in Inner Mongolia in 2015. Results and discussion. The results showed that in 4 to 6 mushrooming seasons after the accident, mushrooms from both regions were only slightly contaminated with 137Cs, which implied negligible consequences. The activity concentrations of 137Cs in dried caps and whole mushrooms in 63 of 70 lots from 26 locations were well below 20 Bq kg–1 dry weight. Two species (Lactarius hygrophoroides L. and Lactarius volemus L.), from Jiulongchi in Yuxi prefecture showed higher 137Cs activities, from 130 ± 5 to 210 ± 13 Bq kg–1 dw in the caps. 40K activities of mushrooms were around two- to three-fold higher. A composite sample of topsoil (0–10 cm layer) from the Bayanhushu site (altitude 920 m a.s.l.) in Inner Mongolia showed 137Cs activity concentration at a low level of 6.8 ± 0.7 Bq kg–1 dw, but it was relatively rich in potassium (40K of 595 ± 41 Bq kg–1 and total K of 17000 ± 1000 mg kg–1 dw). Conclusion. Wild mushrooms from the Yunnan and Inner Mongolia lands only slightly affected with radioactivity from artificial 137Cs. Lack of 134Cs showed negligible impact from Fukushima fallout. Ionizing radiation dose from 137Cs in potential meals was a fraction of 40K radioactivity. The associated dietary exposure to ionizing irradiation from 137Cs and 40K contained in mushrooms from the regions studied was considered negligible and low, respectively. Mushroom species examined in this study are a potentially good source of dietary potassium.

Effect of drying, blanching, pickling and maceration on the fate of 40K, total K and 137Cs in bolete mushrooms and dietary intake

The effects of blanching, blanching and pickling and maceration on the leaching of ¹³⁷Cs and ⁴⁰K from the flesh of three edible bolete mushroom species-Boletus edulis, Leccinum scabrum and Leccinum versipelle-were investigated. Significant (p < 0.05) decreases in activity were observed but varied depending on the treatment. Relative to fresh mushrooms, blanching decreased the activity concentration of ¹³⁷Cs by 15 ± 13%, and of ⁴⁰K, by 16 ± 7%, but blanching and pickling (vinegar) reduced activity more effectively, by 55 ± 8% and 40 ± 20% respectively. The corresponding losses of ¹³⁷Cs and ⁴⁰K through maceration of dried, powdered mushrooms were 38 ± 11% and 35 ± 14% ww, respectively. These results indicate that traditional domestic processing methods may not be as efficient at excluding ¹³⁷Cs radioactivity as shown in some other studies. The activity concentration of ¹³⁷Cs in a typically sized (100 g) portion of a processed mushroom (sourced from nearshore regions of the southern Baltic Sea coast near Gdańsk in 2015) meal was projected to be low, i.e. in the range of 0.51 to 12 Bq kg^-1 ww. The corresponding effective dose of ¹³⁷Cs from blanched, blanched and pickled and macerated mushrooms per capita was also assessed to be low, from 0.001 to 0.010 μSv. Nutritionally, the median concentration of potassium (330 mg) in 100 g portions of blanched or pickled mushrooms would account for around 7% of the adequate adult daily intake.

Functional Traits in Lichen Ecology: A Review of Challenge and Opportunity

Community ecology has experienced a major transition, from a focus on patterns in taxonomic composition, to revealing the processes underlying community assembly through the analysis of species functional traits. The power of the functional trait approach is its generality, predictive capacity such as with respect to environmental change, and, through linkage of response and effect traits, the synthesis of community assembly with ecosystem function and services. Lichens are a potentially rich source of information about how traits govern community structure and function, thereby creating opportunity to better integrate lichens into 'mainstream' ecological studies, while lichen ecology and conservation can also benefit from using the trait approach as an investigative tool. This paper brings together a range of author perspectives to review the use of traits in lichenology, particularly with respect to European ecosystems from the Mediterranean to the Arctic-Alpine. It emphasizes the types of traits that lichenologists have used in their studies, both response and effect, the bundling of traits towards the evolution of life-history strategies, and the critical importance of scale (both spatial and temporal) in functional trait ecology.