In recent years, there has been increasing interest in the significance of natural radionuclides, particularly (210)Po, in the marine environment. (210)Po, a naturally occurring alpha emitter, accumulates in marine organisms and reflects differences in their diets. In the literature, there is no data for (210)Po and (210)Pb activity concentrations for fish species on the Turkish coast of Aegean Sea. Therefore, in this study, multiple fish species were collected from six stations seasonally on the Turkish coast of Aegean Sea and were analyzed for their (210)Po and (210)Pb content. The (210)Po and (210)Pb concentrations in the fish samples were found to vary from undetectable levels to 499 ± 44 Bq kg(-1) dry weight (dw) and from 1.0 ± 0.3 Bq kg(-1) to 35 ± 4.0 Bq kg(-1) (dw), respectively. There were no significant differences in the activity concentrations of (210)Po and (210)Pb in fish samples between seasons (ANOVA, P>0.05). The highest dose contribution of (210)Po to humans was calculated to be 10,530 μSv year(-1). 相似文献
Water concentrations of olivine-hosted melt inclusions show no consistent variation across the northern part of the Central American subduction zone in southeastern Guatemala. Magmatic water contents remain moderately high (~2 wt%) throughout the back-arc region. Melt inclusions from some of these back-arc basalts also have notably high CO2 contents (>900 ppm CO2). The B and B/Ce ratios of melt inclusions systematically decline across the arc, the first parameters to exhibit systematic changes across southeastern Guatemala. It appears, therefore, that dehydration-driven, flux-melting persists across the arc, although decompression melting is of approximately equal importance in the back-arc region. Dehydration of the slab/wedge region is regarded as semi-continuous down-dip, to depths of at least 175–200 km. Moderate water contents are maintained by stepwise dehydration reactions, while truly incompatible fluid mobile elements are progressively stripped from the Cocos plate. The notably high CO2 contents of some back-arc basalts may indicate increasing devolatilization of subducted carbonate sediments with slab depth. The moderate H2O contents of back-arc basaltic magmas has likely contributed to their early fractionation of clinopyroxene around the Moho.Editorial responsibility: T.L. Grove 相似文献
Summary The distribution of radioactive elements(Th, U, K) and trace elements(Rb, Sr, Ba, Pb, Zr, Ti, Cu, Cr, Ni, V) of acid granulites from the south-east margin of the Bohemian Massif (SW Moravia) was under study. The investigated rocks are characterized by a great variability ofTh/U ratios andTh andU contents; a linear relationship between theTh andU values was observed. A close relation between theU and biotite contents with a statistically significant linear correlation coefficient of +0.85 was found. In agreement with geological and petrological investigations, the concentrations of radioactive elements correspond to the contents observed in the rocks with metamorphic intensity between the amphibolite and granulite facies. The investigated rocks have extremely lowSr concentrations distinguishing them from other acid granulites of the world.Rb contents are rather variable reaching, however, the highest values among the acid granulites of various granulite areas. 相似文献
International Journal of Earth Sciences - The Žermanice locality represents the best-exposed example of the meta-basaltoid/meta-gabbroic rock type of the teschenite association. It forms a... 相似文献
Water scarcity is a critical issue worldwide, and Chile is no exception. Since 2010, Central Chile has been enduring an ongoing water crisis due to the coupled effects of a severe drought and the overuse of water resources, especially groundwater. Rural communities have been strongly impacted, mainly because wells from which drinking water is supplied show a dramatic drop in water levels, and some have even dried up. The water scarcity scenario requires the integration of actors and disciplines to increase awareness of groundwater; however, how to make this valuable element visible in society is an issue that remains open to debate. This paper describes and reflects on the process of making educational material about groundwater and water scarcity for children to promote public awareness. Based on transdisciplinary and co-designing processes, this work describes the social perceptions of groundwater among children and community leaders, as well as how scientific information and local knowledge of water scarcity could be integrated into a book for the young population. This research finds that educational projects on groundwater resources increase people’s awareness of the role of this hidden resource in the water cycle. Such projects encourage the creation of grounded and contextualised materials that incorporate the knowledge and experience already present in the communities, increasing public awareness of the role of groundwater and associated water scarcity issues, thereby integrating academia and society. This approach could be a tool to lay the foundations for successfully addressing the water crisis in Chile over generations.