Selenium Content in Freshwater and Marine Fish from Southern Brazil Coastal Plain: a Comparative Analysis on Environmental and Dietary Aspects

Exploring mercury and selenium dynamics in Amazonian human populations: Insights from urine, blood, and plasma analyses

The Amazonian riverside population is one of the most impacted by mercury, interestingly, with distinct selenium values in blood, generally among the highest worldwide. The interaction between Hg and Se remains to be thoroughly investigated and could provide insights into the fate of these elements and the potential for selenium-mediated detoxification. The current study explores the levels of both elements, determined by inductively coupled plasma mass spectrometry (ICP-MS), in blood, plasma, and urine, of 1089 adult individuals from communities of Tapajós and Amazon River. A large inter-individual variability was found for Hg levels (0.2-139; 0.2-27; 0.1-19 μg Hg.L-1 respectively in blood, plasma, and urine), while Se contents show rather homogenous status in blood (arithmetic mean = 183 ± 78 μg Se.L-1) and plasma (AM = 103 ± 34 μg Se.L-1). Hg content in blood was positively correlated with Hg level in plasma, both increasing with the frequency of fish intake. In contrast, Se levels remained stable in blood regardless of how often fish was consumed. However, a positive correlation was observed between Hg and Se excreted in urine. This work represents the largest human cohort in the region, pioneering the evaluation of the levels of both elements simultaneously in blood, plasma, and urine, laying the foundations for understanding the dynamics of Hg and Se in Amazonian riverside populations.

The importance of selenium in food enrichment processes. A comprehensive review

Selenium is an essential element that determines the proper life functions of human and animal organisms. The content of selenium in food varies depending on the region and soil conditions. Therefore, the main source is a properly selected diet. However, in many countries, there are shortages of this element in the soil and local food. Too low an amount of this element in food can lead to many adverse changes in the body. The consequence of this may also be the occurrence of numerous potentially life-threatening diseases. Therefore, it is very important to properly introduce methods that condition the supplementation of the appropriate chemical form of this element, especially in areas with deficient selenium content. This review aims to summarize the published literature on the characterization of different types of selenium-enriched foods. At the same time, legal regulations and prospects for the future related to the production of food enriched with this element are presented. It should be noted that there are limitations and concerns with the production of such food due to the narrow safety range between the necessary and the toxic dose of this element. Therefore, selenium has been treated with special care for a very long time. For this reason, the presented mechanisms of production processes related to increasing the scale of selenium supplementation should be constantly monitored. Appropriate monitoring and development of the technological process for the production of selenium-enriched food is very important. Such food should ensure consumer safety and repeatability of the obtained product. Understanding the mechanisms and possibilities of selenium accumulation by plants and animals is one of the most important directions in the development of modern bromatology and the science of supplementation. This is particularly important in the case of rational nutrition and supplementing the human diet with an essential element such as selenium. Food technology is facing these challenges today.

Potentially Toxic Elements in Water, Sediments and Fish from the Karstic River (Raša River, Croatia) Located in the Former Coal-Mining Area

The assessment of the environmental quality of a sensitive karst aquatic system under the centuries-long anthropogenic influence of the coal mining industry is important for both improving the quality of water resources and protecting aquatic wildlife and human health. In this study, we investigated the anthropogenic impact on the aquatic environment of the upper and middle course of the Raša River through the analysis of a suite of metal(loid)s in three aquatic compartments (water, sediment, fish) using inductively coupled plasma mass spectrometry (ICP-MS). Concentrations of inorganic constituents in water were low, while the chemical composition of stream sediments mainly reflected the geological background of the area, indicating the origin of metal(loid)s from predominantly natural sources. Although comparison with PEC-Q values indicated that existing sediment quality conditions could pose a threat to benthic organisms with regard to Cr and Ni, the constant vertical profiles of these elements suggested their natural origin from the weathering of flysch. Element levels in the muscle of targeted fish species were in accordance with the values typical for low-contaminated freshwater systems, while levels of Cd, Pb and Hg were mostly below the European regulatory limits for toxic elements in foods, indicating that the low concentrations of most contaminants in muscles of fish from the Raša River do not present a risk to humans or other consumers. The obtained data indicated a generally low contamination status of the western part of the Raša River basin with regard to the analyzed inorganic elements.