Multiannual monitoring (1974-2019) of rare earth elements in wild growing edible mushroom species in Polish forests.

There is a growing demand for rare earth elements (REEs) due to their use in modern technologies, and this may result in their emission to the environment. This is the first long-term study to monitor the content of REEs in four edible mushroom species. Over 21,900 samples of fruit bodies (sporocarps) of Boletus edulis, Imleria badia, Leccinum scabrum and Macrolepiota procera and their underlying soils, collected between 1974 and 2019 from 42 forest sites in Poland were examined in an attempt to understand the time evolution of the presence of REEs in the environment. In general, I. badia and B. edulis displayed a greater total content of REEs on mg per kg basis than L. scabrum and M. procera. A gradual increase in REEs in the studied mushrooms as well as associated forest soil samples was observed over the monitored period. Both levels were also highly correlated. Regardless of the considered period, human consumption of these mushrooms would not contribute significantly to dietary exposure to REEs. Wild growing mushroom species studied over a long time period may be a good bioindicator of REE migration to the environment.

Phytoextraction of arsenic forms in selected tree species growing in As-polluted mining sludge.

The aim of this study was to determine the phytoextraction of inorganic (As(III), As(V)) and organic arsenic (Asorg) forms in six tree species: Acer platanoides, Acer pseudoplatanus, Betula pendula, Quercus robur, Tilia cordata and Ulmus laevis. Plants were grown in a pot experiment using As-polluted mining sludge for 90 days. Arsenic (Astotal) was accumulated mainly in the roots of all six tree species, which were generally thinner, shorter and/or black after the experiment. The highest concentration of As(III) and As(V) was determined in the roots of A. pseudoplatanus and A. platanoides (174 and 420 mg kg-1, respectively). High concentrations of As(III) were also recorded in the shoots of B. pendula (11.9 mg kg-1) and As(V) in the aerial parts of U. laevis and A. pseudoplatanus (77.4 and 70.1 mg kg-1). With some exceptions, the dominant form in the tree organs was Asorg, present in mining sludge in low concentration. This form has a decisive influence on As phytoextraction by young tree seedlings even though its BCF value was the only one lower than 1. The obtained results highlight the important role of speciation studies in assessing the response of plants growing in heavily polluted mining sludge.

Salix viminalis L. - A highly effective plant in phytoextraction of elements.

The aim of the study was to compare specimens of Salix viminalis L. able to grow in polluted mining sludge (A1) with specimens of the same willow clone growing in two unpolluted areas (A2 and A3). Plants from the polluted area were characterized by the highest accumulation of the majority of elements in their organs with a clear limitation of their uptake to roots and effective translocation to aboveground organs. Willows from the unpolluted areas were characterized by significantly higher biomass than the treated plants, as shown in the content of cellulose/holocellulose. The different chemical characteristics of the substrates influenced tree physiology, including the organic acids and phenolic compounds profile and/or content. The total content of organic acids in lateral roots was higher for S. viminalis L. grown in unpolluted areas, while for leaves the opposite situation was observed. However, their creation was significantly correlated with the content of the majority of elements in the organs of S. viminalis L. Enhanced synthesis of phenolic compounds in roots (besides quercetin) and in leaves (besides myricetin and quercetin) was confirmed in the polluted area, and correlated with metal content in plant organs. Resilient plants characterized not only by their survivability but also by their effective phytoextraction of toxic metals, have great potential for widespread practical application on highly polluted mining sludge and for reducing the associated threat to human health. The obtained results suggest that further investigation of these plants is necessary to determine the mechanism(s) responsible for their high survivability.

Sugar and inorganic anions content in mineral and spring water-based beverages.

BACKGROUND: Carbonated and non-carbonated beverages manufactured based on mineral and spring waters have been present at the Polish market shortly, and their production and sales are regularly growing. The products have become commonly known as flavoured waters. OBJECTIVE: The aim of the work was to identify and assess the content of carbohydrates used for sweetening mineral and spring water-based beverages and to estimate a concentration of inorganic anions. MATERIAL AND METHODS: The study was undertaken for 15 mineral and spring water-based beverages subject to an analysis contents of fructose, glucose and sucrose with the high-performance liquid chromatography method with ELSD detection) and chlorides, nitrates and sulphates contents using the ion chromatography method. RESULTS: A chromatographic analysis has confirmed the total contents of sugar declared by the manufacturers. The carbohydrates identified included fructose, glucose and sucrose (added sugar). Chlorides and sulphates were found in the content of all the analysed beverages while nitrates were not determined in only one of the 15 examined beverages. CONCLUSIONS: Mass consumption of mineral and spring water-based beverages should be considered as an important source of sugar and their excessive consumption may be disadvantageous for human health. A consumer should be informed by a manufacturer about a daily dose of sugar in a portion of a drink in per cents, and the easiest way to do it is to provide GDA marks on the label. Mineral and spring water-based beverages do not pose threats to consumer health in terms of their contents of inorganic ions: chlorides, nitrates and sulphates.