Risk Assessment of Potential Food Chain Threats from Edible Wild Mushrooms Collected in Forest Ecosystems with Heavy Metal Pollution in Upper Silesia, Poland

Can the concentration of elements in wild-growing mushrooms be deduced from the taxonomic rank?

The mineral composition of wild-growing mushroom species is influenced by various environmental factors, particularly the chemical properties of the soil/substrate. We hypothesised that element uptake might also correlate with taxonomic classification, potentially allowing us to predict contamination levels based on mushrooms within the same taxonomic rank. This study compared the mineral composition (Ag, As, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se, and Zn) of 16 saprotrophic mushroom species from 11 genera across 4 families and 2 orders. Among these were 13 edible and 3 inedible mushrooms, all collected from natural, wild stands in a forest in central-western Poland between 2017 and 2020. Phallus impudicus exhibited the highest mean content of Ba (together with Phallus hadriani) (6.63 and 8.61 mg kg-1, respectively), Ca (with Paralepista gilva and Stropharia rugosoannulata) (803, 735 and 768 mg kg-1, respectively), Cd (with Lycoperdon perlatum) (3.59 and 3.12 mg kg-1, respectively), Co (0.635 mg kg-1), and Fe (with P. hadriani and S. rugosoannulata) (476, 427 and 477 mg kg-1, respectively), while Macrolepiota mastoidea showed the highest content of Ag (1.96 mg kg-1), As (with Coprinus comatus) (1.56 and 1.62 mg kg-1, respectively) and Cu (with Macrolepiota procera and Chlorophyllum rhacodes) (192, 175 and 180 mg kg-1, respectively). Comparing the content of the analysed elements in the genera represented by at least two species, a similarity was observed, the same as the mean concentration in soil under these species. Soil characteristics could be a superior factor that overshadows the impact of the mushroom genus on the elements accumulation, obscuring its role as a determinant in this process. The results are not definitive evidence that belonging to a particular taxonomic rank is a prerequisite condition affecting the accumulation of all elements. A closer focus on this issue is needed.

Selected detrimental and essential elements in fruiting bodies of culinary and toxic medicinal macroscopic fungi growing in the Bohemian Forest, the Czech Republic

Selected wild-growing edible fungi (Boletus edulis, Neoboletus luridiformis, Cantharellus cibarius, Macrolepiota procera, Amanita rubescens, Russula virescens, Lycoperdon perlatum, and Flammulina velutipes) along with the poisonous medicinal species Amanita muscaria were collected from five sites in the Bohemian Forest, the Czech Republic and analyzed regarding the contents of 19 elements (Ag, Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Li, Mg, Mn, Ni, Pb, Rb, Se, Tl, and Zn) in their fruiting bodies. The contents of the elements as well as bioconcentration factors (ratios of the element content in dry matter of the mushroom to the content in the soil; BCF) were significantly species dependent. In general, the analysis revealed the most intensive accumulation of Cd, Rb, Ag, Cu, Se, and Zn in the studied mushrooms. B. edulis accumulated Ag, Se, Cd, Rb, Cu, and Zn with average BCF of 31, 25, 18, 13, 3.9, and 2.6, respectively. On the other hand, A. rubescens accumulated Cd, Rb, Ag, Cu, Zn, and As (BCF of 41, 27, 4.8, 3.3, 2.1, and 1.4). The data concerning the detrimental elements in sporocarps of edible mushrooms indicate no negative effect on human health if the fungi are consumed occasionally or as a delicacy.

Mineral composition variation in Boletales mushrooms-indication of soil properties and taxonomic influence

The efficiency of element accumulation depends on numerous factors, where the physico-chemical characteristics of the soil seem to be very important, and the role of taxonomic rank in the accumulation of elements by mushrooms seems to be important. The aim of the study was to compare the mineral composition of 7 species belonging to Leccinum and Suillus genera, collected between 2019 and 2021 from localizations in the west-central part of Poland. The research aimed to indicate the role of selected soil parameters in stimulating/inhibiting the accumulation of elements by selected Boletales mushroom species and to answer the question about the role of species belonging to the genus as an indicator determining the specific mineral composition of fruiting bodies. Soil pH and other soil properties (granulometric composition, organic carbon, degree of organic matter decomposition) may significantly affect mushrooms' mineral composition. Mushroom species belonging to Leccinum genus exhibited the higher amount of essential major and trace elements than species of Suillus genus). It suggests that the affiliation of the studied mushroom species to a specific genus may affect their mineral composition, and the physicochemical properties of the soil may be responsible for the lack of a clear division in the efficiency of element(s) accumulation. Selected species contain high amounts of K, Cu, Fe, and Zn, while others, such as selected Suillus gravellei fruiting bodies, also contain As and Cd. The results described serve as an introduction to a broader scientific discussion and require many further studies to confirm the role of taxonomic ranks and the influence of soil characteristics on the accumulation of elements by fruiting bodies.

Uptake of toxic and nutrient elements by foraged edible and medicinal mushrooms (sporocarps) throughout Connecticut River Valley, New England, USA

Foraging for edible and medicinal mushrooms is a cultural and social practice both globally and in the United States. Determining the toxic and nutrient element concentrations of edible and medicinal mushrooms is needed to ensure the safe consumption of this food source. Our research examined wild, foraged mushrooms in New England, USA to assess nutrient (Ca, K, Mg, P) and toxic (As, Hg, Pb, Cd) element relationships between mushrooms, substrates, and soils. We examined a gradient in nutrient and toxic elements from more rural Mountain and Hill Zones in Massachusetts, Vermont, and New Hampshire to more developed and urban Valley and Coastal Zones in Connecticut. Substrates and mineral soils were moderate to weak predictors of mushroom tissue concentrations. We found significant differences in nutrient and toxic element concentration among the five common genera: Ganoderma, Megacollybia, Pluteus, Pleurotus, and Russula. In particular, Pluteus had consistently higher toxic element concentrations while Pleurotus and Russula had the highest Bioaccumulation Factors (BAFs). We found that the urban areas of the Valley and Coastal zones of Connecticut had Cd Target Hazard Quotient (THQ) values and ΣTHQ values > 1.0, indicating potential non-carcinogenic health hazard. However, the trend was largely driven by the > 2.0 Cd THQ for Pluteus. Our results suggest that foraging in more urban areas can still yield mushrooms with safe concentrations of toxic elements and abundant nutrients. Further research of this kind needs to be conducted within this region and globally to ensure humans are consuming safe, foraged mushrooms.

Health risks of heavy metals in food and their economic burden in Armenia

Mining leads to excessive heavy metal contamination of agricultural products in Armenia and can adversely impact human health. We quantify the concentrations of toxic heavy metals (lead, nickel, cadmium, and mercury) in food sampled from local markets of the capital city, Yerevan. We combine these measured concentrations with data from a diet survey of 1,195 people. The results provide an estimate of people's heavy metal intake in a typical day. The study finds that only dietary exposure to lead raises consumer safety concerns. More than 50 % of the population have daily intakes of lead that exceed the benchmark dose level (BMDL10) of 0.63 μg/kg b.w./day established by European Food Safety Authority. Moreover, risk assessment results indicate that approximately 96 % of the population has dietary exposure values for lead that exceed the threshold level, with animal products as the primary source. The lead exposure observed in sampled population has the potential to increase blood pressure on average by 0.54 mmHg, lower IQ levels by 1.2 point, and reduce lifetime earnings by $5000. The study reveals a strong need to determine the specific pathways by which lead enters the food supply, to mitigate the excess exposures, and to reduce the potential or severity of the resulting adverse health impacts.

Mycoremediation of Flotation Tailings with Agaricus bisporus

Due to their enzymatic and bioaccumulation faculties the use of macromycetes for the decontamination of polluted matrices seems reasonable for bioremediation. For this reason, the aim of our study was to evaluate the mycoremediation ability of Agaricus bisporus cultivated on compost mixed with flotation tailings in different quantities (1, 5, 10, 15, and 20% addition). The biomass of the fruit bodies and the content of 51 major and trace elements were determined. Cultivation of A. bisporus in compost moderately polluted with flotation tailings yielded significantly lower (the first flush) and higher (the second flush) biomass of fruit bodies, compared with the control treatment. The presence of toxic trace elements did not cause any visible adverse symptoms for A. bisporus. Increasing the addition of flotation tailings to the compost induced an elevated level of most determined elements. A significant increase in rare earth elements (both flushes) and platinum group elements (first flush only) was observed. The opposite situation was recorded for major essential elements, except for Na and Mg in A. bisporus from the second flush under the most enriched compost (20%). Nevertheless, calculated bioaccumulation factor values showed a selective accumulation capacity—limited for toxic elements (except for Ag, As, and Cd) and the effective accumulation of B, Cu, K, and Se. The obtained results confirmed that A. bisporus can be used for practical application in mycoremediation in the industry although this must be preceded by larger-scale tests. This application seems to be the most favorable for media contaminated with selected elements, whose absorption by fruiting bodies is the most efficient.

Evaluation of Aerogel Spheres Derived from Salix psammophila in Removal of Heavy Metal Ions in Aqueous Solution

Heavy metal wastewater treatment is a huge problem facing human beings, and the application degree of Salix psammophila resources produced by flat stubble is low. Therefore, it is very important to develop high-value products of Salix psammophila resources and apply them in the removal heavy metal from effluent. In this work, we extracted the cellulose from Salix psammophila, and cellulose nanofibers (CNFs) were prepared through TEMPO oxidation/ultrasound. The aerogel spheres derived from Salix psammophila (ASSP) were prepared with the hanging drop method. The experimental results showed that the Cu(II) adsorption capacity of the ASSP composite (267.64 mg/g) doped with TOCNF was significantly higher than that of pure cellulose aerogel spheres (52.75 mg/g). The presence of carboxyl and hydroxyl groups in ASSP enhanced the adsorption capacity of heavy metals. ASSP is an excellent heavy metal adsorbent, and its maximum adsorption values for Cu(II), Mn(II), and Zn(II) were found to be 272.69, 253.25, and 143.00 mg/g, respectively. The abandoned sand shrub resource of SP was used to adsorb heavy metals from effluent, which provides an important reference value for the development of forestry in this sandy area and will have a great application potential in the fields of the adsorption of heavy metals in soil and antibiotics in water.

Ameliorative Effects of Exogenous Proline on Photosynthetic Attributes, Nutrients Uptake, and Oxidative Stresses under Cadmium in Pigeon Pea (Cajanus cajan L.)

Proline plays a significant role in the plant response to stress conditions. However, its role in alleviating metal-induced stresses remains elusive. We conducted an experiment to evaluate the ameliorative role of exogenous proline on cadmium-induced inhibitory effects in pigeon pea subjected to different Cd treatments (4 and 8 mg/mL). Cadmium treatments reduced photosynthetic attributes, decreased chlorophyll contents, disturbed nutrient uptake, and affected growth traits. The elevated activity of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase), in association with relatively high contents of hydrogen peroxide, thiobarbituric acid reactive substances, electrolyte leakage, and endogenous proline, was measured. Exogenous proline application (3 and 6 mM) alleviated cadmium-induced oxidative damage. Exogenous proline increased antioxidant enzyme activities and improved photosynthetic attributes, nutrient uptake (Mg²⁺, Ca²⁺, K⁺), and growth parameters in cadmium-stressed pigeon pea plants. Our results reveal that proline supplementation can comprehensively alleviate the harmful effects of cadmium on pigeon pea plants.