Martyna Saba

Evaluation of the mercury contamination in mushrooms of genus Leccinum from two different regions of the world: Accumulation, distribution and probable dietary intake.

This study focused on investigation of the accumulation and distribution of mercury (Hg) in mushrooms of the genus Leccinum that emerged on soils of totally different geochemical bedrock composition. Hg in 6 species from geographically diverse regions of the mercuriferous belt areas in Yunnan of SW China, and 8 species from the non-mercuriferous regions of Poland in Europe was measured. Also assessed was the probable dietary intake of Hg from consumption of Leccinum spp., which are traditional organic food items in SW China and Poland. The results showed that L. chromapes, L. extremiorientale, L. griseum and L. rugosicepes are good accumulators of Hg and the sequestered Hg in caps were up to 4.8, 3.5, 3.6 and 4.7 mg Hg kg(-1) dry matter respectively. Leccinum mushrooms from Poland also efficiently accumulated Hg with their average Hg content being an order of magnitude lower due to low concentrations of Hg in forest topsoil of Poland compared to the elevated contents in Yunnan. Consumption of Leccinum mushrooms with elevated Hg contents in Yunnan at rates of up to 300 g fresh product per week during the foraging season would not result in Hg intake that exceeds the provisional weekly tolerance limit of 0.004 mg kg(-1) body mass, assuming no Hg ingestion from other foods.

Evaluation of Mercury Contamination in Fungi Boletus Species from Latosols, Lateritic Red Earths, and Red and Yellow Earths in the Circum-Pacific Mercuriferous Belt of Southwestern China.

For the first time, highly elevated levels of mercury (Hg) have been documented for several species of the edible Fungi genus Boletus growing in latosols, lateritic red earths, and red and yellow earths from the Yunnan province of China. Analysis of Hg concentrations in the genus suggests that geogenic Hg is the dominant source of Hg in the fungi, whereas anthropogenic sources accumulate largely in the organic layer of the forest soil horizon. Among the 21 species studied from 32 locations across Yunnan and 2 places in Sichuan Province, the Hg was found at elevated level in all samples from Yunnan but not in the samples from Sichuan, which is located outside the mercuriferous belt. Particularly abundant in Hg were the caps of fruiting bodies of Boletus aereus (up to 13 mg kg-1 dry matter), Boletus bicolor (up to 5.5 mg kg-1 dry matter), Boletus edulis (up to 22 mg kg-1 dry matter), Boletus luridus (up to 11 mg kg-1 dry matter), Boletus magnificus (up to 13 mg kg-1 dry matter), Boletus obscureumbrinus (up to 9.4 mg kg-1 dry matter), Boletus purpureus (up to 16 mg kg-1 dry matter), Boletus sinicus (up to 6.8 mg kg-1 dry matter), Boletus speciosus (up to 4.9mg kg-1 dry matter), Boletus tomentipes (up to 13 mg kg-1 dry matter), and Boletus umbriniporus (up to 4.9 mg kg-1 dry matter). Soil samples of the 0–10 cm topsoil layer from the widely distributed locations had mercury levels ranging between 0.034 to 3.4 mg kg-1 dry matter. In Yunnan, both the soil parent rock and fruiting bodies of Boletus spp. were enriched in Hg, whereas the same species from Sichuan, located outside the mercuriferous belt, had low Hg concentrations, suggesting that the Hg in the Yunnan samples is mainly from geogenic sources rather than anthropogenic sources. However, the contribution of anthropogenically-derived Hg sequestered within soils of Yunnan has not been quantified, so more future research is required. Our results suggest that high rates of consumption of Boletus spp. from Yunnan can deliver relatively high doses of Hg to consumers, but that rates can differ widely because of large variability in mercury concentrations between species and locations.

Mercury contamination of fungi genus Xerocomus in the Yunnan province in China and the region of Europe

This article presents the results of the study on accumulation, distribution, contamination and probable dietary intake of total mercury (THg) in fruiting bodies of several species of Fungi genus Xerocomus, which emerged in the circum-Pacific mercuriferous belt region in southwestern China in Yunnan and beyond of the mercuriferous belts in the region of Europe. The mushrooms X. puniceus (Boletus amygdalinus), X. spadiceus (Boletus ferrugineus) and X. versicolor (X. rubellus) were from the Yunnan land, and X. badius (Boletus badius) was from the region of Europe in Belarus and X. badius, X. chrysenteron, X. ferrugineus, X. versicolor (X. rubellus) and X. subtomentosus from Poland. The THg in the fungal and soil materials was determined using validated method by cold-vapour atomic absorption spectroscopy. Estimated was also probable dietary intake and health risk from THg in Xerocomus spp. examined by consumers. The data showed that THg content of Xerocomus spp. emerged in the European localizations in Poland and Belarus is at an order of magnitude lower level than determined in samples from the Yunnan Province. A reason for an elevated content of THg in mushrooms from Yunnan can be related to abundance of Hg in the geochemical background of soils there. The assessed doses showed that a single meal composed of 300 g of fresh fruiting bodies of X. spadiceus from the Wuding localization in Yunnan in China if consumed once a week will provide THg at dose close to the provisional tolerable weekly intake (PTWI) value set for THg, while doses will be lower for all other localizations in Yunnan and Europe. In the Wuding localization in Yunnan a frequent consumption of X. spadiceus in volume exceeding 300 g of fresh fruiting bodies per week will provide THg at a dose exceeding the value of PTWI.

Evaluation of vulnerability of Suillus variegatus and Suillus granulatus mushrooms to sequester mercury in fruiting bodies

ABSTRACT This work determined the mercury (Hg) contents and bioconcentration potential of two Suillus mushrooms, and the probable dietary intake of this element from a mushroom meal. The determination of total Hg content of fungal and soil samples was performed using cold-vapour atomic absorption spectroscopy by a direct sample thermal decomposition coupled with gold wool trap of Hg and its further desorption and quantitative measurement at a wavelength of 253.7 nm. The median values of Hg contents (mg kg−1 dry biomass) in 213 specimens of S. variegatus from 12 background areas varied widely from 0.087 to 0.51 for caps and from 0.041 to 0.24 for stipes. In 52 specimens of S. granulatus, the Hg contents ranged from 0.30 to 0.41 for caps and from 0.058 to 0.14 for stipes. Both species could be classified as moderate accumulators of Hg and the median bioconcentration factor values ranged from 7.0 to 14 (caps) and 2.1 to 13 (stipes) for S. variegatus and 9.5 (caps) and 1.3 (stipes) for S. granulatus. The estimated intake rates of Hg with the consumption of 300-g caps were from 0.0026 to 0.015 per capita or from 0.000037 to 0.00022 mg kg−1 body mass and this do not indicate any cause for concern associated with eating a meal once or more in a week during the mushrooming season.

Preferential accumulation of inorganic elements in Amanita muscaria from North-eastern Poland

ABSTRACT Concentrations of Al, Ba, Cd, Ca, Co, Cu, Fe, K, Mg, Mn, Hg, Rb, Ag, Na, Sr and Zn were analysed in fruiting bodies of A. muscaria. This mushroom is considered conditionally edible, since parboiling can detoxify its fruiting bodies from the hallucinogens and render it edible. The specific purpose of the research is the little-known phenomenon of the variability of mineral composition of mushrooms for generations harvested in the same forest areas – both in terms of their nutritional value and anthropogenic influences. Fungal materials were digested in nitric acid and analysed by a validated methods using inductively coupled plasma optical emission spectrometer (ICP-OES) and cold – vapor atomic absorption spectroscopy (CV-AAS). A. muscaria collected in the same area over the period of four years showed fluctuations in the concentrations of the essential elements Co, Cu, Fe, K, Mn, Na and Zn (p < 0.05; U Mann-Whitney test), while only Ca and Mg (p > 0.05) levels were similar. In addition, concentrations of Ag, Al, Ba, Cd, Rb and Sr in fruiting bodies fluctuated, while remained at a similar level for Hg. It is important to note that statistically significant variations in levels of several inorganic elements accumulated in A. muscaria would imply a more careful consideration would be required when assessing the nutritional value of mushroom species.