Distribution of mercury in Amanita fulva (Schaeff.) Secr. mushrooms: Accumulation, loss in cooking and dietary intake

Ecotoxicology and Environmental Safety 115 (2015) 49–54

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Distribution of mercury in Amanita fulva (Schaeff.) Secr. mushrooms: Accumulation, loss in cooking and dietary intake Jerzy Falandysz n, Małgorzata Drewnowska Gdańsk University, 63 Wita Stwosza Street, PL 80-952 Gdańsk, Poland

art ic l e i nf o

a b s t r a c t

Article history: Received 28 August 2014 Received in revised form 30 January 2015 Accepted 4 February 2015

Representative individual specimens and pooled samples of carpophores of edible wild-grown fungus Amanita fulva (Schaeff.) Secr. and forest topsoil layer (0–10 cm) beneath the carpophores were collected from 15 spatially distant places in Poland and examined for total Hg. The median values of Hg in soils for most of the sites were below 0.05 mg kg
1 dry matter. The ability of fungus A. fulva to bioconcentrate Hg was low (BCF, bioconcentration factor values of 1.2–3.6 for caps and 0.66–1.7 for stipes) at five sites that showed Hg in soils ranging from 0.066 to 0.21 mg kg
1 dry matter, while much higher bioconcentration (BCF of 11–25 for caps and 7.0–12 for stipes) were observed for less contaminated soils with Hg contents of 0.018–0.054 mg kg
1 dry matter. Differences were also observed in Hg contamination of A. fulva from spatially and distantly distributed sites, and the median values (mg kg
1 dry matter) ranged from 0.13 to 0.67 for caps and from 0.065 to 0.34 for stipes, while 0.63 mg kg
1 dry matter was observed in a set of whole fruiting bodies. Boiling of fresh A. fulva for 10 min reduced the Hg content by 10%. A meal of A. fulva containing 0.065 mg kg
1 of Hg in the fresh mushroom product will not result in exceeding the reference dose set for inorganic Hg and for majority of the sites assessed (4 90%) intake was substantially lower than the reference dose or the provisional tolerable weekly intake of inorganic Hg. & 2015 Elsevier Inc. All rights reserved.

Keywords: Bioconcentration Food contaminants Forest Fungi Mushrooms Soils

1. Introduction The widespread use of Hg and its uncontrolled emission is blamed for its increased environmental loads and hazard (UNEP, 2013). Mercury in the environment undergoes biomethylation to methyl mercury (MeHg), which easily enters the food chain (Olivero et al., 2002). There is a gradient of toxic potency by inorganic and organic bound Hg in compounds and MeHg because of its high toxicity, persistence and biomagnification is the most relevant food and environment contaminant (NRC, 2000). The earth's crust contains Hg in concentration ranging from 0.02 to 0.06 mg kg
1 dry matter (dm) (Kabata-Pendias and Szteke, 2012). Mushrooms both of mycorrhizal and non-mycorrhizal nature are efficient in the mobilization of Hg from soil/litter substratum and its subsequent sequestration within the fruiting bodies. Difference in Hg uptake for different mushroom species may largely be dependent on genetics. It is not clear to which extent the sequestration of Hg can be influenced by environmental factors such as naturally elevated Hg contents of soil bedrock and mushrooms (e.g. as observed for red and yellow soils of Yunnan in China and some mushrooms there; JF, unpublished) and n

Corresponding author. E-mail address: [email protected] (J. Falandysz).

http://dx.doi.org/10.1016/j.ecoenv.2015.02.004 0147-6513/& 2015 Elsevier Inc. All rights reserved.

anthropogenic pollution (Dryżałowska and Falandysz, 2014; Falandysz, 2014; Falandysz and Brzostowski, 2007; Falandysz et al., 2001a, 2001b, 2002a, 2002b, 2002c, 2002d, 2003a, 2003b, 2003c and 2014b; Melgar et al., 2009; Nasr and Arp, 2011; Nasr et al., 2012; Tüzen and Soylak, 2005; Wiejak et al., 2014). Data is scarce on the possible impact of the increasing global Hg loads (Zhang et al., 2013) on Hg occurrence in wild-grown mushrooms. A recent study suggested airborne deposition as the source of elevated Hg in some litter decomposers from the high mountain region of Mt. Gongga of the Eastern Tibetan Plateau (Falandysz et al., 2014a). MeHg in wild grown edible mushrooms can be considered as a minor Hg compound because it is usually found at  5% to  10% of the total Hg (THg) content and only in a few reports was it determined up to 25% – as reviewed by Falandysz et al. (2012a, 2012b). In a recent study by Rieder et al. (2011), the MeHg portion of THg of several species of mushrooms (often a single specimen of the species) was between 0.3% to  16%, and the mean value for mycorrhizal species was 4.8 71.0%, and this is close to the values reported for wood decomposers (5.0 7 1.4%) as well as for litter decomposers (2.8 70.6%). From available data on MeHg and THg in Amanita mushrooms, for Amanita caesarea (Scop.: Fr.) Pers. ex Schw. (n ¼1) (choice edible mushroom), the MeHg component of the THg was 6.8% (THg of 0.35 and MeHg of 0.024 mg kg
1 dm) and MeHg was better bioconcentrated (BCF ¼24) compared to THg (BCF ¼ 5.6) (Rieder

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J. Falandysz, M. Drewnowska / Ecotoxicology and Environmental Safety 115 (2015) 49–54

et al., 2011). In a similar study with limited number of specimens and species by Fischer et al. (1995), the MeHg component of the THg was between 0.40–0.90% in Amanita muscaria (n ¼3) and MeHg was much better bioconcentrated (BCF ¼64–82) than THg (BCF ¼0.48–1.0). Edible carpophores of wild grown fungi are products that show higher content of Hg compared to vegetables, fruits and other kinds of foods of plant origin or slaughtered animals e.g. in a Finnish market (Varo et al., 1980), and rice sampled across China with Hg content of 0.0027 0.002 mg kg
1 (range from non-detected concentration of 0.019 mg kg
1) (Fang et al., 2014). There is a tradition of collection and consumption of mushrooms from the wild and this practice is common in many nations worldwide and in some countries they are also collected for use in traditional medicine (Zhang et al., 2010; Wang et al., 2014). Some mushrooms of the family Amanitaceae, genus Amanita are edible, while many others contain potent organic toxins. Amanita fulva (Schaeff.) Secr. also known as Tawny Grisette or Orange– Brown Ringless Amanita is one of the several edible species of its genus. In the book “The Macrofungi of China” among the listed 78 species of Amanita, the toxicity of 19 species was not indicated or they were just indicated as “unknown”; 39 species, which represent half of all species shown are identified as ‘poisonous’ or ‘possibly poisonous’ while 20 are indicated as “edible” or “conditionally edible” (Xiaolan, 2000). As mentioned earlier, the A. caesarea is an edible mushroom of choice. Other examples of edible Amanita mushroom which are valued and are conditionally edible but largely without data on minerals composition are A. cesarea var. alba Gill.; Amanita ceciliae (Berk. & Br.) Bas; Amanita chepangiana Tulloss & Bhandary; Amanita crocea (Quél. in Bourd.) Singer ex Singer; Amanita esculenta Hongo & Matsuda; Amanita excelsa var. spissa (Fr.) Neville & Poumerat.; A. fulva (Schaeff.: Fr.) Pers. ex Sing.; Amanita hemibapha (Berk. & Br.) Sace.; A. hemibapha subsp. javanica (Berk. & Br.) Sacc. Corber & Bas; A. hemibapha subsp. similis (Berk. & Br.) Sacc. (Boed.) Corner & Bas; Amanita manginiana Hariot et Patouillard; Amanita nivalis Grev.; Amanita pachycolea Stuntz; Amanita ponderosa Malençon & R. Heim 1944; Amanita pseudovaginata Hongo; Amanita rubescens (Pers.: Fr.) Gray; Amanita umbrinolutea Secr.; Amanita vaginata (Bull.: Fr.) Vitt.; Amanita virgineoides Bas; Amanita vittadinii (Moret.) Vitt.; Amanita yuaniana Z. L. Yang. (Index Fungorum, 2013; Moreno–Rojas et al., 2004; Xiaolan, 2000). Studies have shown that mushroom species of the same family or genus vary significantly in Hg contents of their fruiting bodies even when they emerge at unpolluted (background) areas and also of the same species but from different populations (Falandysz et al., 2007a, 2007b, 2007d, 2012c, 2013). The part of the fruiting body bearing spores (hymenophore and more broadly the cap) in matured specimens of many species examined usually contained more Hg than the rest of the fruiting body or the stipe (Alonso et al., 2000; Gucia et al., 2012; Melgar et al., 2009). This can be attributed to the physiological status of this part of the carpophore and this play an important role on Hg intake rate if only caps are consumed (Al Sayegh Petkovšek and Pokorny, 2013). There is no criterion yet that could allow a reasonable prediction of Hg content of the flesh of any species from the wild when using data gotten from another (neighbor) mushroom species at the same place/region or based on the soil (substratum) Hg results. This also applies to any other trace-essential, non-essential or toxic metallic and metalloid elements and non-metals. Meanwhile there is a dearth of reasonable database for many edible species both locally and regionally around the world (Falandysz and Borovička, 2013). This work is part of an ongoing study aimed at examining the elemental composition of edible wild mushrooms, understanding their complex mineral composition and interdependence, and their food value to man. The THg content, accumulation, and

Fig. 1. Location of the sampling sites of A. fulva and soils are marked with spots and number is assigned to each site (1) Nearshore Landscape Park, (2) Puszcza Darżlubska), (3) Wysokie, (4) Strzebielino, (5) Bruskowo Wielkie, (6) Dobieszewo, (7) Commune of Sierakowice, (8) Łapino, (9) Jodłowno, (10) Kozia Góra, (11) Lipusz, (12) Dziemiany, (13) Puszcza Augustowska, (14) Murawiec near Bydgoszcz, (15) Dolnośląskie forests (for more details see Table 1).

distribution in the fruiting bodies of A. fulva in relation to the THg content of soils beneath the mushrooms were assessed in this study. THg leaching during cooking (blanching per 10 min) was also determined and the possible Hg intake (exposure) from consumption of the mushroom estimated while the likely risk to human consumers were also discussed. Mushroom specimens and soils were collected from several distantly distributed sites mainly in the northern part of Poland and from more industrialized and some metal ores rich regions of the southwestern Poland (Fig. 1). The places of sampling are without any documented impact by industrial source of Hg emission.

2. Materials and methods 2.1. Fruiting bodies and soils Matured specimens of A. fulva that are in good condition and soils taken from below the fruiting bodies were collected from 15 spatially distant sites largely in the northern and southern parts of Poland between 2000 and 2013. The regions sampled were the Pomeranian Voivodeship (18,310 km2), Suwalskie region – Augustowska forest (1100 km2) and Lower Silesia – Dolnośląskie forest (1650 km2) (Fig. 1; Table 1). Fruiting bodies – usually separated into caps and stipes, and soil samples were examined individually and in pools. The number of samples and specimens for each site and year are given in Table 1. The bottom part of the stipes were cut off when sampled and if necessary the fruiting bodies were also carefully cleaned up from leaves and other adhered plant debris with plastic knife. Mushrooms were air-dried for 2–3 days at room temperature under clean condition, and then they were dried under clean condition

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Table 1 Total mercury content of A. fulva and beneath soil substratum and values of mercury cap to stipe concentration quotient (QC/S) and bioconcentration factor (BCF) (mg kg
1 dm; arithmetic mean 7SD, range and median value, respectively). Site, year and number of samples

Hg

QC/S

Fruiting bodies

a

(1) Pomerania, Nearshore Landscape Park, 2006 n¼ 15(71)

(2) Pomerania, Puszcza Darżlubska, Piaśnica, 2003 n¼ 15(110)

(3) Pomerania, Commune Łęczyce, Wysokie; 2006 n¼ 15

(4) Pomerania, Commune Łęczyce, Strzebielino, 2006 n¼ 15

(5) Pomerania, Bruskowo Wielkie, Commune Słupsk, 2003 n¼ 15(101)

(6) Pomerania, Commune of Dębnica Kaszubska, Dobieszewo, 2006 n¼10(61)

(7) Pomerania, Commune of Sierakowice, 2007 n ¼15(58)

(8) Pomerania, Łapino, 2007 n ¼15(51)

(8) Pomerania, Łapino, 2011 n¼ 15(84)

(9) Pomerania, Jodłowno, 2011 n¼ 7(120)

(10) Pomerania, Kozia Góra, 2013 n ¼3(14)

(11) Pomerania, Lipusz, 2006 n ¼15

(12) Pomerania, Dziemiany, 2003 n ¼15(43)

(13) Augustów land, Puszcza Augustowska, 2007 n¼ 15

(14) Pomerania, Murawiec near Bydgoszcz, 2000 n ¼15(32)

(15) Lower Silesia, Dolnośląskie forests, 2008 n¼ 15(26)

BCF

Soils

Caps

Stipes

0.56 70.37 0.25–1.5 0.46 0.45 70.10 0.32–0.64 0.43 0.137 0.07 0.057–0.27 0.13 0.41 70.10 0.30–0.58 0.37 0.59 70.22 0.29–0.87 0.67 0.45 70.11 0.28–0.62 0.44 0.52 70.36 0.15–1.4 0.46 0.247 0.08 0.13–0.41 0.22 0.247 0.05 0.16–0.31 0.23 0.647 0.14 0.39–0.82 0.63 0.65 70.01 0.63–0.66 0.65 0.29 70.23 0.036–0.83 0.19 0.34 70.02 0.21–0.58 0.33 0.25 70.12 0.078–0.46 0.23 0.317 0.05 0.25–0.40 0.29 0.36 70.01 0.22–0.56 0.33

0.28 7 0.16 0.12–0.66 0.22 0.22 7 0.04 0.16–0.28 0.21 0.073 70.041 0.029–0.18 0.065 0.217 0.06 0.12–0.35 0.19 0.36 7 0.10 0.23–0.55 0.34 0.217 0.05 0.14–0.32 0.20 0.30 7 0.20 0.086 7 0.65 0.22 0.137 0.05 0.065–0.26 0.12 0.137 0.02 0.090–0.16 0.13

0.025 7 0.010 0.013–0.055 0.021 0.0187 0.001 0.015–0.21 0.018 0.095 7 0.054 0.033–0.22 0.086 0.056 7 0.027 0.019–0.12 0.054 0.034 7 0.036 0.012–0.14 0.024 0.127 0.04 0.049–0.18 0.13 0.157 0.08 0.049–0.27 0.18 0.028 7 0.007 0.016–0.044 0.026 0.020 7 0.048 0.011–0.030 0.019 WD

0.30 7 0.01 0.30–0.31 0.30 0.147 0.10 0.057–0.42 0.11 0.22 7 0.02 0.098–0.47 0.21 0.20 7 0.12 0.086–0.46 0.19 0.167 0.03 0.13–0.21 0.15 0.17 70.08 0.080–0.36 0.15

WD

0.0467 0.026 0.022–0.11 0.036 0.0357 0.004 0.018–0.085 0.029 0.095 7 0.057 0.027–0.21 0.066 0.0427 0.008 0.029–0.057 0.041 0.217 0.07 0.11–0.39 0.21

Caps

Stipes

2.17 0.6 1.1–4.0 2.0 2.17 0.3 1.4–2.9 2.0 1.9 7 0.3 1.1–2.3 2.0 2.0 70.3 1.4–2.6 2.0 1.6 7 0.5 1.0–2.8 1.6 2.17 0.2 1.9–2.5 2.1 1.7 7 0.3 1.1–2.3 1.7 1.9 7 0.2 1.6–2.2 1.9 1.9 7 0.2 1.5–2.5 1.9 WD

267 20 5.9–65 18 257 6 18–34 25 2.0 7 1.7 0.50–6.1 1.2 9.17 5.7 3.0–25 8.3 257 17 2.7–32 20 4.3 7 2.1 1.9–9.2 3.6 5.0 7 6.3 0.69–23 3.0 9.0 7 3.2 4.4–15 9.0 137 4.4 7.1–24 13 WD

137 9 3.1–29 8.9 127 2 8.3–15 12 1.17 0.9 0.22–3.0 0.89 4.6 73.0 1.5–12 3.8 167 9.0 1.6–32 16 2.0 71.0 0.97–4.5 1.7 2.8 73.2 0.40–11 1.7 4.8 71.9 2.3–8.6 4.6 6.6 71.8 3.9–9.8 6.4 WD

2.17 0.1 2.1–2.2 2.2 2.0 70.6 0.41–2.8 2.0 1.6 7 0.1 1.1–2.5 1.6 1.3 7 0.4 0.54–2.0 1.3 1.9 7 0.2 1.7–2.2 1.9 2.5 71.1 1.4–5.4 2.0

WD

WD

7.0 7 6.0 1.6–25 4.9 117 1 2.9–21 11 3.7 7 3.0 0.45–9.2 2.3 7.7 7 2.1 4.4 7 12 7.7 1.9 7 0.8 0.80–4.1 1.7

3.5 72.3 0.63–10 3.1 7.4 7 1.0 1.2–16 7.0 3.2 72.8 0.47–8.1 1.7 4.0 71.1 2.3–5.9 3.9 0.917 0.63 0.38–2.9 0.66

Notes:WD (without data). a

Number of samples and number of specimens (in parentheses).

using electrically heated commercial dryer (for mushrooms and vegetables) for 3–4 days. Dried specimens were further ground in porcelain mortar to fine powder and further kept in sealed polyethylene bags under clean condition until chemical analysis. Before chemical analyses, fungal materials were kept in electrically heated laboratory oven at 65 °C to constant weight. The samples of upper 0–10 cm layer of soils, after removal of plants, small stones and visible organisms were air dried at room temperature under clean condition for several weeks and next sieved through a pore size of 2 mm and kept in sealed polyethylene bags. Before chemical analyses, the soils were kept for

48 h in electrically heated oven at 85 °C. 2.2. Analyses The determination of total Hg content of mushrooms and soils was by direct material thermal decomposition, coupled with trap of vapors by gold wool and desorption and released vapors concentration measurement by method of cold vapor-atomic absorption spectroscopy (CV-AAS). The Mercury analyzer type MA-2 (equipped with auto-sampler) (Nippon Instruments Corporation, Takatsuki, Japan) were employed. Data on reagents, standards and

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method used are given in detail elsewhere (Jarzyńska and Falandysz, 2011; Nnorom et al., 2013). The analytical quality and analytical controlled procedure for Hg determination was performed through routine examination of blank samples and the certified reference material which in this work material is CS-M-1 (dried fruiting bodies of mushroom Cow Bolete Suillus bovinus) with certified value of 0.174 70.018 mg kg
1 dm, while our result was 0.188 70.017 mg kg
1 dm (n¼ 3). Data were evaluated using the computer software Statistica version 8.0 (Statsoft, Inc.). Examination of differences in Hg concentrations of the caps, stipes and soil samples for the sites investigated were made using Mann–Whitney U test.

3. Results and discussion 3.1. THg in soils and mushrooms The forest soil substrates for A. fulva in this study showed statistically significant differences in the spatial distribution and content of THg in the top 0–10 cm layer (po 0.01; Mann–Whitney U test) and for few more contaminated sites was around 0.1 mg/kg dm, while total range for all areas was from 0.018 to 0.21 mg kg
1 dm (median values) (Table 1). For most of the sites examined, the median value of THg in soils was below 0.05 mg kg
1 dm which is considered to be the geochemical background value for soils of Poland though the soil type (agricultural, forest etc) and frequency of sampling were not given (PIG, 2013). For the most contaminated site which is located in the southwestern region of the country, the Lower Silesia forests site (Fig. 1), the median value of THg was 0.21 and maximum value of soil contamination there was 0.39 mg kg
1 dm. An explanation for the higher contamination of that region could be the degree of urbanization and industrialization that now resulted in the emission and contamination with Hg and other anthropogenic pollutants (UNEP, 2013) but also possibly from geochemical anomaly. In earlier studies on Hg in upper 0–10 cm layer of forest soils from the Lower Silesia, the median values were 0.36 and 0.46 mg kg
1 dm, while 0.36 mg kg
1 dm was reported in forested dump site related to an ancient gold and copper mine site (Falandysz et al., 2012a, 2012d; Kojta et al., 2012). In that geographical region, soils from the Mountains Sudety contained THg at 0.14 mg kg
1 dm, and for more eastern located site of Zakopane (Tatra mountains region) was 0.20 mg kg
1 dm (Falandysz et al., 2012a, 2012d). The “background” forested areas worldwide can more or less suffer because of enhanced Hg influx in recent decades (Stankwitz et al., 2012). In this study four sites from the northern part of the country (the Commune of Sierakowice, Łęczyca and Commune Dębica and Augustowska forests; Fig. 1) also showed elevated contents of THg in soils when compared to the background value mentioned, while the median values were from 0.066 to 0.18 mg kg
1 dm. Earlier studies with other species of mushrooms showed a somehow elevated Hg in forest soils of the Commune Sierakowice (Falandysz et al., 2012a). Reasons for this observation are not known and any possible anthropogenic influence could not be identified there. Mushrooms that emerged at the five contaminated sites mentioned were characterized by lower median values of BCF (1.2, 1.7, 2.3, 3.0 and 3.6 for caps and 0.66, 0.89, 1.7, 1.7 and 1.7 for stipes, respectively) compared to other study sites which showed lower contamination of soils and for which the BCF values for caps were up to 11–25 and for stipes up to 7.0–12 (Table 1). The caps of matured (well developed but not necessarily “old” at the time of collection) fruiting bodies of mushrooms in practice always show greater contents of Hg than stipes with median and mean values of QC/S around 1.9–2.5 (Chojnacka et al., 2012; Drewnowska et al.,

2012a, 2012b; Jarzyńska et al., 2012). The mean content of Hg in caps (with the exception of one site with Hg in caps of 0.13 70.07 mg kg
1 dm and in stipes of 0.073 70.041 mg kg
1 dm) were from 0.247 0.06 to 0.657 0.91 mg kg
1 dm (median values of 0.13 and 0.19–0.67 mg kg
1 dm respectively) and for stipes from 0.13 70.05 to 0.36 70.10 mg kg
1 dm (median values: 0.065 and 0.11–0.34 mg kg
1 dm), and for one set of whole fruiting bodies was 0.647 0.14 (median 0.63 mg kg
1 dm) (Table 1). The median values of Hg determined in caps and stipes showed spatial differences (p o0.01; Mann–Whitney U test) in Hg content for some sites while the absolute concentration values differed from 4 to 5 fold (Table 1). In one of two earlier studies available for A. fulva, for specimens collected in 1997/98 in the northern part of Poland, the Hg content of caps was 0.78 70.27 and for stipes 0.397 0.15 mg kg
1 dm (Falandysz et al., 2004), while for mushrooms collected in 2005 in the central part of the country the Hg in caps, stipes and whole fruiting bodies (number of specimens not reported) were 0.12, 0.094 and 0.14 mg kg
1 dm (Szynkowska et al., 2008), and these values are close to the maximum and minimum values of this study, respectively (Table 1). The degree of A. fulva contamination with Hg across Poland is of similar magnitude as for edible A. vaginata (medians of 0.079–0.44 mg kg
1 dm for caps and of 0.041–0.24 mg kg
1 dm for stipes) and on the average these are 2–3 fold higher than for A. rubescens (medians of 0.034 to 0.16 mg kg
1 dm for caps and of 0.021 to 0.12 mg kg
1 dm for stipes) (Drewnowska et al., 2012a, 2014) while fruiting bodies of inedible A. muscaria are more contaminated (the median values of 0.17 to 1.4 mg kg
1 dm for caps and 0.18 to 0.67 mg kg
1 dm for stipes (Falandysz et al., 2007e, 2007f; Drewnowska et al., 2013). Mushrooms should not to be eaten raw but traditionally it sometimes happens like with some traditional recipes with Tricholoma matsutake (China) or with Agaricus bisporus served fresh in “vegetable salad”. Cooking and other processing of mushrooms can impact on their elementary composition resulting in decrease or increase of element content when related to dry matter (Falandysz and Borovička, 2013). For compounds that are almost insoluble in water, such as Hg(II), some processes e.g. blanching seem to have only limited impact on their leaching. 3.2. Cooking experiment A simple cooking experiment was also performed in this study to test the effect of short term blanching (cooking in boiling water for 10 min) of fresh fruiting bodies of A. fulva on the Hg content of the blanched mushrooms (calculated on dry matter content). In this experiment, 120 fruiting bodies were divided in two halves (both cap and stipe) and were made into seven sets and each set consisted of two sub-samples. Each sub-sample in a set consisted of the same number of halves of randomly selected specimens (from 10 to 20 per pool). The Hg content of dried non-blanched fruiting bodies was 0.64 70.14 mg kg
1 (Table 1) while that of the blanched counterparts was 0.58 70.13 mg kg
1 dm (median was 0.60 and range from 0.38 to 0.80 mg kg
1 dm). Hence, in practice there was not more than 10% loss of Hg (per volume/weight of the product per unit of dry matter content). This is because during the 10 min blanching time, there was a loss of a portion of Hg and a corresponding loss of a portion of the water soluble organic constituents (e.g. phenolic compounds, carbohydrates, vitamins, pigments, free amino acids) of fruiting bodies and also of its original moisture. There is a range of recipes and procedures for cooking and preserving mushrooms and both wild-grown species as well as

J. Falandysz, M. Drewnowska / Ecotoxicology and Environmental Safety 115 (2015) 49–54

cultivated species such as Champignon Mushroom (A. bisporus) are also processed at industrial scale (canned, pickled) (Vetter, 2003). With the exception of the conventional drying, other methods of mushrooms cooking/processing probably always result in the leaching of some of the minerals contained in flesh and the rate of leaching may depend on the impact of the process of the disintegration of the cells structure as well as on the solubility of the element under consideration (its chemical form). While the constituents leached out of the fruiting bodies still remains in meal (soup etc. except if discarded), and its composition will depend on the recipe used in the mushroom preparation (Falandysz et al., 2008a, 2008b, 2011; Nnorom et al., 2012; Wang et al., 2014).

53

fruiting bodies compared to staple foods. Data base on Hg and other mineral elements accumulated in edible wild-grown mushrooms from the Europe and other regions of the world is gradually increasing while differences in Hg accumulation pattern and contamination of any given species could vary depending on the site of collection. Until now there is no data available on digestibility and bioavailability of Hg from mushroom meals. Also, there is no data on competitive interrelationships between chalcophile elements sequestered in the flesh by mushroom and sulfur. Nevertheless, the intakes of Hg contained in A. fulva collected from uncontaminated areas and eaten occasionally do not present any health risk to a consumer.

3.3. Hg intake Acknowledgments A meal made of 300 g of fresh mushrooms can be considered appropriate as single portion for an adult consumer of wild-grown mushrooms but sometimes this could even be higher (Chudzyński et al., 2009, 2011; Kalač, 2009). The frequency of wild-grown mushrooms consumption varies highly between individuals and families worldwide. For example during the mushrooming season, fresh wild-grown mushrooms are common among the staple food products in Yunnan province of China (Wang et al., 2014; Zhang et al., 2010). The lowest median value of Hg in caps of A. fulva for the sites investigated is 0.13 mg kg
1 dm (0.013 mg/kg for fresh caps with 90% of moisture) while the highest median value observed is 0.65 mg/kg dm for whole fruiting bodies (0.065 mg/kg fresh product) (Table 1). When assessing intake of Hg from A. fulva the Hg loss of approximately 10% due to leaching could be neglected. Hence, based on the data on median Hg contents, a meal consisting of 300 g of fruiting bodies will provide from around 0.0039–0.0195 mg of Hg. If eaten daily for a week, this will provide from 0.0273 to 0.1365 mg of Hg, assuming no Hg intake from other sources. This total Hg intake if calculated per kilogram of body mass (bm) for a person of 60 kg bm gives a daily dose of 0.000065 and 0.000325 mg kg
1 and weekly dose of 0.000455 and 0.002275 mg kg
1, respectively. A single dose of 0.000325 mg kg
1 is equal to the established reference dose (RfD) for inorganic Hg set at 0.0003 mg kg
1 bm (US EPA, 1987), while a dose of 0.000065 mg kg
1 bm is approximately a fifth of the RfD. The Provisionally Tolerable Weekly Intake (PTWI) of inorganic Hg is 0.004 mg kg
1 bm (JECFA, 2010). As mentioned earlier, a small part of THg in mushrooms is MeHg. Irreversibly bound HgS and HgSe are possible inorganic Hg compounds in THg sequestered in the fruiting bodies of mushrooms, and both are only highly insoluble in water. HgS and HgSe if present, they would be rather hardly bio-accessible from a mushroom meal. Unknown is content of Se in A. fulva. Selenium content of closely related A. vaginata, is around 1 mg kg
1 dm (Falandysz, 2008). Nevertheless, the forms of inorganic Hg in mushrooms are unknown. Nevertheless, assessed rates of Hg intake from A. fulva eaten each day in a week period are below value of PTWI. Some species of mushrooms collected at background (uncontaminated) areas in Europe are often more contaminated with Hg than A. fulva in this study (Falandysz et al., 2007a, 2007b, 2007c; Melgar et al., 2009). Occasional consumption of the fruiting bodies of A. fulva from the regions examined in this study could be considered safe even if it is assumed that the Hg is completely absorbable and accessible to the body.

4. Conclusion A. fulva is another example that shows that many species of wild-grown mushrooms contain elevated Hg concentration in

This study in part was funded by the National Science Centre under Project no. DEC-2012/05/N/NZ9/01561. Article is a part on PhD thesis by Małgorzata Drewnowska. Technical support by students Katarzyna Janukowicz, Aleksandra Mostrąg, Arleta Naczk, Alina Pękacka, Dominika Romińska, Daniel Siwicki, Justyna Wejer, Magdalena Zagajewska, Agnieszka Zając and Marta Zielińska is acknowledged.

References Alonso, J., Salgado, M., Gariciá, M., Melgar, M., 2000. Accumulation of mercury in edible macrofungi: influence of some factors. Arch. Environ. Contam. Toxicol. 38, 158–162. Al Sayegh Petkovšek, S., Pokorny, B., 2013. Lead and cadmium in mushrooms from the vicinity of two large emission sources in Slovenia. Sci. Total Environ. 443, 944–954. Chojnacka, A., Drewnowska, M., Jarzyńska, G., Nnorom, I.C., Falandysz, J., 2012. Mercury in yellow-cracking Boletes Xerocomus subtomentosus mushrooms and soils from spatially diverse sites: assessment of bioconcentration potential by species and human intake. J. Environ. Sci. Health, Part A 47, 2093–3011. Chudzyński, K., Bielawski, L., Falandysz, J., 2009. Mercury bio-concentration potential of Larch Bolete, Suillus grevillei, mushroom. Bull. Environ. Contam. Toxicol. 83, 275–279. Chudzyński, K., Jarzyńska, G., Stefańska, A., Falandysz, J., 2011. Mercury content and bio-concentration potential of Slippery Jack, Suillus luteus, mushroom. Food Chem. 125, 986–990. Drewnowska, M., Jarzyńska, G., Kojta, A.K., Falandysz, J., 2012a. Mercury in European Blusher, Amanita rubescens, mushroom and soil. Bioconcentration potential and intake assessment. J. Environ. Sci. Health, Part B 47, 466–474. Drewnowska, M., Jarzyńska, G., Sąpór, A., Nnorom, I.C., Sajwan, K.S., Falandysz, J., 2012b. Mercury in Russula mushrooms: bioconcentration by yellow-ocher Brittle Gills Russula ochroleuca. J Environ Sci. Health, Part A 47, 1577–1591. Drewnowska, M., Lipka, K., Jarzyńska, G., Danisiewicz-Czupryńska, D., Falandysz, J., 2013. Investigation on metallic elements of Fly Agaric, Amanita muscaria, fungus and the forest soils from the Mazurian Lakes District of Poland. Fresenius Environ. Bull. 22, 455–460. Drewnowska, M., Nnorom, I.C., Falandysz, J., 2014. Mercury in the Tawny Grisette, Amanita vaginata Fr. and soil below the fruiting bodies. J. Environ. Sci. Health, Part B 49, 521–526. Dryżałowska, A., Falandysz, J., 2014. Bioconcentration of mercury by mushroom Xerocomus chrysenteron from the spatially distinct locations: levels, possible intake and safety. Ecotoxicol. Environ. Saf. 107, 97–102. Falandysz, J., 2008. Selenium in edible mushrooms. J. Environ Sci. Health, Part C 26, 256–299. Falandysz, J., 2014. Distribution of mercury in Gypsy Cortinarius caperatus mushrooms from several populations: an efficient accumulator species and estimated intake of element. Ecotoxicol. Environ. Saf. 110, 68–72. Falandysz, J., Borovička, J., 2013. Macro and trace mineral constituents and radionuclides in mushrooms: health benefits and risks. Appl. Microbiol. Biotechnol. 97, 477–501. Falandysz, J., Brzostowski, A., 2007. Mercury and its bioconcentration factors in Poison Pax (Paxillus involutus) from various sites in Poland. J. Environ. Sci. Health, Part A 42, 1095–1100. Falandysz, J., Gucia, M., Frankowska, A., Kawano, M., Skwarzec, B., 2001a. Total mercury in wild mushrooms and underlying soil substrate from the city of Umeå and its surroundings, Sweden. Bull. Environ. Contam. Toxicol. 67, 763–770. Falandysz, J., Szymczyk, K., Ichihashi, H., Bielawski, L., Gucia, M., Frankowska, A., Yamasaki, S., 2001b. ICP/MS and ICP/AES elemental analysis (38 elements) of edible wild mushrooms growing in Poland. Food Addit. Contam. 18 (2001b),

54

J. Falandysz, M. Drewnowska / Ecotoxicology and Environmental Safety 115 (2015) 49–54

503–513. Falandysz, J., Bielawski, L., Kannan, K., Gucia, M., Lipka, K., Brzostowski, A., 2002a. Mercury in wild mushrooms and underlying soil substrate from the great lakes land in Poland. J. Environ. Monit. 4, 473–476. Falandysz, J., Bielawski, L., Kawano, M., Brzostowski, A., Chudzyński, K., 2002b. Mercury in mushrooms and soil from the Wieluńska Upland in South-central Poland. J. Environ. Sci. Health, Part A 37 (2002b), 1409–1420. Falandysz, J., Gucia, M., Skwarzec, B., Frankowska, A., Klawikowska, K., 2002c. Total mercury in mushrooms and underlying soil from the Borecka Forest, Northeastern Poland. Arch. Environ. Contam. Toxicol. 42, 145–154. Falandysz, J., Lipka, K., Gucia, M., Kawano, M., Strumnik, K., Kannan, K., 2002d. Accumulation factors of mercury in mushrooms from Zaborski Lndscape Park, Poland. Environ. Int. 28, 421–427. Falandysz, J., Brzostowski, A., Kawano, M., Kannan, K., Puzyn, T., Lipka, K., 2003a. Concentrations of mercury in wild growing higher fungi and underlying substrate near Lake Wdzydze, Poland. Water Air Soil Pollut. 148, 127–137. Falandysz, J., Lipka, K., Kawano, M., Brzostowski, A., Dadej, M., Jędrusiak, A., Puzyn, T., 2003b. Mercury content and its bioconcentration factors at Łukta and Morąg, Northeastern Poland. J. Agric. Food Chem. 51, 2835–2836. Falandysz, J., Kawano, M., Świeczkowski, A., Brzostowski, A., Dadej, M., 2003c. Total mercury in wild-grown higher mushrooms and underlying soil from Wdzydze Landscape Park, Northern Poland. Food Chem. 81, 21–26. Falandysz, J., Jędrusiak, A., Lipka, K., Kannan, K., Kawano, M., Gucia, M., Brzostowski, A., Dadej, M., 2004. Mercury in wild mushrooms and underlying soil substrate from Koszalin, North-central Poland. Chemosphere 54, 461–466. Falandysz, J., Frankowska, A., Mazur, A., 2007a. Mercury and its bioconcentration factors in King Bolete (Boletus edulis) Bull. Fr. J. Environ. Sci. Health, Part A 42, 2089–2095. Falandysz, J., Gucia, M., Mazur, A., 2007b. Content and bioconcentration factors of mercury by Parasol Mushroom Macrolepiota procera. J. Environ. Sci. Health, Part B 42, 735–740. Falandysz, J., Kunito, T., Kubota, R., Bielawski, L., Mazur, A., Falandysz, J.J., Tanabe, S., 2007c. Selected elements in Brown Birch Scaber Stalk Leccinum scabrum. J. Environ. Sci. Health, Part A 42, 2081–2088. Falandysz, J., Kunito, T., Kubota, R., Brzostowski, A., Mazur, A., Falandysz, J., Tanabe, S., 2007d. Selected elements of Poison Pax Paxillus involutus. J. Environ. Sci. Health, Part A 42, 1161–1169. Falandysz, J., Kunito, T., Kubota, R., Lipka, K., Mazur, A., Falandysz, J., Tanabe, S., 2007e. Selected elements in Fly Agaric Amanita muscaria. J. Environ. Sci. Health, Part A 42, 1615–1623. Falandysz, J., Lipka, K., Mazur, A., 2007f. Mercury and its bioconcentration factors in Fly Agaric (Amanita muscaria) from spatially distant sites in Poland. J. Environ. Sci. Health, Part A 42, 1625–1630. Falandysz, J., Kunito, T., Kubota, R., Bielawski, L., Frankowska, A., Falandysz, J., Tanabe, S., 2008a. Multivariate characterization of elements accumulated in King Bolete Boletus edulis mushroom at lowland and high mountain regions. J. Environ. Sci. Health, Part A 43, 1692–1699. Falandysz, J., Kunito, T., Kubota, R., Gucia, M., Mazur, A., Falandysz, J., Tanabe, S., 2008b. Some mineral constituents of Parasol Mushroom Macrolepiota procera. J. Environ. Sci. Health, Part B 43, 187–192. Falandysz, J., Frankowska, A., Jarzyńska, G., Dryżałowska, A., Kojta, A.K., Zhang, D., 2011. Survey on composition and bioconcentration potential of 12 metallic elements in King Bolete (Boletus edulis) mushroom that emerged at 11 spatially distant sites. J. Environ. Sci. Health, Part B 46, 231–246. Falandysz, J., Kojta, A.K., Jarzyńska, G., Drewnowska, A., Dryżałowska, A., Wydmańska, D., Kowalewska, I., Wacko, A., Szlosowska, M., Kannan, K., Szefer, P., 2012a. Mercury in Bay Bolete Xerocomus badius: bioconcentration by fungus and assessment of element intake by humans eating fruiting bodies. Food Addit. Contam. A 29, 951–961. Falandysz, J., Kowalewska, I., Nnorom, I.C., Drewnowska, M., Jarzyńska, G., 2012b. Mercury in Red Aspen Boletes (Leccinum aurantiacum) mushrooms and the soils. J. Environ. Sci. Health, Part A 47, 1695–1700. Falandysz, J., Nnorom, I.C., Jarzyńska, G., Romińska, D., Damps, K., 2012c. A study of mercury bio-concentration by Puffballs (Lycoperdon perlatum) and evaluation of dietary intake risks. Bull. Environ. Contam. Toxicol. 89, 759–763. Falandysz, J., Widzicka, E., Kojta, A.K., Jarzyńska, G., Drewnowska, M., DanisiewiczCzupryńska, D., Dryżałowska, A., Lenz, E., Nnorom, I.C., 2012d. Mercury in Common Chanterelles mushrooms: Cantharellus spp. update. Food Chem. 133, 842–850. Falandysz, J., Mazur, A., Kojta, A.K., Jarzyńska, G., Drewnowska, M., Dryżałowska, A., Nnorom, I.C., 2013. Mercury in fruiting bodies of dark Honey Fungus (Armillaria solidipes) and beneath substratum soils collected from spatially distant areas. J. Sci. Food Agric. 93, 853–858. Falandysz, J., Dryżałowska, A., Saba, M., Wang, J., Zhang, D., 2014a. Mercury in the fairy-ring of Gymnopus erythropus (Pers.) and Marasmius dryophilus (Bull.) P. Karst. mushrooms from the Gongga Mountain, Eastern Tibetan Plateau. Ecotox. Environ. Saf. 104, 18–22. Falandysz, J., Krasińska, G., Pankavec, S., Nnorom, I.C., 2014b. Mercury in certain Boletus mushrooms from Poland and Belarus. J. Environ. Sci. Health, Part B 49, 90–695. Fang, Y., Sun, X., Yang, W., Ma, N., Xin, Z., Fu, J., Liu, X., Liu, M., Mariga, A.M., Zhu, X., Hu, Q., 2014. Concentrations and health risks of lead, cadmium, arsenic, and mercury in rice and edible mushrooms in China. Food Chem. 147, 147–150. Fischer, R.G., Rapsomanikis, S., Andreae, M.O., Baldini, F., 1995. Bioaccumulation of methylmercury and transformation of inorganic mercury by macrofungi. Environ. Sci. Technol. 29, 993–999.

Gucia, M., Kojta, A.K., Jarzyńska, G., Rafał, E., Roszak, M., Osiej, I., Falandysz, J., 2012. Multivariate analysis of mineral constituents of edible Parasol Mushroom (Macrolepiota procera) and soils beneath fruiting bodies collected from Northern Poland. Environ. Sci. Pollut. Res. 19, 416–431. Index Fungorum, 2013. 〈http://www.indexfungorum.org/Names/Names.asp〉 (retrieved on 31.10.13.). Jarzyńska, G., Falandysz, J., 2011. The determination of mercury in mushrooms by CV-AAS and ICP-AES techniques. J. Environ. Sci. Health, Part A 46, 569–573. Jarzyńska, G., Chojnacka, A., Dryżałowska, A., Nnorom, I.C., Falandysz, J., 2012. Concentrations and bioconcentration factors of minerals by yellow-cracking Bolete (Xerocomus subtomentosus) mushroom collected in Noteć Forest, Poland. J. Food Sci. 77, H202–H206. JECFA., 2010. Joint FAO/WHO Expert Committee on Food Additives. Seventy-second meeting. Rome, 16–25 February 2010. Summary and Conclusions. JECFA/72/SC. 2010, Food and Agriculture Organization of the United Nations World Health Organization (Issued 16th March 2010). Kabata-Pendias, A., Szteke, B., 2012. Pierwiastki śladowe w geo- i biosferze. Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy, Puławy (ISBN -978-83-7562-120-4). Kalač, P., 2009. Chemical composition and nutritional value of European species of wild growing mushrooms: a review. Food Chem. 113, 9–16. Kojta, G., Jarzyńska, G., Falandysz, J., 2012. Mineral composition and heavy metal accumulation capacity of Bay Bolete (Xerocomus badius) fruiting bodies collected near a former gold and copper mining area. J. Geochem. Explor. 121, 76–82. Melgar, M.J., Alonso, J., Garcia, M.Á, 2009. Mercury in edible mushrooms and soil. Bioconcentration factors and toxicological risk. Sci. Total Environ. 407, 5328–5334. Moreno-Rojas, R., Diaz-Valverde, M.A., Moreno Arrovo, B., Gonzalez, T.J., Capote, C.J. B., 2004. Mineral content of gurumelo (Amanita ponderosa). Food Chem. 85 (2004), 325–330. Nasr, M., Arp, P.A., 2011. Hg concentrations and accumulations in fungal fruiting bodies, as influenced by forest soil substrates and moss carpets. Appl. Geochem. 26, 1905–1917. Nasr, M., Malloch, D.W., Arp, P.A., 2012. Quantifying Hg within ectomycorrhizal fruiting bodies, from emergence to senescence. Fungal Biol. 116, 1163–1177. Nnorom, I.C., Jarzyńska, G., Falandysz, J., Drewnowska, M., Okoye, I., Oji-Nnorom, Ch G., 2012. Occurrence and accumulation of mercury in two species of wild grown Pleurotus mushrooms from Southeastern Nigeria. Ecotoxicol. Environ. Saf. 84, 78–83. Nnorom, I.C., Jarzyńska, G., Drewnowska, M., Kojta, A.K., Pankavec, S., Falandysz, J., 2013. Trace elements in sclerotium of Pleurotus tuber-regium (Ósu) mushroom-dietary intake and risk in Southeastern Nigeria. J. Food Compos. Anal. 29, 73–81. NRC, 2000. Toxicological Effects of Methylmercury. National Academies Press, National Research Council (U.S.) – Board on Environmental Studies and Toxicology, University of California, Riverside, California (ISBN 978-0-309-07140-6). Olivero, J., Johnson, B., Arguello, E., 2002. Human exposure to mercury in San Jorge river basin, Colombia (South America). Sci. Total Environ. 289, 41–47. PIG, 2013. 〈http://www.mapgeochem.pgi.gov.pl/poland/index.html〉. Rieder, S.R., Brunner, I., Horvat, M., Jacobs, A., Frey, B., 2011. Accumulation of mercury and methylmercury by mushrooms and earthworms from forest soils. Environ. Pollut. 159, 2861–2869. Stankwitz, C., Kaste, J.M., Friedlands, A., 2012. Threshold increases in soil lead and mercury from tropospheric deposition across an elevational gradient. Environ. Sci. Technol. 46, 8061–8068. Szynkowska, M.I., Pawlaczyk, A., Albińska, J., Paryjczak, T., 2008. Comparison of accumulation ability of toxicologically important metals in caps and stalks in chosen mushrooms. Pol. J. Chem. 82, 313–319. Tüzen, M., Soylak, M., 2005. Mercury contamination in mushroom samples from Tokat, Turkey. Bull. Environ. Contam. Toxicol. 74, 968–972. UNEP, 2013. Mercury – time to act. United Nations Environmental Programme, 2013. 〈http://www.unep.org/PDF/PressReleases/Mercury_TimeToAct.pdf〉. US EPA., 1987. United States Environmental Protection Agency Peer Review Workshop on Mercury Issues. Summary Report. Environmental Criteria and Assessment Office. Cincinnati, OH: U.S. EPA, October 26–27. Varo, P., Lähelmä, O., Nuurtamo, M., Saari, E., Koivistoinen, P., 1980. Mineral element composition of Finnish foods. VII. Potato, vegetables, fruits, berries, nuts and mushrooms. Acta Agric. Scand. Suppl. 22, S89–S113. Vetter, J., 2003. Chemical composition of fresh and conserved Agaricus bisporus mushroom. Eur. Food Res. Technol. 217, 10–12. Wang, X., Zhang, J., Wu, L., Zhao, Y., Li, T., Li, J., Wang, Y., Liu, H., 2014. A mini-review of chemical composition and nutritional value of edible wild-grown mushroom from China. Food Chem. 151, 279–285. Wiejak, A., Wang, Y., Zhang, J., Falandysz, J., 2014. Bioconcentration potential and contamination with mercury of pantropical mushroom Macrocybe gigantea. J. Environ. Sci. Health, Part B 49, 811–814. Xiaolan, M. The Macrofungi in China, 2000, Henan Science and Technology Press, Zhengzhou, Beijing. Zhang, D., Frankowska, A., Jarzyńska, G., Kojta, A.K., Drewnowska, M., Wydmańska, D., Bielawski, L., Wang, J., Falandysz, J., 2010. Metals of King Bolete (Boletus edulis) collected at the same site over two years. African J. Agric. Res. 5, 3050–3055. Zhang, H., Yin, R.-S., Feng, X.-B., Sommar, J., Anderson, C.W.N., Sapkota, A., Fu, X.-W., Larssen, T., 2013. Atmospheric mercury inputs in montane soils increase with elevation: evidence from mercury isotope signatures. Sci. Rep. 3, 3322. http: //dx.doi.org/10.1038/srep03322.