A Simple and Rapid Method for Reducing Radiocesium Concentrations in Wild Mushrooms ( Cantharellus and Boletus ) in the Course of Cooking

Conceptualization of the comprehensive phyto-radiotoxicity incurred by radiocesium and strategies to expunge the metal using biotechnological and phytoremediative approaches

Agricultural pollution with 137Cs is an ecological threat due to its sustained half-life and radioactivity. Release of radiocesium isotopes after major nuclear power plant accidents like the Fukushima Dai-ichi and the Chernobyl nuclear power plant disasters have severely affected the surrounding growth of agricultural crops and vegetables cultivated across extensive areas. Even years after the nuclear accidents, biosafety in these agricultural fields is still questionable. Due to similarity in charge and ionic radius between radiocesium and K+, the radionuclides are promiscuously uptaken via K+ channels expressed in plants. Bioaccumulation of radiocesium reportedly promotes physiological and anatomical anomalies in crops due to radiation and also affects the rhizospheric architecture. Due to radiation hazard, the ecological balance and quality are compromised and ingestion of such contaminated food results in irreversible health hazards. Recently, strategies like exogenous supplementation of K+ or genetic engineering of K+ channels were able to reduce radiocesium bioaccumulation in plants taking the advantage of competition between radiocesium and K+ translocation. Furthermore, bioremediation strategies like phycoremediation, mycoremediation, phytoremediation and rhizofiltration have also showed promising results for removing radiocesium from polluted sites. It has been proposed that these eco-friendly ways can be adopted to de-pollute the contaminated sites prior to subsequent cultivation of crops and vegetables. Hence it is essential to: 1) understand the basic radiotoxic effects of radiocesium on agricultural crops and surrounding vegetation and, 2) design sustainable ameliorative strategies to promote radiocesium tolerance for ensuring food and social security of the affected population.

Effect of drying, blanching, pickling and maceration on the fate of 40K, total K and 137Cs in bolete mushrooms and dietary intake

The effects of blanching, blanching and pickling and maceration on the leaching of ¹³⁷Cs and ⁴⁰K from the flesh of three edible bolete mushroom species-Boletus edulis, Leccinum scabrum and Leccinum versipelle-were investigated. Significant (p < 0.05) decreases in activity were observed but varied depending on the treatment. Relative to fresh mushrooms, blanching decreased the activity concentration of ¹³⁷Cs by 15 ± 13%, and of ⁴⁰K, by 16 ± 7%, but blanching and pickling (vinegar) reduced activity more effectively, by 55 ± 8% and 40 ± 20% respectively. The corresponding losses of ¹³⁷Cs and ⁴⁰K through maceration of dried, powdered mushrooms were 38 ± 11% and 35 ± 14% ww, respectively. These results indicate that traditional domestic processing methods may not be as efficient at excluding ¹³⁷Cs radioactivity as shown in some other studies. The activity concentration of ¹³⁷Cs in a typically sized (100 g) portion of a processed mushroom (sourced from nearshore regions of the southern Baltic Sea coast near Gdańsk in 2015) meal was projected to be low, i.e. in the range of 0.51 to 12 Bq kg^-1 ww. The corresponding effective dose of ¹³⁷Cs from blanched, blanched and pickled and macerated mushrooms per capita was also assessed to be low, from 0.001 to 0.010 μSv. Nutritionally, the median concentration of potassium (330 mg) in 100 g portions of blanched or pickled mushrooms would account for around 7% of the adequate adult daily intake.

137Caesium, 40K and total K in Boletus edulis at different maturity stages: Effect of braising and estimated radiation dose intake

We studied activity concentrations of artificial ¹³⁷Cs and natural ⁴⁰K and concentration of total potassium (K) in Boletus edulis at different maturity stages (button, young - white, large - white and large - yellow), and the effect of braising and human dietary intake. Mushrooms were collected from the northern region of Poland in 2019. The ¹³⁷Cs activity concentration was significantly higher in raw and braised button stage samples and decreased as the fruitbody matured, but conversely, ⁴⁰K was lower in the raw button stage than in older fruitbodies. ¹³⁷Cs activity concentrations in raw, button stage B. edulis were 36 ± 1 Bq kg^-1 ww (360 ± 1 Bq kg^-1 dw), increasing to 70 ± 2 Bq kg^-1 ww (290 ± 7 Bq kg^-1 dw) when braised. This activity was around fourteen-fold higher (p < 0.0001) than at higher maturity stages which showed 2.5 ± 0.7 Bq kg^-1 ww (25 ± 7 Bq kg^-1 dw) in raw and 4.9 ± 0.7 Bq kg^-1 ww (19 ± 4 Bq kg^-1 dw) in braised fruitbodies. In comparison to raw B. edulis, braising enriched the activity concentrations of ¹³⁷Cs at 110 ± 69% and ⁴⁰K at 80 ± 56% on a whole (wet) weight basis.

The effects of different cooking modes on the 137Cs, 40K, and total K content in Boletus edulis (King Bolete) mushrooms

This study aimed to get an insight into the effects of household processing on the leaching behaviour of ¹³⁷Cs and ⁴⁰K from fresh, frozen and dried Boletus edulis (King Bolete) mushrooms. Three processes were investigated-blanching, blanching and pickling, and drying followed by grinding and soaking. The activity concentrations of ¹³⁷Cs and ⁴⁰K in the fresh unprocessed mushrooms were 270 Bq kg^-1 dry biomass (27 Bq kg^-1 whole weight) and 590 Bq kg^-1 db (59 Bq kg^-1 ww), respectively. Blanching of fresh mushrooms decreased ¹³⁷Cs activity by 55%, and ⁴⁰K activity by 34%, and blanching of deep-frozen mushrooms caused a reduction of 52% and 44% (db) (equivalent to whole weight reductions of 37% and 8.5%, and 67% and 22%, respectively). Blanching and pickling of fresh mushrooms decreased ¹³⁷Cs activity by 83% and ⁴⁰K activity by 87%, while blanching deep-frozen mushrooms resulted in decreases of 88% and 80% (db) (whole weight decreases of 77% and 81%, and by ~ 84% and 72%, respectively). This study confirms earlier reports that blanching of fresh or frozen mushrooms alone is not as efficient at removing ¹³⁷Cs as blanching followed by pickling. The study also shows that the initial rate of fruiting body disintegration and pre-preparation (comparing fresh, deep-frozen, or dried and ground) can have an impact on the leaching rate of the water soluble fraction of metallic elements.

An evaluation of the occurrence and trends in 137Cs and 40K radioactivity in King Bolete Boletus edulis mushrooms in Poland during 1995-2019

B. edulis, collected from 33 forested or woodland sites across Poland over 25 years since 1995, were analysed for radiocaesium. The results (137Cs activity range: 25 to 10,000 Bq kg-1 dry weight) provide a good indication of artificial radioactivity in this food material. The relatively higher levels detected in the earlier years, mostly in easterly location, is consistent with depositions from the projected Chernobyl incident (1986) fallout plumes. Nevertheless, the 137Cs concentrations during 1995-2010 were, on average, higher than those reported by other studies for Polish B. edulis over the period 1986-1994. The data concurs with the general hypothesis and observations that deposited 137Cs permeates slowly over time to deeper soil horizons which host the mycelial networks. This delay in availability shows that (apart from hotspots) higher contamination of fruiting bodies occurred around 10 to 20 years after the incident. Local consumers and recreational mushroomers were undoubtedly exposed, although reported 137Cs concentrations suggest that serious breaches of regulated levels were uncommon.

137Cs, 40K, and K in raw and stir-fried mushrooms from the Boletaceae family from the Midu region in Yunnan, Southwest China

The parallel batches of the same species and geographical origin mushrooms both raw and stir-fried were investigated to get an insight into the content and intake of ¹³⁷Cs, ⁴⁰K, and K from mushroom meals. The Boletaceae family species (Baorangia bicolor, Boletus bainiugan, Butyriboletus roseoflavus, Retiboletus griseus, Rugiboletus extremiorientalis, and Sutorius magnificus) were collected from the Midu County (Dali Bai Autonomous Prefecture) in 2018. The activity concentrations of ¹³⁷Cs in the caps of dried raw mushrooms were in the range 14 ± 1 Bq kg^-1 dry biomass (db) (R. griseus) to 34 ± 2 Bq kg^-1 db (R. extremiorientalis), and in stems from 16 ± 1 Bq kg^-1 db (B. bicolor and B. bainiugan) to 23 ± 1 Bq kg^-1 db (R. extremiorientalis). The mean activity concentration in the whole fruiting bodies in all six species was 18 ± 4 Bq kg^-1 db. The activity concentrations of ¹³⁷Cs were roughly the same in both dehydrated materials, stir-fried, and raw mushrooms, while the contents of ⁴⁰K and stable K were around 2- to 3-fold smaller in stir-fried than raw product. The raw and stir-fried mushrooms on a whole (wet) weight basis showed activity concentrations of ¹³⁷Cs in the range from 1.2 to 3.2 Bq kg^-1 ww (mean 1.9 ± 0.6 Bq kg^-1 ww) and 6.0 to 9.4 Bq kg^-1 ww (mean 7.0 ± 1.2 Bq kg^-1 ww), respectively. Evidently, when expressed on a whole (wet) weight basis, the cooked mushrooms showed on average around 3.5-fold greater activity concentration of ¹³⁷Cs when compared with raw mushrooms. The ¹³⁷Cs, ⁴⁰K, and total K enrichment in stir-frying (in a whole (wet) weight basis for the meal), confronted with the results for dehydrated raw and fried mushrooms, show the direct correlation with loss of mass (largely moisture) during the cooking procedure but not much of ¹³⁷Cs and ⁴⁰K. Edible wild mushrooms from Yunnan were little contaminated with radiocaesium. As assessed, the mean radioactivity dose from natural ⁴⁰K in around 9.3-fold exceeded the dose obtained for artificial ¹³⁷Cs from stir-fried mushroom meals, which both were very low doses.

Elution of Radioactive Cesium from Tofu by Water Soaking

Elution of cesium-137 (¹³⁷Cs) from tofu into water was investigated to know the behavior of ¹³⁷Cs during preservation and cooking. The food processing retention factor (Fr) reached 0.55 when tofu was soaked in water at a ratio of 1:2 w/w for 24 h at 4°C. Doubling the amount of water did not further significantly decrease Fr. When tofu was held in water at a ration of 1:2 w/w at a temperature of 80℃ for 50 min, Fr was 0.72. Increasing the amount of water to 10 times the tofu weight did not further reduce Fr significantly. Cesium-137 is mostly bound to tofu and does not freely diffuse into water. Tofu was then soaked in water at a ratio of 1:2 w/w at 4℃ for 24 h, placed in new water at a ratio of 1:2 w/w, and held at 80℃ for 50 min, resulting in an Fr 0.33. This value is close to an estimated Fr calculated by multiplying the Fr of 0.55 from soaking at 4°C by the Fr of 0.72 from the hot water treatment. The calculated Fr from soybeans sequentially processing into tofu, soaking tofu at 4°C for 24 h and in hot water at 80°C for 50 min was about 0.1, indicating 90% removal of ¹³⁷Cs. Degree of decrease in ¹³⁷Cs during preservation and cooking of tofu demonstrated in this study will be useful for exposure assessment of ¹³⁷Cs through oral intake of contaminated soybeans after processing and cooking.

Artificial (137Cs) and natural (40K) radioactivity and total potassium in medicinal fungi from Yunnan in China

Evaluated has been radioactive contamination with ¹³⁷Cs in parallel to occurrence of ⁴⁰K and total K in 31 species of medicinal mushrooms from Yunnan, China. We chose species that were not previously studied. The activity concentrations of ¹³⁷Cs in the medicinal fungi in this study were low. The maximum values were 54 ± 4 Bq kg^-1 dry biomass (db) in caps and 48 ± 5 Bq kg^-1 db in stipes of saprotrophic fungus Gerronema xanthophyllum from the family of Tricholomataceae. Mushrooms with relatively higher activity concentrations of ⁴⁰K were among the non-polypore species but certain species from the genus Ganoderma such as G. applanatum, G. capense, G. philippii and G. sinense showed ⁴⁰K in the higher range of 900 ± 240 to 1400 ± 340 Bq kg^-1 db. The concentrations of total K in the fungal materials in this study were in the range from 2.9 ± 6.5 g kg^-1 db in Fomes rufolaccatus to 110 ± 6 g kg^-1 db in G. xanthophyllum. The species studied, which represented both some popular wood-decaying polypore fungi but also terrestrial forms from the herbal medicine of China, can be considered as little contaminated with ¹³⁷Cs and potentially good source of leachable K in extract and decoction or as a powdered form in capsules.

Reduction in the Radiocesium in Meats of the Sika Deer and Wild Boar by Cooking

ABSTRACT

The behavior of radiocesium in wild animal meats upon cooking was investigated. The ratio of the concentration change (processing factor, Pf), remaining ratio (food processing retention factor, Fr), and removal ratio of radiocesium in the meats by grilling, boiling, and steaming were determined. Differences in cooking methods, rather than differences in meat parts or animal species, clearly influenced the Pf, Fr, and removal ratios. The mean Fr values were 0.9 (range, 0.7 to 1.0) for grilling, 0.6 (range, 0.4 to 0.7) for boiling, and 0.5 (range, 0.4 to 0.7) for steaming. The removal effect of grilling (11%) was lower than that of boiling (41%) or steaming (47%). The mean value of Pf was 1.2 (range, 1.1 to 1.6) for grilling, 0.8 (range, 0.6 to 0.9) for boiling, and 0.8 (range, 0.7 to 1.0) for steaming. The radiocesium concentration in the meats increased only upon grilling, but not by boiling or steaming. This difference is due to the lower removal effect of grilling than that of boiling and steaming. Therefore, boiling and steaming were more effective than grilling for removing radiocesium and reducing its concentration in wild animal meats. Furthermore, the ratio of water content fluctuations due to boiling was negatively correlated with Pf and Fr. It was evident that greater reductions in water content resulted in lower concentrations and improved radiocesium removal in the meats. These results suggest that some of the radiocesium naturally present in the meats is soluble in water and that the radiocesium dissolved in water can be removed from the meat with the release of water from the tissue.

HIGHLIGHTS

Uranium, Thorium, Potassium, and Cesium Radionuclides Concentrations in Desert Truffles from the Governorate of Samawah in Southern Iraq

Studies have been conducted in some southern Iraqi governorates to measure the radioactive contamination in the soil and have revealed that these areas are contaminated with radioactive materials. In these test sites, where many military operations have been conducted and that may have been affected by the Chernobyl accident, pollution and its impact on the truffle crop have been examined. Truffles are fungi that grow in the ground and can be contaminated by radiation from polluted soil. Uranium, thorium, potassium, and cesium activities were analyzed in truffles collected from the desert of Samawah governorate in the southern part of Iraq, and the results were compared with global values. The radionuclide activities were measured with a high-purity germanium detector. The average activities of ²³⁸U, ²³²Th, ⁴⁰K, and ¹³⁷Cs were 3.9500, 2.5300, 260.36, and 1.7800 Bq kg^-1 dry biomass, respectively. These results indicate that radionuclide activities are low and that desert truffles are suitable for human consumption.

Distribution of Radioactive Cesium during Milling and Cooking of Contaminated Buckwheat

To clarify the behavior of radioactive cesium (Cs) in buckwheat grains during milling and cooking processes, parameters such as processing factor (Pf) and food processing retention factor (Fr) were evaluated in two lots of buckwheat grains, R1 and R2, with different concentrations of radioactive Cs. Three milling fractions, the husk, bran, and flour fractions, were obtained using a mill and electric sieve. The radioactive Cs (¹³⁴Cs + ¹³⁷Cs) concentrations in husk and bran were higher than that in grain, whereas the concentration in flour was lower than that in grain. Pf values for the flours of R1 and R2 were 0.60 and 0.80, respectively. Fr values for the flours of R1 and R2 were 0.28 and 0.53, respectively. Raw buckwheat noodles (soba) were prepared using a mixture of buckwheat flour and wheat flour according to the typical recipe and were cooked with boiling water for 0.5, 1, and 2 min, followed by rinsing with water. Pf values for the soba boiled for 2 min (optimal for eating) made with R1 and R2 were 0.34 and 0.40, respectively. Fr values for these R1 and R2 samples were 0.55 and 0.66, respectively. Pf and Fr values for soba boiled for different times for both R1 and R2 were less than 0.6 and 0.8, respectively. Thus, buckwheat flour and its product, soba, cooked by boiling, are considered acceptable for human consumption according to the standard limit for radioactive Cs in buckwheat grains.

Activities concentration of radiocesium in wild mushroom collected in Ukraine 30 years after the Chernobyl power plant accident

Mushrooms are recognized as one of the main contributors to internal radiation exposure from the activity concentration of radiocesium released by the accident at the Chernobyl nuclear power plant (CNNP). We evaluated the activity concentrations of the artificial radionuclides (radiocesium) in wild mushrooms collected in 2015 from Korosten and Lugine, Zhitomir region, Ukraine, located 120 km away from the CNPP. Cesium-137 was detected in 110 of 127 mushroom samples (86.6%). Based on the average mushroom consumption (5 kg per year), we calculated committed effective doses ranging from 0.001–0.12 mSv. Cesium-137 remains in the wild mushrooms even 30 years after the accident, but the committed effective doses are limited by the amount of contaminated mushrooms consumed. However, evaluation of internal radiation exposure and assessment of environmental radioactivity in the surrounding area affected by the nuclear accident are still necessary in order to relieve anxiety about internal radiation exposure, as long as the possibility of consumption of contaminated mushrooms remains.

Artificial 137Cs and natural 40K in mushrooms from the subalpine region of the Minya Konka summit and Yunnan Province in China

A study on ¹³⁷Cs pollution and activity concentrations of ⁴⁰K in mushrooms of the genera Cortinarius, Leccinum, Russula, Tricholoma, Tylopilus, and Xerocomus from two neighboring regions in southwest China in 2010-2013 revealed different patterns of pollution with ¹³⁷Cs, which seemed to be highly dependent on climate conditions. Tricholoma matsutake was collected in Yunnan before and after the Fukushima Dai-ichi nuclear accident and showed similar contamination with ¹³⁷Cs. Mushrooms from the elevation of 2800-3480 m above sea level on the east slope of Minya Konka and forest topsoil showed higher contamination with ¹³⁷Cs than mushrooms from the highlands of Yunnan. In detail, the activity concentration of ¹³⁷Cs in caps of mushrooms from Minya Konka were in the range 62 ± 6-280 ± 150 Bq kg^-1 dry biomass and from Yunnan at < 4.4-83 ± 3 Bq kg^-1 dry biomass. The climate in the region of the Minya Konka is much colder than in Yunnan, which seems to favor deposition of ¹³⁷Cs at higher altitudes from global atmospheric circulation. The activity concentration of ⁴⁰K in mushrooms and soils highly exceeded that of ¹³⁷Cs. The assessed annual effective doses for ¹³⁷Cs in 1 kg of consumed mushrooms of the genera Leccinum and Xerocomus in Yunnan were low, i.e., in the range < 0.0043-0.049 ± 0.004 μSv, while those for ⁴⁰K were 0.26 ± 0.02-0.81 ± 0.09 μSv.

Radioactive caesium (134Cs and 137Cs) in mushrooms of the genus Boletus from the Reggio Emilia in Italy and Pomerania in Poland

Activity concentrations of ¹³⁴Cs and ¹³⁷Cs were determined in mushrooms of the Boletus species B. aereus, B. reticulatus, B. appendiculatus, B. calopus, B. edulis, B. erythropus, B. fechtneri, B. pinophilus, B. pseudoregius, B. rhodopurpureus, B. rhodoxanthus collected in the Reggio Emilia, Italy, in 1993 and 1994 and in B. edulis collected in Pomerania in northern Poland in the period from 1995-2015. Boletus edulis from the Reggio Emilia showed presence of ¹³⁷Cs at 330 ± 220 Bq kg^-1 dry biomass in 1993 and at 370 ± 180 Bq kg^-1 dry biomass in 1994. In B. edulis sampled in the Reggio Emilia in 1993 and 1994, the pre-Chernobyl ¹³⁷Cs from global fallout amounted to 39-46 % of the total activity concentrations of isotope ¹³⁷Cs. B. edulis from Pomerania contained ¹³⁷Cs in caps at 270 ± 15 Bq kg^-1 dry biomass in 1995, and in whole fruiting bodies it was found to be 470 ± 9 Bq kg^-1 dry biomass in 2015. The activity concentrations of ¹³⁷Cs determined in fruiting bodies of B. edulis from Pomerania fluctuated but persisted over the period from 1995 to 2015, while the maximum activity concentrations were well below the tolerance limit of 600 Bq kg^-1 fresh product.

Pickling of chanterelle Cantharellus cibarius mushrooms highly reduce cadmium contamination

Mushrooms are considered as potential bio-remediation agents in soil polluted with heavy metals, while many species which efficiently accumulate them in flesh are edible. Question is if there is any possible culinary use of edible mushrooms with high heavy metal contents? This study aimed to investigate and discuss a fate of cadmium (Cd) in common household-treated fruitbodies of common chanterelle Cantharellus cibarius. The samples of Cantharellus cibarius Fr. were collected from five spatially distanced sites in Poland in 2011-2012. We examined from 267 to 358 fruiting bodies per collection, and in total 1565 fruiting bodies were used. Cadmium in fungal materials from all treatments and processes (mushrooms dried, deep frozen, blanched and pickled) was determined using validated methods by inductively coupled plasma mass spectrometry with dynamic reaction cell. Blanching of fresh chanterelles caused decrease of Cd by around 11 ± 7 to 36 ± 7%, while blanching of deep-frozen mushrooms by around 40 ± 6%. A rate of Cd decrease in chanterelles was similar when the fruiting bodies were blanched for 5 or 15 min and when used was potable or deionized water. Pickling of blanched chanterelles with a diluted vinegar marinade had a pronounced effect on further removal of Cd. Blanched chanterelles when pickled lost an extra 37-71% of Cd. Total leaching rate of Cd from fresh or deep-frozen fruitbodies of chanterelle when blanched and further pickled was between 77 ± 7 and 91 ± 4%. Blanching and pickling highly decreased content of Cd in C. cibarius.

Mushrooms: from nutrition to mycoremediation

Mushrooms are well known as important food items. The uses of mushrooms in the cuisine are manifolds and are being utilized for thousands of years in both Oriental and Occidental cultures. Medicinal properties of mushrooms show an immense potential as drugs for the treatment of various diseases as they are rich in a great variety of phytochemicals. In this review, we attempted to encompass the recent knowledge and scientific advancement about mushrooms and their utilization as food or curative properties, along with their natural ability to accumulate (heavy) metals/radionuclides, which leads to an important aspect of bioremediation. However, accumulation of heavy metals and radionuclides from natural or anthropogenic sources also involves potential nutritional hazards upon consumption. These hazards have been pointed out in this review incorporating a selection of the most recently published literature.

Analysis of some metallic elements and metalloids composition and relationships in parasol mushroom Macrolepiota procera

The aim of the study was to characterise the multi-elemental composition and associations between a group of 32 elements and 16 rare earth elements collected by mycelium from growing substrates and accumulated in fruiting bodies of Macrolepiota procera from 16 sites from the lowland areas of Poland. The elements were quantified by inductively coupled plasma quadrupole mass spectrometry using validated method. The correlation matrix obtained from a possible 48 × 16 data matrix has been used to examine if any association exits between 48 elements in mushrooms foraged from 16 sampling localizations by multivariate approach using principal component (PC) analysis. The model could explain up to 93% variability by eight factors for which an eigenvalue value was ≥1. Absolute values of the correlation coefficient were above 0.72 (significance at p < 0.05) for 43 elements. From a point of view by consumer, the absolute content of Cd, Hg, Pb in caps of M. procera collected from background (unpolluted) areas could be considered elevated while sporadic/occasional ingestion of this mushroom is considered safe. The multivariate functional analysis revealed on associated accumulation of many elements in this mushroom. M. procera seem to possess some features of a bio-indicative species for anthropogenic Pb but also for some geogenic metals.

Radioactive artificial 137Cs and natural 40K activity in 21 edible mushrooms of the genus Boletus species from SW China

This study, for the first time, presents the results of activity concentration determinations for ¹³⁷Cs and ⁴⁰K in a high number (21 species, 87 composite samples, and 807 fruiting bodies) of mushrooms of the genus Boletus from across Yunnan in 2011-2014 and Sichuan (Boletus tomentipes) using high-resolution high-purity germanium detector. Activity concentrations of ¹³⁷Cs demonstrated some variability and range from <4.4 to 83 ± 3 Bq kg^-1 dry biomass in caps and from <3.8 to 37 ± 3 Bq kg^-1 dry biomass in stipes, and of ⁴⁰K, respectively, from 420 ± 41 to 1300 ± 110 and from 520 ± 61 to 1300 ± 140 Bq kg^-1 dry biomass. No significant variations were observed regarding ¹³⁷Cs and ⁴⁰K activity concentrations among the same Boletus species from different sampling sites. No activity concentrations from ¹³⁴Cs were detected in any mushrooms. Internal dose rates estimated were from intake of 1 kg of mushrooms per annum for ¹³⁷Cs range for species and regions from around <0.0031 to 0.047 ± 0.003 μSv, while those for ⁴⁰K were from around 0.22 ± 0.04 to 1.2 ± 0.1 μSv. The overall intake of ¹³⁷Cs was low since low contamination was found in Boletus species.