Radionuclides in Mushrooms and Soil-to-mushroom Transfer Factors in Partial Areas of China National Institute for Radiological Protection Fei Tuo

Transcription

1 Radionuclides in Mushrooms and Soil-to-mushroom Transfer Factors in Partial Areas of China National Institute for Radiological Protection Fei Tuo 4 Oct Teddington tuofei@nirp.cn; Tel:

2 Contents 1. Introduction and Objectives 2. Material and Methods 3. Results and Discussion

3 1.Introduction and Objectives Introductio n Most radionuclides can be bioaccumulated by mushrooms and 137 Cs in wild mushroom species can be detected consistently. It often considered as excellent bioindicators for evaluation of environmental pollution. Mushrooms are also consumed by people and directly eaten by animals. Regular consumption of these mushrooms or animals may pose a human health concern. Therefor, knowing the related information about radioactivity concentration of mushrooms in China is significant to public health.

4 2017/10/19 4

5 2017/10/19 5

6 1.Introduction and Objectives Evaluating 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K activity concentrations in mushrooms and Objectives determining their transfer. The present study is the first radioactive content and transfer factor analysis of Chinese originated wild mushrooms.

7 2.Material and Methods 2.1 Mushroom sampling and sample pre-treatment A total of 64 wild mushroom samples were collected from following area of China : Geographic al position of sampling site 59 samples 3 samples 2 samples

8 Picture of some mushrooms 2017/10/19 8

9 2.Material and Methods 2.1 Mushroom sample pre-treatment Drying Grinding into powder Homogenizing in a domestic blender Placing in a polyethylene bottle Sealing the bottle with adhesive tape Storing the bottle for approximately four weeks

10 2.Material and Methods 2.2 Soil sampling and sample pre-treatment Collecting surface soil samples and Recording latitude and longitude Identifying soil type and removing stones and pebbles Drying Grinding and sieving Bottling and sealing Set aside for at least four weeks

11 2.Material and Methods 2.3 Gamma spectrometry Instruments and software: Activities of gamma emitters in mushrooms samples: GR6019(CANBERRA) Genie 2000 LabSOCS (efficiency calibration tool ) 1.71 kev 60 Co 53% efficiency Activities of gamma emitters in soil samples: GEM50195(ORTEC ) GammaVision 1.9 kev 60 Co Efficiency of 51%

12 2.Material and Methods 2.4 Transfer factor determination AM(mushroom):activity concentration detected in the fruiting bodies, AS(surface soil):activity concentration detected in the corresponding surface soil. Quality control: Intercomparison of γ-spectrometry measurement and analysis,jcac,nim,nirp Validity of the radiometric methods The result was assigned acceptable score if: En 1,

13 Validity of the radiometric methods 2017/10/19 13

14 3.Results and Discussion 3.1 Radionuclides in mushroom samples The activity concentrations of radionuclides in 64 mushroom samples are given in the following table (Bq/kg -1, dry weight): Species Latin name Boletus aereus.fr.:bull Boletus brunneissimus W.F.Chin Number of samples Edible or not * Originated 238 U 226 Ra 228 Ra 137 Cs Median(Range) Median(Range) Median(Range) Median(Range) Median(Range) 8 E Yunnan 2.06( )0.24( )0.81( ) 1.66( ) 6 E Yunnan Boletus edulis bull 6 E Yunnan Tylopllus bolloul(peck)singer 7 E Yunnan Lentinu edodes 11 E Yunnan Gomphus floccosus(schw.) Singer Termitomyces alluminosus (Berk.) 3 E Yunnan 3.315( ) 1.19( ) 2.26( ) 1.63( ) 3.68( ) 0.75( ) 0.35( ) 2.255( ) 1.72( ) 0.55( ) 0.98( ) 0.29( ) 3.65( ) 3 E Yunnan 3.44( ) 0.37( ) Boletus sp. 3 NE Yunnan Tylopilus felleus 3 NE Yunnan 0.38( ) 5.48( ) 0.59( ) 0.835( ) 40 K 716( ) 762( ) 0.7( )758( ) 2.91( ) 8.42( ) 212( ) 5.87( ) 583( ) 629 ( ) 975( ) 607( ) 4.01( ( ( ) 1.24( ( ) 6.09) 1.43) 1.27) 2.58( ( ( ( ( )

15 3.Results and Discussion continue Species Latin name Number of samples Edible or not * Originated 238 U 226 Ra 228 Ra 137 Cs 40 K Cantharellus cibarius Fr. Hygrophorus russula(fr.)qael Boletus obscureumbrinu s Hongo lycopersicon lycopersicum Lactarius volemus(fr.:fr.)f r Lactarius hatsudake Agricus blazei murrill Collybia albuminosa Agrocybe cylindracea (DC.ex Fr.)R.Maire 1 E Yunnan E Yunnan E Yunnan E Yunnan E Yunnan E Yunnan E Yunnan E Yunnan E Yunnan

16 3.Results and Discussion continue Species Latin name Number of samples Edible or not * Originated 238 U 226 Ra 228 Ra 137 Cs 40 K Flammulina velutipes (curt. exfr.)sing. Pleurotus djamor(fr.) Boedjin Lyophyllum ulmarium(bul l.exfr.)fuhn Tricholoma mongolicum Imai Armillaria solidipes 1 E Fujian E Fujian E 1 E 1 E Heilongjia ng Heilongjia ng Heilongjia ng Median All species Range All species

17 3.Results and Discussion The activity concentrations of 238 U, 226 Ra, 228 Ra, 137 Cs and 40 K in mushrooms varied from Bq/kg 1, 0.05 to 7.45 Bq/kg 1, 0.14 to 13.9 Bq/kg 1, MDC(<0.01) to 339 Bq/kg 1, 396 to 1877 Bq/kg 1, respectively and the medians activity concentrations of which were 2.32Bq/kg 1, 0.39 Bq/kg 1, 1.12Bq/kg 1, 2.37Bq/kg 1, 760Bq/kg 1, respectively. The vast majority of the mushroom samples showed the presence of 137 Cs, mushroom named Gomphus floccosus (Schw.) Singer obtained the maximum value(339 Bq/kg 1 dry weight or 40 Bq/kg 1 fresh weight) for 137 Cs, which was lower than the allowed level in China(210 Bq kg 1,fresh weight) and may be used as a potential good bio-indicator of the 137 Cs in the ecosystem.

18 Spectrums of Gomphus floccosus Singer & background 137 Cs Daughter of 226 Ra 137 Cs Gomphus floccosus Singer (Net area=22500,lt=86400s) Background (Net area=0,lt=133807s) 2017/10/19 18

19 3.Results and Discussion A comparison of reported activity concentrations ranges in mushrooms from the literature are presented in the following table(bq/kg -1, dry weight): Country Norway, Øvre Dividalen Brazil, Sao Paulo Spain, Munoveros andbazagona Finland, Parkano and Inari New Zealand, Christchurch and Wellington Number of samples (or species) 238 U 226 Ra 228 Ra 137 Cs 40 K 4 * * * * Source of information Justin P. G., Anna N., Geir R., De Castro L.P., Maihara V.A., Silva P.S.C., et al, * * * Baeza A.,Guillen J., * * * 200~19900 * Jukka L., Kaisa V., Anumaija L., * * * * * S., Hermanspahn N., Glover C.N., Pearson A.J., Gaw Spain * * * ,700,000 Finland, Northern Finland Guillén J., Baeza A., * * * * Koivurova M., Leppänen A., Kallio A., Netherlands 7 * * * * Brandhoff P.N., Van Bourgondiën M.J., Onstenk C.G.M., et al, 2016.

20 3.Results and Discussion The activity concentration of natural radionuclides( 238 U 226 Ra 228 Ra) fell in the range of typical world-wide concentration values. Except for G. floccosus, the concentration of 137 Cs for most of the species were in agreement with the global fallout levels reported for Brazil, Finland and Netherlands, while lower than those collected in Øvre Dividalen, Norway, Parkano and Inari. The reason of which may be the differences between species and the impect of Chernobyl nuclear accident.

21 3.Results and Discussion 3.2 Radionuclide concentrations in soil samples Radionuclide concentrations in 15 soil samples are showed in the following table(bq/kg -1,dry weight): Soil samples Sample code 238 U * 226 Ra * 228 Ra * 137 Cs * 40 K * Soil of Boletus edulis bull A1 28.3± ± ± ± ±14 A2 52.4± ± ± ± ±19 A3 27.9± ± ± ± ±13 Soil of Tylopllus bolloul(peck)sin ger B1 34.8± ± ± ± ±19 B2 35.4± ± ± ± ±19 B3 55.9± ± ± ± ±19 Soil of Boletus brunneissimus W.F.Chin C1 38.6± ± ± ± ±18 C2 51.5± ± ± ± ±20 C3 21.7± ± ± ± ±10

22 3.Results and Discussion continued Soil samples Sample code 238 U * 226 Ra * 228 Ra * 137 Cs * 40 K * Soil of Boletus sp. D1 45.7± ± ± ± ±23 D2 44.2± ± ± ± ±20 Soil of Tylopilus felleus(bull.:fr.) karst D3 42.7± ± ± ± ±20 E1 34.6± ± ± ± ±20 E2 34.3± ± ± ± ±19 E3 49.1± ± ± ± ±21 China ((Zhang et al., 1988)) Yunnan Province((Zhang et al., 1988)) World wild values((unscear, 2000) Present work (Median) Present work (Range)

23 3.Results and Discussion Activity concentrations of radionuclides in top soil samples fell in the range of typical world-wide concentration values. All samples showed the presence of 137 Cs. The studied area did not show any large discrepancy among each sampling point compared with previous investigation data (Zhang, et al.1988) nor did we find any obvious hotspots of 137 Cs.

24 3.Results and Discussion 3.3 Soil to mushroom Transfer Factors (TF) The soil to mushroom TF values for different species of mushrooms collected in Nanhua, Yunnan ecosystems were listed in the following table: Species * 238 U( 10-2 ) 226 Ra( 10-2 ) 228 Ra( 10-2 ) 137 Cs( 10-1 ) 40 K Boletus edulis bull (E) Tylopllus bolloul(peck)sin ger (E) Boletus brunneissimus W.F.Chin (E) Boletus sp. (NE) Tylopilus felleus (Bull.:Fr.) karst (NE)

25 3.Results and Discussion The TF values for 238 U, 226 Ra, 228 Ra considering all the five species was in the order of 10-2, the medians of the TF values was , , , respectively. The TF values for 137 Cs in individual mushroom of investigated species were in the order of 10-1, the median of which was 0.40 and the range was , which were in agreement with previously reported transfer values in Northern Norway. The literature data available for soil mushroom TF of 238 U, 226 Ra, 228 Ra is practically inexistent because of it's very large range( ).

26 Conclusions The results from this work are meaningful for assessing the human radiation exposure. It can provide a reference for the study of the geological setting of Southwest China and of international. We need cooperation and wish get more technical advise

27 Thank you! 谢谢!