Evaluations of environmental hazard parameters of natural and some artificial radionuclides in river water and sediments

Accepted Manuscript Evaluations of environmental hazard parameters of natural and some artificial radionuclides in river water and sediments

Özlem Selçuk Zorer PII: DOI: Reference:

S0026-265X(18)31229-3 https://doi.org/10.1016/j.microc.2018.11.035 MICROC 3480

To appear in:

Microchemical Journal

Received date: Revised date: Accepted date:

27 September 2018 19 November 2018 19 November 2018

Please cite this article as: Özlem Selçuk Zorer , Evaluations of environmental hazard parameters of natural and some artificial radionuclides in river water and sediments. Microc (2018), https://doi.org/10.1016/j.microc.2018.11.035

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Evaluations of Environmental Hazard Parameters of Natural and Some Artificial Radionuclides in River Water and Sediments

Özlem Selçuk Zorer

Turkey

SC RI PT

Van Yuzuncu Yil University, Faculty of Science, Department of Chemistry, 65080, Van,

E-mail: [email protected] Abstract

137

NU

In order to evaluate the radiological baseline in the Lake Van basin, 238U, 232Th, 226Ra, Cs and 40K activity concentrations and gross radioactivity were determined in twelve river

MA

water and sediment samples. To determine radionuclide activities and gross radioactivity, a gamma ray spectrometer with HPGe detector and a gross-alpha/beta-counting system low

ED

background multi-detector were used, respectively. Therefore, based on the measured activity concentrations, parameters of radiological hazards such as radium equivalent activity, outdoor

PT

absorbed dose rate, annual effective dose, and internal and external hazard indices were

CE

calculated. Req, Hex and Hin values in samples were generally lower than worldwide average

AC

values; while Dout and AED values were higher than worldwide average values in general.

Keywords: Natural radionuclides; gross radioactivity; sediment; water; hazard parameters

1. Introduction

Naturally-occurring radioisotopes in the environment are connected with 232

Th, and

40

226

Ra (238U),

K radioisotopes in rocks, sand, soils, and sediments. Artificial radionuclides in

1

ACCEPTED MANUSCRIPT the environment arise from anthropogenic sources, such as weapon tests, nuclear medicine, nuclear accidents, and nuclear fuel cycles. Radioactivity in the environment and external exposure due to gamma radiation occurs at different levels in nature and it varies geographically due to geological changes in each region of the world [1]. 226Ra (238U), and

40

232

Th,

K distributions in sands are associated with radionuclide availability in bedrock,

SC RI PT

together with the chemical and mechanical processes through which the sands are concentrated. The specific terrestrial background radiation levels are connected with the types of rocks from which the sediments originate. Igneous rocks containing dark-coloured heavy minerals usually have higher radiation, whereas lower level radiation comes from sedimentary

NU

rocks. The ratio of Th to U in bedrock is considerably lower than in soils due to the accumulation and migration capabilities of Th and U.

MA

Radionuclides with half-lives long enough to be compared with the earth's crust are called primordial radionuclides. Radioactivity in the surface layers of the soil originates in the 238

U, 232Th, 40K and 87Rb. The anthropogenic

ED

decay of primordial radionuclides such as

radionuclides such as 137Cs and 90Sr are also available in considerable amounts in the soil due

PT

to nuclear weapon tests and nuclear accidents. The terrestrial gamma radiation levels are

CE

highly affected by radioisotopes that are present in soil. The purposes of the present research were to investigate the distribution of

AC

radionuclide activity in the Lake Van Basin and to compute radiation hazard parameters due to the presence of 238U, 232Th and 40K in samples. It is essential to establish both radiometric and radiological baseline data, which do not exist yet. Therefore, radionuclide activity and gross-α/β radioactivity concentrations were measured by using a gamma ray spectrometer with HPGe detector and gas-flow proportional counter, respectively.

2. Results and Discussion

2

ACCEPTED MANUSCRIPT

2.1. Radioactivity analysis

The activity concentrations of detected radionuclides, 238U, 232Th, 40K, 137Cs, and gross radioactivity in water samples for spring and summer seasons are reported in Table 1. The

238

U, 2.9-12.7 Bq/L for

232

Th, 6.4-28.18 Bq/L for

SC RI PT

activity concentrations in the water samples were measured at a range of 1.67-8.91 Bq/L for 40

137

K and 0.27-0.52 Bq/L for

Cs in the

spring season. In the summer season, the activity concentrations of radionuclides varied: for U between 2.09 and 7.36 Bq/L; for

12.75 and 35.95 Bq/L; and for

232

Th between 0.71 and 11.95 Bq/L; for

137

40

K between

Cs between 0.29 and 0.59 Bq/L. The mean activities of

NU

238

Bq/L for 40K and 0.36 Bq/L for 137Cs.

238

U, 5.61 Bq/L for

232

Th, 21.6

MA

radionuclides in both seasons were found as 3.97 Bq/L for

Radionuclides in structure of soils and rocks arrive to surface waters with rain and

ED

snow waters via precipitation and flooding. Radionuclides mixed to groundwater by filtering from soil have contributed to the increased radioactivity concentration in water samples. Due

PT

to the high rainfall in the spring season, radionuclides are more likely to reach the surface

CE

water through filtration and leaching. It can be said that decreasing rainfall in summer season affects radionuclides and their activities reaching surface waters.

AC

The distribution of radionuclide activities in water samples are illustrated in Figure S1. The radionuclide activity concentration values varied according to sampling points, because the bed of each river passes through regions with different geological structure and may have different chemical and mineralogical composition. Limit values proposed by the EPA for radioactivity concentrations in groundwater are 0.2 Bq/L (5 pCi/L) for

226

Ra (with

228

Ra), 1.1 Bq/L (30 pCi/L) for

234

U (with

238

U) and 0.6

Bq/L (15 pCi/L) for gross alpha activity (without radon and uranium) [2]. According to these

3

ACCEPTED MANUSCRIPT limit values; while the uranium activities in the river water samples for both seasons are found to be high, the gross-α activity concentrations are quite low. However, the permissible limits 232

Th, 235U and 226Ra in drinking water according to the World Health Organization are

1 Bq/L while the limit for 238U and consideration, the

238

U and

137

137

Cs is 10 Bq/L [3]. When these limits are taken into

Cs activity concentrations in the water samples are below the

limit values for both seasons, while the

232

Th concentrations are above the values. At the

SC RI PT

for

same time, recommended values for drinking waters are 0.5 Bq/L for gross-α radioactivity and 1 Bq/L for gross-β radioactivity [3]. In all samples, gross-α/β activity concentrations measured are below the limit values.

Ra, 40K and 137Cs) and gross radioactivity in the sediment samples for spring and summer

seasons. The

226

Ra activity concentrations ranged between 23.46 and 85.29 Bq/kg and mean

concentration of

226

radioactivities of

232

MA

226

NU

Table 2 demonstrates the natural radionuclide radioactivity concentrations (232Th,

Ra was calculated as 47.48 Bq/kg. The maximum, minimum and mean

ED

Th were 118.07, 20.64 and 57.87 Bq/kg, respectively. The

137

Cs activity

concentrations were measured as 0.3 Bq/kg for minimum, 17.92 Bq/kg for maximum and 4.37

PT

Bq/kg for mean. The lowest and highest activity concentrations of

40

K were found as 400.64

CE

Bq/kg in S3 sample in summer and 1722.59 Bq/kg in S9 sample in spring, while the mean concentration was found as 1021.43 Bq/kg. The gross-α and gross-β activity concentrations

AC

ranged from 0.22-6.44 Bq/kg and 0.7-8.22 Bq/kg, respectively. Radioactive elements are concentrated mostly in the surface layers of soil as their migration downwards is limited and depends on the many chemical and physical conditions of the soil system [4, 5]. The leached radionuclides from igneous rocks, soils and agricultural areas are transported to under terrains and into rivers by rainwater and erosion. However, agricultural fertilizers products contain various trace elements such as uranium and thorium decay series members [6]. Due to temperature increase effect, chemical structure of soil and

4

ACCEPTED MANUSCRIPT fertilization activities, radioactivity in sediments is expected to be partly high in summer season. Worldwide average concentrations of

226

Ra,

232

Th and

40

K in soil are 35 Bq/kg, 30

Bq/kg and 400 Bq/kg, respectively. The population-weighted average concentrations of these radionuclides are 32 Bq/kg, 45 Bq/kg and 420 Bq/kg, respectively [7]. Compared to these 226

Ra activities of samples S3, S6 and S11 were determined to be lower than the

SC RI PT

limits, the

permissible population-weighted average values. In terms of

232

Th activities, S2, S3, S7, S11

and S12 samples have lower concentrations than both the permissible average and populationweighted average limit values. The

40

K radioactivity of S3 sample is lower than the

NU

worldwide population-weighted average limit, while it almost equals to the worldwide average limit.

MA

The locations of S4, S5, S8, S9 and S10 samples have volcanic rock structure. S4 and S5 samples were collected from rivers on the skirts of Mount Nemrut Volcano, while S8, S9

ED

and S10 samples were from rivers flowing in beds composed of volcanic rocks produced by Mount Süphan Volcano and the volcanic Tendürek Mountain. Since uranium and thorium can

PT

be concentrated in rocks by igneous and sedimentary processes [8], it is an expected result

CE

that natural radionuclide concentrations are high in these samples taken from rivers flowing in volcanic terrain. Based on the high natural radionuclide concentrations in these samples, the

AC

gross-α/β activities are also relatively high. In addition, the measurements showed that the higher than the other radionuclides. The

40

40

K activities in all samples were

K activity concentration is higher than the

concentration of 226Ra and 232Th, which is normally expected for soil. The excess of 40K in the study regions may be due to over-fertilization and geological differences. The relationships between radionuclides in sediments are illustrated in Figure S2. As seen in the figure, moderate positive correlations were observed between 226Ra and 232Th (Fig.

5

ACCEPTED MANUSCRIPT S2b) (R2=0.62) and between 226Ra and 40K (Fig. S2c) (R2=0.54), a weak positive correlation was observed between 226Ra and 137Cs (Fig. S2a) (R2=0.05), and strong positive correlation was observed between 232Th and 40K (Fig. S2d) (R2=0.90). In the literature, positive correlations between 232Th and 226Ra, while

232

Th and

40

232

Th and 40K,

226

Ra and 40K have been shown [9-11],

K have a weak positive correlation [12] and

Ra and 137Cs have a weak

SC RI PT

negative correlation [13].

226

The correlation of gross-α and gross-β in sediment samples is illustrated in Figure S3. The gross-β activity concentrations are higher than gross-α concentrations, but there is a positive correlation between both activity concentrations.

NU

The comparison of radionuclide activity concentrations in river water and sediment samples with reported values in other locations around the world are presented in Table 3. In

MA

the present study, the mean radioactivity values of

226

Ra,

232

Th and

are almost in accord with the other average values. The mean

40

238

K in sediment samples

U,

232

Th,

40

K and

137

Cs

ED

radioactivities in water samples are quite close to the radionuclide activities in many parts of

PT

the world.

CE

2.2. Radiation Hazard Parameters

AC

Radium equivalent activity (Raeq), outdoor absorbed gamma dose rate (Dout) and annual effective dose (AED), and external and internal hazard indices (Hex, Hin) calculated based on radionuclide activities in sediment samples are presented in Table 4. The values of Raeq for the sediment samples ranged from 92.8 to 386.8 Bq/kg in spring and from 91.3 to 321.0 Bq/kg in summer. The average Raeq value reported is 370 Bq/kg [7]. Except for S9 sample in spring, Raeq values in all sediment samples were determined to be within world standards.

6

ACCEPTED MANUSCRIPT The outdoor absorbed gamma dose rate (Dout) values were calculated in the range of 40.75-167.87 nGy/h for spring season and 40.15-139.55 nGy/h for summer season. The worldwide average and the population-weighted average values of Dout reported are 57 nGy/h and 59 nGy/h, respectively [7]. Except for three samples (S2, S3, and S7) in spring season and three samples (S3, S7 and S11) in summer season, Dout was found to be higher than the

SC RI PT

recommended world average values in all other samples.

The calculated annual effective dose (AED) ranged from 49.96 to 205.88 μSv/y with the mean value of 110.25 μSv/y for spring and ranged from 49.24 to 171.14 μSv/y with the mean value of 114.93 μSv/y for summer. As in the case of Dout values, all AED values are

NU

higher than the world average value of 70 μSv/y [1], except for three samples in both seasons. The minimum and maximum external hazard index (Hex) calculated depending upon

MA

radionuclide activities in sediment samples were 0.25 and 1.05 for spring season and 0.25 and 0.87 for summer season. The internal hazard index (Hin) ranged from 0.31 to 1.28 for spring

ED

and 0.31 to 1.06 for summer. While the internal and external hazard indices should not exceed 1, the Hex value in S9 sample for only the spring season and Hin values in S8, S9 and S10

PT

samples for both spring and summer seasons were higher than 1. When the internal hazard

CE

index is considered as the hazard for the respiratory organs due to radon and short-lived isotopes, there may be a health hazard in stations with Hin values greater than 1.

AC

Figure S4 shows the comparison of all radiation hazard parameters with the world averages. According to the figure, outdoor absorbed gamma dose rate (Dout) and annual effective dose (AED) values in sediment samples are higher than worldwide averages except for six samples.

3. Conclusions

7

ACCEPTED MANUSCRIPT The river sediment and water samples, collected from 12 points in both spring and summer seasons, were analysed for natural and anthropogenic radionuclides and gross radioactivity using HPGe detector and gas-flow proportional counter. In river water samples, the mean radioactivity concentrations of

238

U, 232Th, 40K and 137Cs in both seasons were 3.97

Bq/L, 5.61 Bq/L, 21.6 Bq/L, and 0.36 Bq/L, respectively. In river sediment samples, while S3

SC RI PT

sample had the lowest value for radionuclide activity concentrations, S8, S9 and S10 samples, especially, had the highest average values. As these samples were collected from rivers flowing in a volcanic field and the concentrations of radioactive elements in the volcanic rocks was higher, the radionuclide activities of these samples and their corresponding gross

NU

radioactivity were found to be higher. All of the results show that radioactivity concentrations were influenced by the geological structure and distribution.

MA

However, depending upon the measured activity concentrations, radium equivalent activity (Req), outdoor absorbed dose rate (Dout), annual effective dose (AED), and external

ED

and internal hazard indices (Hex, Hin) were calculated and the health risks were evaluated. When the calculated hazard parameter values are compared to the world averages, it can be

PT

said that the radioactivities in samples S8, S9 and S10 could constitute a radiation risk for the

CE

local population.

AC

Acknowledgements: The author thanks to the University of Van Yuzuncu Yil Scientific Research Projects Support Unit for their financial support (Project No. 2009-FED-B011).

References

8

ACCEPTED MANUSCRIPT [1] UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiation, Sources and Effects of Ionizing Radiation. Report to General Assembly, with Scientific Annexes United Nations. United Nations, New York, 2000. [2] EPA, Evaluation of Guidelines for Exposures to Technologically Enhanced Naturally Occurring Radioactive Materials, Committee on Evaluation of EPA Guidelines for

SC RI PT

Exposure to Naturally Occurring Radioactive Materials, National Research Council. National Academy Press, Washington DC, 1999.

[3] WHO, Guidelines for drinking-water quality: 4th edition, chapter 9: radiological aspects, World Health Organisation, Geneva, 2011.

NU

[4] K.H. Lieser,. Radionuclides in the Geosphere: Sources, mobility, reactions in natural waters and interactions with solids. Radiochim Acta, 70/71 (1995) 355–375.

241

MA

[5] K. Bunzl, W. Kracke, W. Schimmack, Vertical migration of

239+240

Plutonium,

Americium and 137Caesium fallout in a forest soil under spruce. Analyst (London), 117

ED

(1992) 469–474.

[6] NCRP, Radiation exposure of the U.S. population from consumer products and

PT

miscellaneous sources, NCRP report no. 95, Washington DC, 1987.

CE

[7] UNSCEAR, Sources and Effects of Ionizing Radiation, Report to General Assembly, with Scientific Annexes United Nations. United Nations Scientific Committee on the Effects

AC

of Atomic Radiation, United Nations, New York, 2008. [8] J.D. Bliss, Radioactivity in selected mineral extraction industries, A literature Review, Technical Note ORP/LV-79-1, Environmental Protection Agency, Washington DC, 1978. [9] A. Papadopoulos, G. Christofides, A. Koroneos, L. Papadopoulou, C. Papastefanou, S. Stoulos, Natural radioactivity and radiation index of the major plutonic bodies in Greece, J. Environ. Radioactiv. 124 (2013) 227-238.

9

ACCEPTED MANUSCRIPT [10] T. Kovacs, G. Szeiler, F. Fabian, R. Kardos, A. Gregoric, J. Vaupotic, Systematic survey of natural radioactivity of soil in Slovenia, J. Environ. Radioactiv. 122 (2013) 70-78. [11] A. El-Taher, F. Alshahrib, R. Elsaman, Environmental impacts of heavy metals, rare earth elements and natural radionuclides in marine sediment from Ras Tanura, Saudi Arabia along the Arabian Gulf, Appl. Radiat. Isot. 132 (2018) 95-104.

SC RI PT

[12] M.A. Hannan, N. Nguyen, M. Rivas, Natural radioactivity and its gamma dose rate in Mission (Texas) soils, J. Radioanal. Nucl. Chem. 295 (2013) 729–736.

[13] B. Mitrovic, J. Ajtic, M. Lazic, V. Andric, N. Krstic, B. Vranjes, M. Vicentijevic, Natural and anthropogenic radioactivity in the environment of Kopaonik mountain, Serbia,

NU

Environ. Pollut. 215 (2016) 273-279.

[14] N. Yıldız, B. Oto, Ş. Turhan, F.A. Uğur, E. Gören, Radionuclide determination and

MA

radioactivity evaluation of surface soil samples collected along the Erçek Lake basin in eastern Anatolia, Turkey. J. Geochem. Explor. 146 (2014) 34–39.

ED

[15] F. Caridi, S. Marguccio, A. Belvedere, G. Belmusto, Measurements of Gamma Radioactivity in River Sediment Samples of the Mediterranean Central Basin, Am. J.

PT

Condens. Matter Phys. 5 (2015) 61-68.

CE

[16] M.O. Isinkaye, H.U. Emelue, Natural radioactivity measurements and evaluation of radiological hazards in sediment of Oguta Lake, South East Nigeria, J. Radiat. Res. Appl.

AC

Sci. 8 (2015) 459-469.

[17] L. Xinwei, Z. Xiaolan, W. Fengling, Natural radioactivity in sediment of Wei River, China, Environ. Geol. 53 (2008) 1483-1489. [18] M. Malta, J.M. Oliveira, L. Silva, F.P. Carvalho, Radioactivity from Lisboa urban wastewater discharges in the Tejo River Estuary, J. Integr. Coast. Zone Manag. 13(2013) 399-408. [19] M.L. Montes, R.C. Mercader, M.A. Taylor, J. Runco, J. Desimoni, Assessment of natural radioactivity levels and their relationship with soil characteristics in undisturbed

10

ACCEPTED MANUSCRIPT soils of the northeast of Buenos Aires province, Argentina, J. Environ. Radioact. 105 (2012) 30-39. [20] O.K. Adukpo, A. Faanu, H. Lawluvi, L. Tettey-Larbi, G. Emi-Reynolds, E.O. Darko, C. Kansaana, D.O. Kpeglo, A.R. Awudu, E.T. Glover, P.A. Amoah, A.O. Efa, L.A. Agyemang, B.K. Agyeman, R. Kpordzro, A.I. Doe, Distribution and assessment of

SC RI PT

radionuclides in sediments, soil and water from the lower basin of river Pra in the Central and Western Regions of Ghana, J. Radioanal. Nucl. Ch. 303 (2015) 1679–1685. [21] M.T. Kolo, S.A.B. Abdul Aziz, M.U. Khandaker, K. Asaduzzaman, Y.M. Amin, Evaluation of radiological risks due to natural radioactivity around Lynas Advanced

NU

Material Plant environment, Kuantan, Pahang, Malaysia, Environ. Sci. Pollut. Res. 22 (2015) 13127–13136.

MA

[22] H. Faghihian, D. Rahi, M. Mostajaboddavati, Study of natural radionuclides in Karun river region, J. Radioanal. Nucl. Ch. 292 (2012) 711–717.

ED

[23] G. Darko, A. Faanu, O. Akoto, A. Acheampong, E.J. Goode, O. Gyamfi, Distribution of

AC

CE

187 (2015) 339.

PT

natural and artificial radioactivity in soils, water and tuber crops, Environ. Monit. Assess.

11

ACCEPTED MANUSCRIPT Table 1. The radionuclide and gross-α/β activity concentrations of water samples in spring and summer (Bq/L) Spring 238

U

137

Cs

232

Th

Summer 40

K

Gross-α

Gross-β

238

137

U

232

Cs

40

Th

K

Gross-α

Gross-β

15.04

0.01

0.66

0.71

21.95

BDL

BDL

2.59

12.79

BDL

BDL

T P

W1

4.42

BDL

12.7

22.13

0.01

BDL

3.33

BDL

W2

4.25

0.30

6.20

10.37

BDL

BDL

2.09

0.59

W3

7.45

BDL

2.90

28.18

BDL

BDL

3.57

BDL

W4

8.91

0.52

9.27

25.41

BDL

0.96

2.89

BDL

11.95

14.00

BDL

0.16

W5

4.27

BDL

3.52

26.27

BDL

0.25

3.43

BDL

6.02

19.88

BDL

0.12

W6

1.75

0.31

4.28

32.50

0.01

0.14

2.41

0.29

3.21

22.64

BDL

0.37

W7

3.43

BDL

6.96

20.74

BDL

BDL

6.29

21.43

0.11

BDL

W8

1.67

BDL

7.49

22.99

0.01

M

2.38

0.33

4.20

BDL

5.84

21.61

BDL

0.15

W9

2.84

BDL

5.80

6.40

0.02

BDL

6.10

BDL

5.98

31.29

BDL

0.50

W10

2.27

BDL

3.59

10.56

BDL

0.82

4.77

0.23

5.14

23.96

BDL

0.72

W11

4.11

BDL

4.73

22.99

BDL

0.61

7.36

BDL

6.87

22.13

BDL

0.04

W12

3.35

0.27

5.08

27.14

BDL

BDL

4.01

BDL

4.91

35.95

0.03

BDL

Min.

1.67

0.27

2.90

6.40

0.01

0.14

2.09

0.29

0.71

12.79

0.01

0.04

Max.

8.91

0.52

12.7

28.18

0.02

0.96

7.36

0.59

11.95

35.95

0.11

0.72

Mean

4.06

0.35

6.04

21.31

0.01

0.56

3.88

0.37

5.18

21.89

0.05

0.34

PT

E C

C A

D E

0.78

2.63

C S U

I R

N A

BDL: Below detection limit

12

ACCEPTED MANUSCRIPT Table 2. The radionuclide and gross-α/β activity concentrations of sediment samples in spring and summer (Bq/kg) Spring 226

137

226

137

232

S1

42.79

7.10

57.79

5.44

38.32

10.29

64.09

S2

32.68

1.52

0.81

2.55

68.06

2.01

S3

23.58

420.11

0.22

2.64

24.33

5.35

S4

54.25

1042.27

3.70

5.90

60.71

3.33

71.21

1186.62

3.73

6.35

31.14

2.57

48.76

1206.84

1.77

4.16

S7

33.06

1.24

24.76

449.12

0.67

2.02

S8

66.17

1.33

94.45

1645.03

3.82

S9

85.29

6.01

118.07

1722.59

S10

64.52

8.26

82.48

1690.92

S11

26.38

3.09

36.69

S12

45.08

2.90

31.31

Min.

23.58

1.24

Max.

85.29

Mean

44.93

Ra

Cs

232

Summer 40

Th

K

Gross-α

Gross-β

1170.35

2.34

20.64

456.46

4.20

25.75

34.02

3.28

S5

54.41

S6

Gross-β

1189.60

2.06

5.59

27.82

575.09

0.97

2.45

25.29

400.64

0.62

0.70

4.32

84.77

1467.80

4.37

5.03

64.46

0.73

88.74

1501.98

3.61

4.12

28.52

2.11

46.26

1005.65

2.01

4.23

38.38

1.86

27.90

478.83

0.83

1.47

6.06

72.22

0.30

93.19

1500.77

4.26

4.75

2.33

8.22

64.46

17.92

103.49

1371.29

6.44

6.51

1.56

7.76

65.54

10.96

96.23

1457.86

4.50

5.27

715.51

0.91

4.06

23.46

2.19

36.41

515.99

0.60

3.35

1.23

3.97

51.75

1.93

28.49

650.91

2.29

2.60

20.64

420.11

0.22

2.02

23.46

0.30

25.29

400.64

0.60

0.70

8.26

C A

691.97

118.07

1722.59

3.82

8.22

72.22

17.92

103.49

1501.98

6.44

6.51

3.74

55.51

1033.15

1.92

4.93

50.02

4.99

60.22

1009.70

2.71

3.84

PT

E C

Th

K

T P

I R

C S U

N A

M

Cs

40

Gross-α

D E

Ra

13

ACCEPTED MANUSCRIPT Table 3. Comparison of activity concentrations of radionuclides in river water and sediments with different areas of the world Sediment/Soil (Bq/kg) 137Cs

232Th

40K

Reference

Turkey

-

-

27

524

[14]

Italy

25.1

-

28.1

809.8

[15]

Nigeria

47.89

-

55.37

1023

[16]

China

33.1

-

21.8

Spain

-

1.6

-

Argentina

27-69

-

3-41

Present Study

47.48

4.37

RI

PT

226Ra

[17]

328

[18]

531-873

[19]

NU

SC

833.3

57.87

1021.4

MA

Water (Bq/L)

137Cs

232Th

40K

Reference

Spain

-

<0.35

-

328

[18]

Hungary

2.51

-

1.71

41.43

[20]

Malaysia

-

-

0.37

4.82

[21]

-

-

4.93

80.09

[22]

0.32

-

0.40

4.09

[23]

3.97

0.36

5.61

21.6

PT E

AC

Present Study

CE

Iran Ghana

D

238U

14

ACCEPTED MANUSCRIPT Table 4. The radiation hazard parameters of the sediment samples Spring

Summer

Req (Bq/kg)

Dout (nGy/h)

AED (μSv/y)

Hex

Hin

Req (Bq/kg)

Dout (nGy/h)

S1

215.6

96.23

118.02

0.58

0.70

221.6

98.98

S2

97.3

42.72

52.39

0.26

0.35

152.1

65.57

S3

92.8

40.74

49.96

0.25

0.31

91.3

S4

191.9

85.15

104.43

0.52

0.61

S5

247.6

108.3

132.82

0.67

0.82

S6

193.8

87.5

107.31

0.52

S7

103.1

44.78

54.92

0.28

S8

327.9

143.71

176.25

S9

386.8

167.87

205.88

S10

312.7

139.23

S11

133.9

59.47

S12

143.1

63.06

Hex

Hin

121.39

0.60

0.70

80.42

0.41

0.59

40.15

49.24

0.25

0.31

129.55

158.88

0.80

0.96

307.0

134.13

164.5

0.83

1.00

0.61

172.1

77.0

94.43

0.47

0.54

0.37

115.2

49.88

61.17

0.31

0.42

0.89

1.06

321.0

139.55

171.14

0.87

1.06

1.05

1.28

318.0

139.06

170.54

0.86

1.03

170.75

0.84

1.02

315.4

138.14

169.42

0.85

1.03

72.93

0.36

0.43

115.3

50.07

61.41

0.31

0.38

77.34

0.39

0.51

142.6

62.43

76.56

0.39

0.53

D E

T P E

C C

A

AED (μSv/y)

SC

A M

U N 294.9

I R

T P

15

ACCEPTED MANUSCRIPT Figure Captions

AC

CE

PT

ED

MA

NU

SC RI PT

Figure 1. Approximated location of sampling sites

16

Fig.1

AC

CE

PT

ED

MA

NU

SC RI PT

ACCEPTED MANUSCRIPT

17

ACCEPTED MANUSCRIPT Highlights

AC

CE

PT

ED

MA

NU

SC RI PT

1. This research is first detailed database for this area and will be radiological baseline. 2. The radiological baseline in the Lake Van basin was investigated. 3. Radiation hazard parameters (Req, Dout, AED, Hin, Hex) were calculated. 4. Gamma-ray spectrometer with HPGe detector and gross-α/β-counting system were used. 5. In some samples, Req, Hex and Hin values were higher than worldwide average values.

18