Experimental radionuclides in soil-plant complex of agroecosystem near Issyk-Kul

EXERIMENTAL

RADIONUCLIDES

IN

SOIL-PLANT

COMPLEX OF AGROECOSYSTEM NAER ISSYK-KUL

Issyk-Kul region is situated in the eastern

part of the Kyrgyz Republic. The territory of the

region is divided into five administrative districts:

1. the Ton district 2. the Issyk-Kul district, 3. the

Tup district, 4. the Ak-Suu district, 5. the

Jeti-Oguz district.

Climate conditions of Issyk-Kul hollow is

good for the development of the agrarian sector

of the economy. The average annual temperature

is +5 C, precipitation often falls during the

spring- summer period from 300 to 700mm.

Area of arable land is 184000 hectares. The

soils are dark-chestnut, chestnut and light-grey.

Principally cultivated plants are annual herbs

60-70 thousand hectares, cereals 80-90 thousand

hectares, potatoes 4-5 thousand hectares and

trees 4 thousand hectares. Stock-breeding is

developing in the region.

Experimental radionuclide refer to the number of

more important environment pollutants, and taking global

scale of radioactive contaminations and increase natural

radiation significance was acknowledged as one of the

important negative changes in the modern biosphere.

In connection with this, the fundamental purpose of

this work was to define and study the behavior of long-lived

radionuclides strontium-90 and caesium-137 in soil-plant

complex of agroecosystem near Issyk-Kul.

Proceeding from this main purpose was the following

purpose:

1. Definition of the level of specific activities of

strontium-90 and caesium-137 in the soil.

2. Studying vertical and horizontal migration of these

radionuclides in the soil.

3. Definition of their level of accumulation in agricultural

cultures.

4. Definition of specific activities of strontium-90 and

caesium-137 in the water of the lake Issyk-Kul.

5. Definition of the level of accumulation of these

radionuclides in the river and lake deposits.

SPECIFIC ACTIVITIES OF STRONTIUM-90 AND CAESIUM– 137 IN THE SOIL OF AGROECOSYSTEM NEAR ISSYK-KUL

№ _{Test area Strontium – 90 in the soil (Bq/kg) Caesium – 137 in the soil (Bq/kg)}

Limit of

fluctuation average Limit of fluctuation average

1. Jetioguz region 2,02-4,81 3,13 3,51-9,99 6,0 2. Ton region 2,11-3,27 3,10 3,18-5,14 4,15 3. Issyk-Kul region 2,18-4,21 2,88 4,40-8,36 5,99 4. Tup region 2,07-6,51 3,95 4,02-11,51 7,18 5. Ak-Suu region 2,54-3,76 3,18 4,81-8,88 7,10 6. By regions 2,02-6,51 3,25 3,18-9,99 6,08

VERTICAL MIGRATION OF STRONTIUM-90 AND CAESIUM-90 IN THE SOIL OF THE HIGH MOUNTAIN PASTURES NEAR ISSYK-KUL

№ _Horizon

(cm) Test area Strontium-90 in the soil (Bq/kg) Caesium-137 in the soil (Bq/kg)

Limit of

fluctuation average fluctuationLimit of average

1. _0-5 Peak 3,97-5,37 4,67 8,68-9,32 9,01 2. _{5-10 0,29 0,29 0,69-0,75 0,72} 3. _{10-15 0,27 0,27 0,38-0,51 0,45} 4. _{15-20 0,29 0,29 0,42 0,42} 5. _{20-50 0,09 0,09 0,28 0,28} 6. _{50-100 0,15-0,16 0,15 0,17-0,19 0,18}

7. 0-5 Foot 8,45-9,4 8,92 15,4-16,3 15,8 8. 5-10 0,75 0,75 0,35 0,35 9. 10-15 0,33-0,36 0,34 0,21-0,51 0,36 10. 15-20 0,55 0,55 0,3 0,3 11. 20-50 0,21 0,21 0,19 0,19 12. 50-100 0,15-0,16 0,15 0,61-0,65 0,63 13. 0-5 Plain 0,24-0,36 0,23 1,08-1,38 1,25 14. 5-10 0,66-0,67 0,66 0,23-0,29 0,26 15. 10-15 0,12-0,19 0,15 0,26 0,26 16. 15-20 0,15-0,16 0,16 0,55-0,59 0,57 17. 20-50 0,53-0,79 0,66 0,35 0,35 18. 50-100 0,21 0,21 -

-Selection was made at an altitude of 3000 meters above the sea level in three places: on the peak, middle and slope of foot with the distance of 200 meters from one another. From every selection place was tested the soil samples by horizon: 0-5 cm, 5-10 cm, 10-15 cm, 15-20 cm, 20-50 cm, 50-100 cm.

SPECIFIC ACTIVITIES OF STRONSIUM-90 AND CAESIUM-137 IN AGRICULTURAL CULTURES OF AGROECOSYSTEM NEAR ISSYK-KUL

№ Cultures Strontium-90 in plants (Bq/kg) Caesium-137 in plants (Bq/kg) Limit of

fluctuation average Coefficient ofaccumulation fluctuationsLimit of average Coefficient ofaccumulation

1. Winter crops (grain) 0,99-2,11 1,67 0,51 0,55-2,58 1,34 0,22 2. Spring crops (grain) 2,03 2,03 0,62 1,66 1,66 0,27 3. Corn (foliage) 1,26-1,44 1,59 0,48 2,94-5,56 3,82 0,62 4. Potatoes(tuber) 1,15-1,40 1,27 0,39 1,42-2,33 1,87 0,31 5. Esparto (root) 1,26-2,85 1,78 0,54 1,59-5,17 3,63 0,59 6. Lucerne (root) 1,14-2,76 1,83 0,56 3,23-3,85 3,57 0,58 7. Different herbs (root) 2,89-3,7 2,79 0,85 8,21-9,73 8,97 1,47

1. TEST RESULTS OF RADIOCHEMICAL ANALYSIS OF THE WATER IN LAKE ISSYK- KUL CONCENTRATION OF STRONTIUM-90 AND CAESIUM-137

№ Strontium-90 in the

water (Bq/l) Caesium-137 in the water (Bq/l)

Limit of

fluctuation average drinking water NRS -99 for fluctuationLimit of average drinking water NRS -99 for

1. 0,015-0,036 0,021 5,0 0,043-0,065 0,055 0,22

2. TEST RESULTS OF RADIOCHEMICAL ANALYSIS OF THESE DEPOSIT IN THE MOUTH OF RIVERS FALLING INTO LAKE ISSYK-KUL CONCENTRATION OF STRONTIUM-90 AND CAESIUM-137

№ Strontium-90 in

deposit (Bq/kg) deposit (Bq/kg)Caesium-137 in

Limit of the

fluctuation average LPL in these _deposits Limit of the fluctuation

average LPL in these deposits

№ Strontium-90 in

deposit (Bq/kg) Caesium-137 in deposit (Bq/kg)

Limit of

fluctuation average LPL in this deposit fluctuationLimit of average LPL in this deposit

1. 1,88-5,18 2,86 48 2,66-5,11 3,88 46

3.TEST RESULTS OF RADIOCHEMICAL ANALYSIS OF THESE LAKE DEPOSIT OF ISSYK-KUL CONCENTRATION OF STRONTIUM-90 AND CAESIUM-137

TEST OF RESEARCH IS ESTABLISHED

1. Specific activities of strontium-90 and

caesium-137 in the soil of agroecosystem near

Issyk-Kul to be within the limit of natural

significance for unpolluted territory.

2. In the main these radionuclides are

surrounded in the top of the soil horizon

(0-25cm) and their specific activity decrease with

depth.

3. The accumulation of these radionuclides are

absent in the cultivating agricultural cultures in

the regions.

4. Specific activities of strontium-90 and

caesium-137 in the water and the lake deposit of

Issyk-Kul, also in the river deposit falling into the

lake are the lowest in established limit of