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QUANTIFICATION OF RADIONUCLIDE LEVELS IN HORSE
CHESTNUT SEEDS
Yokubova Nilufar Jamshidovna
Tashkent Pharmaceutical Institute
*e-mail: nilufaryokubovapharmi21@gmail.com
https://doi.org/10.5281/zenodo.12684945
Abstract
Radionuclides are unstable forms of elements that emit radiation, and they
are hazardous pollutants that can have a significant impact on the environment,
the food chain, and human health. These substances persist in the environment
for a long time, potentially causing soil, water, and air contamination, which
poses risks to ecosystems and human populations. When present in soil and
groundwater, radionuclides can be absorbed by plants, leading to potential
radiation exposure for people who consume contaminated plant parts.
Therefore, it is important to analyze the radionuclide content in the seeds of
horse chestnuts grown in different regions. In a recent study, we analyzed the
concentration of radioactive isotopes, including Strontium-90 and Caesium-137,
in horse chestnut seeds using Atomic Absorption Spectroscopy (AAS) in
accordance with Sanitary Rules and Regulations. The findings from this study
revealed that the levels of radioactive isotopes detected in horse chestnut seeds
obtained from both Tashkent City and Qibray district met the requirements
outlined in Sanitary Rules and Regulations (SanPiN № 0193-06).
Key words:
horse chestnut,
radionuclides, radioactive isotopes, Sanitary
Rules and Regulations.
1. Introduction.
Radionuclides, which are unstable forms of elements that emit radiation
[1], pose a significant threat to the environment, the food chain, and human
health. Naturally occurring radionuclides can be found in the air, water, and soil
[2]. These hazardous pollutants can have far-reaching implications and require
careful consideration in environmental and public health management. Indeed,
interest in researching the uptake of radionuclides from soil into vegetation has
heightened due to concerns regarding the potential for deposited radioactivity
to permeate food chains, thus posing a risk to human health through ingestion.
This concern has prompted the establishment of the field of radioecology,
dedicated to investigating the movement of radionuclides along environmental
pathways and accurately quantifying their transfer rates between various
components of ecosystems. This multidisciplinary field encompasses the study
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of the behavior and fate of radioactive substances in the environment, including
their uptake by plants and potential impact on human populations [3]. The
principal sources of radioactive waste and contamination include the generation
of electrical power and nuclear weapons from nuclear fuels, nuclear weapons
testing, fuel reprocessing, and nuclear incidents. Although significant quantities
of contaminated soil and water arise from low- and intermediate-level wastes,
these account for only a minor proportion of the overall radioactivity. Most of
the radioactivity comes from high-level waste (HLW) and spent nuclear fuel
(SNF) [4]. The isotope Strontium-90 carries a greater environmental impact
compared to other isotopes due to its notably extended half-life of 28.1 years [5].
Similarly, Cesium-137 fallout has served as a widely accepted environmental
indicator, effectively detailing historical contamination of the environment by
fission products [6]. Thus, we analyzed the amount of radioactive isotopes,
including Strontium-90 and Caesium-137, in horse chestnut seeds using Atomic
Absorption Spectroscopy (AAS) in accordance with Sanitary Rules and
Regulations. The results of the research indicated that the amounts of
radioactive isotopes identified in horse chestnut seeds collected from Tashkent
City and Qibray district were in compliance with the standards specified in
Sanitary Rules and Regulations (SanPiN № 0193-06).
2. Materials and methods.
Preparation of a solution of lanthanum chloride.
To prepare a solution
of lanthanum chloride, 26.7 grams of lanthanum chloride heptahydrate are
placed into a 100 ml volumetric flask, dissolved in 0.125M hydrochloric acid,
and then diluted to volume with the same solvent.
Preparation of the primary standard solution of strontium.
The
primary standard solution of strontium is prepared by placing 0.715 grams of
previously dried at 300 °C for 3 hours, cooled in a desiccator for 2 hours,
strontium chloride into a 1000 ml volumetric flask, dissolving it in 50 ml of
water, and then diluting it to volume with water. The resulting solution contains
400 mkg of strontium in 1 ml.
Preparation of the standard solution of strontium.
A standard solution
of strontium is prepared by taking 5 ml of the primary standard solution, placing
it into a 20 ml volumetric flask, and diluting it to volume with 0.125 M
hydrochloric acid. The resulting solution contains 100 mkg of strontium in 1 ml.
Preparation of the primary standard solution of caesium.
Approximately 500 mg (accurately weighed) of caesium powder is dissolved in
50 ml of 6M hydrochloric acid in a 1000 ml volumetric flask, diluted to volume
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with water, and mixed. The resulting solution contains about 500 mkg of
caesium in 1 ml.
Preparation
of
the
standard
solution
of
caesium
. 2 ml of the primary
standard solution of caesium is placed into a 100 ml volumetric flask and diluted
to volume with a solution of 0.125M hydrochloric acid. The resulting solution
contains about 10 mkg of caesium in 1 ml.
Preparation of a test solution.
For the test solution, 1 gram of seeds is
added to 60 ml of concentrated hydrochloric acid (36,5 -38%) and heated in a
water bath, periodically rinsing the inner surface of the crucible with a solution
of 6M hydrochloric acid, for 30 minutes. The solution is then cooled and placed
into a 100 ml volumetric flask. The walls of the crucible are washed with a small
amount of a solution of 6M hydrochloric acid and placed into the same flask.
Then the resulting solution is diluted to volume with water, mixed, and filtered
through a membrane filter with a hole diameter of 0.45 µm. The first 5 ml of
filtrate is thrown away.
1.5 ml of the resulting solution is placed into a 50 ml volumetric flask and
diluted to volume with 0.125M hydrochloric acid. Then 2 ml of the resulting
solution is placed into a 200 ml volumetric flask and 2 ml lanthanum chloride
solution is added. This solution is diluted to volume with 0.125M hydrochloric
acid and mixed (the concentration of the solution is about 0.4 mkg/ml).
Absorption of standard and test solutions is sequentially detected at
wavelengths of 460.7 nm (strontium) and 852.1 nm (caesium) using an atom-
absorption spectrophotometer equipped with a hollow strontium and caesium
cathode lamp and an air-acetylene burner.
A 0.125 M solution of 0.1% lanthanum chloride-containing hydrochloric
acid is used as a standard solution. Based on the obtained results, a calibration
curve is compiled, and the concentration of the test solution is determined in
mg/kg using the resulting graph.
3. Results and discussion.
The levels of radionuclides, including Strontium-90 and Caesium-137 in
horse chestnut seeds collected from Tashkent City and Qibray district were
meticulously analyzed using AAS
(Fig.1).
№
Name
of
radionuclides
Sanitary
Rules
and Regulations
(SanPiN № 0193-
06).
Amount
of
radionuclides
in
seeds
collected
from
Tashkent,
Amount
of
radionuclides
in
seeds
collected
from
Qibray,
SCIENCE AND INNOVATION IN THE
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mg/kg
mg/kg
1 Strontium-90
Less than 7,96
mg/kg
1,301·10
-5
1,095·10
-5
2 Caesium-137
Less than 79,64
mg/kg
1,293·10
-5
1,186·10
-5
Figure 1: Results of the analysis of the radionuclides strontium-90 and
caesium-137 in horse chestnut seeds collected from Tashkent city and
Qibray district.
The results revealed that the horse chestnut seeds from Tashkent
contained 1,301•10-5 mkg/kg of Strontium-90 and 1,293•10-5 mkg/kg of
Caesium-137, while the seeds from Qibray contained 1,095•10-5 mkg/kg of
Strontium-90 and 0,186•10-5 mkg/kg of Caesium-137. In accordance with
Sanitary Rules and Regulations (SanPiN № 0193-06), it is stipulated that the
quantity of Strontium-90 must not exceed 7.96 mg/kg, and that of Caesium-137
should not surpass 79.64 mg/kg. The findings indicate that the levels of
radionuclides present in horse chestnut seeds are fully compliant with the
established standards.
4. Conclusion.
The horse chestnut seeds collected from Tashkent City and Qibray district
underwent a thorough analysis using Atomic Absorption Spectroscopy (AAS) to
detect and measure the presence of radionuclides, specifically Strontium-90 and
Caesium-137. The comprehensive studies conclusively demonstrate that the
levels of radionuclides in the seeds from both Tashkent City and Qibray district
meet the strict requirements outlined in the Sanitary Rules and Regulations
(SanPiN № 0193-06). This detailed analysis confirms that the horse chestnut
seeds comply with established health and safety standards and are safe to use
References:
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Sons.
2. Masarik, J. (2009). Origin and distribution of radionuclides in the continental
environment. Radioactivity in the environment, 16, 1-25.
3. Bell, J. N. B., Minski, M. J., & Grogan, H. A. (1988). Plant uptake of radionuclides.
Soil Use and Management, 4(3), 76-84.
4. Hu, Q. H., Weng, J. Q., & Wang, J. S. (2010). Sources of anthropogenic
radionuclides in the environment: a review. Journal of environmental
radioactivity, 101(6), 426-437.
SCIENCE AND INNOVATION IN THE
EDUCATION SYSTEM
International scientific-online conference
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5. Budnitz, R. J. (1974). Strontium-90 and strontium-89: a review of
measurement techniques in environmental media.
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