| Research Article |
Open Access |
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| DNA hazard in Furnace Operating Workers from a Power Plant |
| Kır T1, Durmaz E2, Ulutas OK2, Cok I2 and Donbak L1* |
| 1Kahramanmaras Sutçu Imam University, Science and Arts Faculty, Department of Biology, Kahramanmaras, Turkey |
| 2Gazi Universities, Faculty of Pharmacy, Department of Toxicology, Ankara, Turkey |
| *Corresponding author: |
Lale Donbak
Kahramanmaras Sutçu Imam University
Science and Arts Faculty, Department of Biology, Kahramanmaras, Turkey
Tel:
+90 344 219 1412
Fax: +90 344 219 1042
E-mail: lale@ksu.edu.tr |
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| Received November 04, 2011; Accepted December 03, 2011; Published
December 05, 2011 |
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| Citation: Kır T, Durmaz E, Ulutas OK, Cok I, Donbak L (2011) DNA hazard in
Furnace Operating Workers from a Power Plant. J Carcinogene Mutagene 2:124.
doi:10.4172/2157-2518.1000124 |
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| Copyright: © 2011 Kir T, et al. This is an open-access article distributed under
the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and
source are credited. |
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| Abstract |
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| The aim of this study was to investigate the possible DNA damage in workers occupationally exposed to coal
combustion products in furnace section of Afsin-Elbistan A power plant (Turkey). With this purpose, venous blood
samples collected from 36 male power plant workers were analysed by comet assay for determining the level
of DNA tail intensity. The obtained results were compared with those of control group consisting of 34 healthy
male individuals. The data comparison showed that mean frequency of tail intensity was significantly higher in
workers as compared to control group (P<0.05), respectively 9.94±2.51 and 8.48±2.31. Present study indicated the
DNA damage in the peripheral lymphocytes of furnace operators, possibly due to the several chemical compounds
present in the coal ash and gaseous emissions. |
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| Keywords |
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| Coal fired power plant; Afsin-Elbistan A; Power plant
workers; Genotoxic risk; Comet assay |
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| Introduction |
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| Thermal power plants leads to the emission of significant amounts
of SO2 and fine particulate matter, volatile organic compounds (VOCs)
and toxic organic micro pollutants, such as polycyclic aromatic
hydrocarbons (PAHs) into the environment [1,2]. These products of
combustion represent a risk to both environment [3,4] and human
[5,6]. Considering increased coal production and utilization, several
researchers concerned with the safety and health of the workers
who utilize coal and expose to coal combustion products in various
workplace. Epidemiological studies have shown that exposure to PAHs
is associated with time- and dose-dependent increases in risk of cancer
namely lung, colon, and bladder, and adverse birth outcomes [7-9].
Beside, other concents of coal combustion products such as coal ash,
quartz, carbon, nitrogen, and sulfir oxides, and trace elements have
been reported to lead to various types of cancer [10,11] and also have
been shown to be mutagenic and genotoxic by several studies [12-15]. |
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| A few studies concerning the genotoxic risks of workers
occupationally exposed to coal combustion products in power plants,
reported a significant increase in the level of chromosomal aberrations
(CA), in acentric chromosome fragments and dicentric chromosome
as well as the number of abnormal cells, sister chromatid exchanges
(SCE), micronucleus (MN), and polyploid cells in workers as compared
to control group [16,17]. |
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| In the present study, possible genotoxic risk of workers exposed
to coal combustion products in the furnace section of Afsin-Elbistan
A power plant, located in South-eastern Turkey, were investigated
by comet assay. Afsin-Elbistan an established in 1983 is an old power
plant where the pollution control is insufficient. So, the workers
were exposed to the combustion products of coal-mixture of volatile
substances and also coal ash, especially in the furnace. |
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| Materials and Methods |
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| Subjects and sampling |
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| A total of 36 furnace operators from Afsin-Elbistan A power plant
(south-eastern Turkey) and 34 healthy male from Kahramanmaras
city (160 km far from the power plant) consented to participate in the
study. The workers and control group were selected after questionnaire administration for obtaining information regarding age, occupation,
and years of employment, life style, and health problems, if any. The
years of exposure of the workers range between 9-28 years, the mean
value was 21±3.22. The mean age of the workers was 46.46±4.77 years
(range 37-53), it was 46.06±5.81 (range 32-55) for the control group.
Venous blood samples of 5 ml were taken in heparinized tubes at
the working site, codified and immediately transported at 4°C to the
Toxicology Laboratory of Pharmacy Faculty (Gazi University, Ankara)
for Comet assay. |
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| Comet assay (Single-cell gel electrophoresis-SCGE) |
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| The comet assay was performed under alkaline conditions using the
method described previously by Sing et al. (18) with slight modification.
The isolated lymphocytes (with Histopaque 1077 in phosphate buffer
salin on ice) from heparinized blood samples were suspended (at ~2
× 105 cells/mL) were mixed with 100 μl of 0.65% low-melting-point
agarose in PBS at 37°C and rapidly pipetted onto a frosted glass
microscope slide precoated with 100 ml of 1% agarose, spread out with
a coverslip and maintained at 4°C for 30 min to solidify. After removal
of the coverslip, the slides were immersed in lysis solution (2.5 M NaCl,
100 mM Na2EDTA, 10 mM Tris, NaOH to pH 10.0, and 1% Triton
X-100) for overnight at 4°C, to remove cellular proteins. Slides were
initially placed in an electrophoresis tank containing 1 mM Na2EDTA
and 300 mM NaOH, (pH 13) for 20 min. Afterward, the tank was set
at 25 V (1.6 V/cm, 300 mA) for 20 min at an ambient temperature
of 4°C. The slides were then washed three times for 5 min each, with
Tris buffer (0.4 M Tris, pH 7.5), at 4°C before staining them with 65 μl
ethidium bromide (EtBr 20 μg/ml) for analyzing. Analysis was carried out immediately after sample collection without freezing or storing.
Cell viability, using trypan blue, was found to be over 95% at each time
point of the study. |
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| After the staining process, hundred cells were analysed using double
slides selected randomly for examination at x200 magnification under
a fluorescent microscope (Zeiss-Axioskop, Oberkochen, Germany)
equipped with an excitation filter 515–560 nm and a 100 W Hg lamp.
DNA migration (tail intensity) was measured, using Comet Assay III
image analysis system (Perceptive Instruments, UK). All slides were
coded and scored blindly. |
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| Statistical analysis |
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| The data were analysed with SPSS 15.0 for Windows statistical
programme (SPSS, Chicago, IL). Differences between control
and exposed groups were evaluated by the Mann-Whitney U test.
Correlations between different variables were analysed by Spearmen’s
rho correlation test. For all statistical analyses, a level of at least 0.05
was used to determine significance. |
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| Results and Discussion |
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| The effects of exposing to coal combustion products in the furnace
section of Afsin-Elbistan A power plant on the tail intensity selected as
a marker of the genotoxic damage were presented in Table 1. Workers
showed a significantly higher mean tail intensity (9.94±2.51) compared
to the unexposed control subjects (8.48±2.31) (P<0.05). |
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Table 1: The mean tail intensity in workers and controls. |
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| We also analysed the data with respect to years of exposure and
age of the individuals, to investigate the association between the
marker and independent variables (Table 2). The results obtained from
Spearman’s rho correlaton analysis revealed no significant correlation
between the years of exposure and tail intensity in workers (P>0.05). In
neither workers nor controls subjects, the incidence of markers, show a
significant correlation with age (P>0.05). |
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Table 2: Spearman’s rho correlation analysis between tail intensity and
independent variables. |
|
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| As compared to studies done to performed the environmental
impact of energy production by coal, a few researches are available
on the health risk of the workers occupationally exposed to coal
combustion products in the power plants. In a study from Italy [19],
malignant mesothelioma has been reported in power plant workers. In
a study [20], the lung function impairment and respiratory symptoms
have been reported in the power plant workers exposed to high level
of coal ash. Beside, a possible lung and pleural cancer risk have been
demonstrated in some studies from Italia and U.K. [21,22]. |
|
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| Concerning to genotoxic risk of power plant workers, Bauman and
Horvat [23] found significantly higher CA level in workers of a power
station burning coal, than in control group. In another study, Leonard
et al. [17], reported a significant increase in acentric chromosome
fragments and dicentric chromosome as well as the number of
abnormal cells in workers from coal fueled power plant as compared to
control group. Beside, Celik at al. [24], reported considerably elevated
CA, SCE, and MN levels in the peripheral lymphocytes of workers
exposed to waste coal ash in a power plant. Moreover, the frequency of
the polyploid cells was found to be significantly higher in the workers
than in control subjects. |
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| In the present study, the observed increase of DNA damage level
in workers in terms of tail intensity were consistent with the previous
cytogenetic studies [17,23,24] reported the genotoxic risks in the
workers occupationally exposed to chemical products of burning
coal and ashes. Elevated level of DNA damage might originate from
the many chemical compounds present in the coal ash and also in
the gaseous emissions. The mixtures of these compounds may exhibit
additive interactions that can not be predicted by the any single
substance. |
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| Acknowledgements |
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| We would like to thank Research Fund of Kahramanmaras Sutcu Imam
University for supporting to the study (Grant No. 2007/1-7). |
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