Effects of Electromagnetic Fields on Mental Health of the Staff Employed in Gas Power Plants, Shiraz, 2009
The aims of this study are to assess, in a power station in Shiraz, the effects of noise and electromagnetic field on psychological mood. By the great industrial and technological improvements human beings have been exposed to different types of physical and chemical factors. Some of these factors such as electromagnetism are known as the constant components of the environment. According to the studies carried out in one of the power stations in Shiraz, psychological disorders caused by jobs are among the most important problems of the workers. This study is performed to determine the presence or absence of these psychological disorders. This cross-sectional study is performed on these groups : (1) The gas power plant staff who were in contact with electromagnetic field and nose, (2) employees who were only exposed to noise and (3) a group of staff employed in the administrative parts of the Telecommunication companies who did not have any history of being exposed to electromagnetic field and sounds. The General Health Questionnaire (GHQ) is used in this study to recognize psychosomatic disorders. Measurements indicate that range of electromagnetic field varies from 0.087 micro Tesla in the phone homes to 30 micro Tesla in power stations. The results of this study has shown that a significant number of staff which were exposed to electromagnetic fields and noise (78.2%) were suspected to have a kind of mental disorders. The results obtained from this study which shows the prevalence of mental disorders among the suspected case is higher than the results of Noorbala and colleagues study in 2006.
Received: March 03, 2010;
Accepted: August 02, 2010;
Published: September 17, 2010
Because of the great industrial developments, technological changes and modernity
of human life more and more exposures to various physical and chemical factors
have been occurred. In the industrial world, almost everyone is unavoidably
exposed to ambient electromagnetic field (EMF) generated from various technical
and household appliances (Khaki et al., 2008).
Although, many of these factors are because of scientific improvements and
they are new but some such as electromagnetic fields are in the category of
constant environmental factors. Furthermore, due to several parameters, including
the extreme usage of machines, the existence of power transmission lines and
the establishment of high-voltage power plants electromagnetic fields are more
and more involved in the privacy of human life (Zahir al-Din
and Hezaveh, 2003). Electromagnetic field has a great influence on creatures,
so its effects on the various aspects of vital systems are among the common
issues that researchers are interested about. Based on the research results
which emphasis on the adverse effects of electromagnetism especially on human
beings, the anxiety about starting protective appliances has been raised, even
among the government administrators. This increasing anxiety revolutionized
some protective methods and health indexes. On the other hand, it made the researchers
to find out some exact points about the human interaction with this natural
phenomenon and also to provide some realistic solutions for the mentioned problem
(Yousefie and Noori, 2005).
Although, scientific and technological improvements of the recent century provide
a much more comfortable life for humans, but it is important to note that these
improvements can cause harmful effects too. These threatening effects can be
produced by several factors such as the harmful chemical, physical, microbiological
or ergonomical factors. One of the physical harmful factors of the environment
is electromagnetic fields. Electromagnetic field is created due to the passing
of electricity in wires and high potential electrical systems such as the electric
motors (generators), drilling machines and cables of transmission lines (Van
Wijngaarden et al., 2000). Today due to the extreme usage of electrical
equipments, exposure of humans to electromagnetic field has increased. Industrial
workers such as the power station staff are affected by the electromagnetic
radiations induced by electrical equipments and power transmission lines. The
influence and effects of electromagnetic field produced by electrical equipments
are significant, so these effects especially those which affect biological systems
are discussed a lot in scientific circles. Although, electrical forces usually
do not have much influence on creatures, the electromagnetic radiations which
exist in the surroundings of electrical equipments, electricity transmission
lines and electrical high voltage posts significantly affects vital systems.
The symptoms which are proved to be caused by electromagnetic field in human
are headache and fatigue and a direct relation between exposures of electromagnetic
field and higher prevalence of cancer has been proved (Sobel
et al., 1996). Although mental disorders cause less mortality
rate than most of other diseases, but it is important to study them because
of the following reasons.
||According to the past studies mental problems, caused by work,
are acceptable as one of the most important problems of workers
||In some industrial units like electrical power stations, harmful agents
that can cause neurological and psychological disorders are detectable.
Physical factors such as sound and electromagnetic fields, mechanical factor
and chemical agents are some examples for these harmful factors
||Patients with mental disorders not only can harm themselves, but also
they can make dangerous situations for others, especially while they are
working with machines
||The problems that workers have in their job can easily affect their family
(Gamberala, 1990). Similar researches have been
performed in many different countries. However, they have only determined
the effects of the electromagnetic field or noise on their studies. For
the first time, this study has been done to determine simultaneously the
effects of noise and electromagnetic field on psychological mood in Shiraz
MATERIALS AND METHODS
This research project was conducted from July, 2008 to March, 2009 to assess
job relation psychological changes affected from some hazard physical agents
like noise and electromagnetic field. This cross-sectional study is performed
on these groups:
||The gas power plant staff that were in contact with electromagnetic
field and nose
||Employees who were only exposed to noise
||A group of staff employed in the administrative parts of the Telecommunication
companies who did not have any history of being exposed to electromagnetic
field and sounds
All employees of the gas power plant of Shiraz and all the communication company
staff were participated in this study. All the participants were similar in
employment condition, income, education and work time. In this study the general
health questionnaire was used for data gathering. This auto run questionnaire
has been designed for evaluating mental health and mental disorders in societies.
It is also useful in recognizing functional disabilities and finding distributing
factors in social and economical life of adults. This questionnaire is not diagnostic
but it's valuable in screening mental disorders (Beale et
In general the usage of this updated psychological questionnaire is to identify
individuals with mental disorders. It can distinguish mental disorders with
less than 2 weeks duration and it is sensitive to transient disturbances. The
questionnaire has four scales each consist of seven questions that can evaluate
four categories of psychological disorders that are: (1) somatization syndrome,
(2) anxiety and sleep disorders (3) social dysfunctions and (4) depression (Zamanian
Ardekani et al., 2008; Zamanian et al.,
2010). Studies show that the validity and reliability score of this test
is 0.84 to 0.93 (Yousefie and Noorie, 2005 and 0.68
to 0.94) (Vicente et al., 2006; Fakhari
et al., 1999). In this study the Likert scaling method is used for
analyzing datas. We also use descriptive and inferential statics. Descriptive
statics was used in two-dimensional tables and data analyzing. Inferential statics
including Chi-square and one-way ANOVA was used when needed. Upon completion
of field survey and data collection, data was coded and transferred into the
computer for further analysis. Statistical analyses were performed using SPSS
version 9 (SPSS 9.9.9; SPSS Inc, Chicago, Illinois, USA).
In modern society, humans are commonly exposed to electromagnetic field inducing
extremely low frequency electromagnetic field, which is generally produced by
power lines and many kinds of electric appliances (Farkhad
et al., 2007).
|| Some personal details of workers who participated in the
study (n = 165)
|| Mental health status of workers
Electromagnetic field measurements (Table 1) show a variable
range: from 0.087 micro Teslas in phone center to 30 micro Teslas in power station.
It is notable that the maximum amount is 11 times less than the allowed threshold
(TLV) that is 60 micro Teslas.
Relationship between physical health, social dysfunction, anxiety, depression
and work experience, smoking, having shift work, education was not meaningful
(p>0.05). The only exception is the relation between social dysfunction,
depression, having shift work and education which was significant (p<0.05).
This study shows that the quality of mental health in groups which were exposed
to ELE electromagnetic field is less than the unexposed groups. The health index
among the office staff is 63.3% while it is 49.1% among the group which was
exposed to sound. Note that the office staff and the group expose to sound are
supposed as the electromagnetic unexposed group. The health index for the group
which was exposed to electromagnetic field is estimated about 21.8%. Due to
the epidemiologic studies the prevalence of mental disorders in Iranian norm
society is about 11.9 to 23.8% (Noorbala et al., 2004)
while it is 78.2% for staff in contact with electromagnetic field which is three
times more than the society norm (Table 2).
The results of this study indicate that the prevalence of mental disorders
among groups of staff which were exposed to electromagnetic field and noise
is significant (78.2%) (Table 2). Due to the results obtained
from the fourfold scaled questionnaire 94.5% of these people were suspected
to have social dysfunctions too 61.8% of them showed symptoms of anxiety and
sleep disorders 18.2% of them were depressed and 54.5% had complains about physical
symptoms. Prevalence of 78.2% which is obtained from this study is higher than
the results of Noorbala's research which was done in 2004 with the usage of
General Health Questionnaire. According to Zahir al-Din
and Hezaveh (2003) research the incidence of mental disorders is not correlated
with factors such as marital status, age, work experience and shift working.
This study shows that 17% of cases in the exposed group and 32.7% of cases
in the control (unexposed) group are suspected to have mental health disorders.
Yousefi and Noorie (2005) research that is about the effects of electromagnetic
field on mental health (shows that exposed cases) have symptoms of depressing,
obsession (intellectually and practically) and anxiety. Average of the symptoms
severity in the electromagnetic exposed group shows a meaningful difference
with the control group. Because of the complex combination of biological, psychological
and social factors that are contributed with mental health, we need more researches
to find out the exact effects of electromagnetic fields. Not only being exposed
to electromagnetic field is known as a risk factor for mental disorders but
also mental health is related with job characteristics and mental fatigue. Gamberela
(1990) studies show that among workers in high voltage electricity posts that
were exposed to electromagnetic field there are cases with symptoms of depression,
paranoid disease, obsession (intellectual and practical), anxiety and aggression.
In another study carried out by Bethwaite et al.
(2001) and colleagues it is shown that among inhabitants which live near
electromagnetic fields of power transmission lines (50 Hz) and high voltage
posts the prevalence of psychological disorders such as suicide, depression
and lack of attention control is considerable.
||Comparison of prevalence at health status in gas power plant
workers and other study population
Yousefi and Noorie (2005) research indicates that electromagnetic field affects
hematopoietic system. It also shows that the prevalence of symptoms of mental
and behavioral disorders among people expose to electromagnetic field is significantly
higher than the control group, but this higher prevalence is not correlated
with field intensity and duration of contact. Also, Elhag
et al. (2007) showed that electromagnetic field may affect biological
systems by increasing free radicals, which appear mainly to enhance lipid peroxidation
and by changing the antioxidase activities of human blood thus leading to oxidative
stress. Van Wijngarden et al. (2000) study which was about electromagnetic
field exposures shows that the rate of suicide among people employed in places
with electromagnetic field exposures has increased which can be the result of
the higher prevalence of depression among them. In the present study the effectiveness
of electromagnetic fields on the nervous system was evaluated and the initial
pre hypothesis, which indicates the negative role of electromagnetic field on
mental health, was confirmed. In this study the measured incidence of depression,
anxiety, physical health, social disorders and general health is meaningfully
different from other researches (Table 3).
Due to the study results, the following items are recommended in order to prevent
the risk factors which threat the general health of workers who are exposed
to electromagnetic field.
||Examinations before employment and measuring physical and
mental ability of workers are useful
||Periodic examinations and regular psychological counseling can lead to
early diagnosis and treatment of mental disorders and is very important
||Providing consulting services and treatments can promote worker's health
status. It can also cause positive individual, social and economical effects
||Optimizing work environment and controlling harmful factors such as heat,
light, noise, vibration, etc. that can affect mental health of workers is
||Set working hours and resting time properly in order to prevent fatigue
||Encourage workers to exercise by providing sport halls in production centers
||Use dielectric or wave-absorbent clothes
Shiraz University of Medical Sciences and Shiraz Gas Power Plan are highly appreciated for their support.
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