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Analysis and Evaluation of Specific Absorption Rate of GSM Signal in Port Harcourt, Nigeria

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There is a growing concern in the world that residents close to GSM base station facilities are exposed to electromagnetic radiation which causes different health illness like cancer, leukemia, memory lost, dizziness, fatigue, etc. This study puts to rest the position on the effect of radiofrequency (RF) radiation from GSM masts on human health. In this research work, the evaluation and assessment of radio frequency radiation in five selected mobile base stations facilities in Obio/Akpor Local Government of Rivers State, Nigeria were carried out using an EMF meter for measurement of Electric field. The measurements of the radio frequency radiation with the EMF meter was conducted from 0 – 300m away from the selected base transceivers stations facilities of the selected telecommunication operators (MTN, Globacom and Airtel) in Nigeria. The data obtained from the research were analyzed using Specific Absorption Rate formula to establish whether with time exposure to RF radiation will have negative impact on human health. The normal specific absorption rate (SAR) and the Power Density for the general public whole body was assessed from the measured electric field strength and the results were compared with that of International Commission on Non Ionization Radiation Protection (ICNIRP).The results showed that the average amount of SAR for the selected five base transceiver station (BTS) facilities were within the range of 0.0037 W/kg – 0.0084 W/kg and the power density 1.5183 W/m2 – 9.5083 W/m2. These values are lower than the recommended limit by ICNIRP which is 0.08w/kg for the human body. This study has shown that there is inconsequential effect on human health because the non-ionizing electromagnetic energy has no sufficient energy to affect any part of human body for the residents living close to the selected BTS facilities of the various telecommunication providers.
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*Corresponding author: Email: elechi.promise@ust.edu.ng;
Journal of Engineering Research and Reports
5(4): 1-10, 2019; Article no.JERR.49579
Analysis and Evaluation of Specific Absorption Rate
of GSM Signal in Port Harcourt, Nigeria
Promise Elechi
1*
, Sunny Orike
1
and Promise Agugharam
1
1
Department of Electrical Engineering, Rivers State University, Port Harcourt, Nigeria.
Authors’ contributions
This work was carried out in collaboration among all authors. Author PA designed the study,
performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript.
Authors PE and SO managed the analyses of the study. Author PE managed the literature searches.
All authors read and approved the final manuscript.
Article Information
Editor(s):
(1) Dr. Pierre-Olivier Logerais, Associate Professor, Department of Energy Systems, Université Paris-Est Créteil, France.
(2)
Dr. Leandro A. Pasa, Professor, Campus Medianeira da Universidade Tecnologica Federal do Parana, Brazil.
Reviewers:
(1) Julie Ogbulezie, University of Calabar, Nigeria.
(2)
Aliyu Bhar Kisabo, National Space Research and Development Agency, Nigeria.
Complete Peer review History:
http://www.sdiarticle3.com/review-history/49579
Received 30 March 2019
Accepted 15 June 2019
Published 21 June 2019
ABSTRACT
There is a growing concern in the world that residents close to GSM base station facilities are
exposed to electromagnetic radiation which causes different health illness like cancer, leukemia,
memory lost, dizziness, fatigue, etc. This study puts to rest the position on the effect of
radiofrequency (RF) radiation from GSM masts on human health. In this research work, the
evaluation and assessment of radio frequency radiation in five selected mobile base stations
facilities in Obio/Akpor Local Government of Rivers State, Nigeria were carried out using an EMF
meter for measurement of Electric field. The measurements of the radio frequency radiation with
the EMF meter was conducted from 0 300m away from the selected base transceivers stations
facilities of the selected telecommunication operators (MTN, Globacom and Airtel) in Nigeria. The
data obtained from the research were analyzed using Specific Absorption Rate formula to establish
whether with time exposure to RF radiation will have negative impact on human health. The normal
specific absorption rate (SAR) and the Power Density for the general public whole body was
assessed from the measured electric field strength and the results were compared with that of
International Commission on Non Ionization Radiation Protection (ICNIRP).The results showed
that the average amount of SAR for the selected five base transceiver station (BTS) facilities were
within the range of 0.0037 W/kg – 0.0084 W/kg and the power density 1.5183 W/m
2
9.5083
W/m
2
. These values are lower than the recommended limit by ICNIRP which is 0.08w/kg for the
Original Research Article Original Research Article
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
2
human body. This study has shown that there is inconsequential effect on human health because
the non-ionizing electromagnetic energy has no sufficient energy to affect any part of human body
for the residents living close to the selected BTS facilities of the various telecommunication
providers.
Keywords: Electromagnetic field; BTS; SAR; ICNIRP.
1. INTRODUCTION
Telecommunication facilities require a network of
towers, antennas and associated structure to
host the network devices. Habitually, slope tops
are great areas since they empower signals to be
picked up from and transmitted to an expansive
zone. With increasing demand for mobile
telephone services as a result of high population
and technology awareness, there has been a
significant increase in the demand for such
facilities. Today in Nigeria, masts are erected
even in the compounds of living homes with little
or no consideration of the effects on the health of
the people. This study is to find out the amount of
radiation emanating from these BTS facilities and
check immediate and long-term impact if there
are any on the environment and the people living
very close to these facilities.
This study evaluates the electromagnetic field
strength of selected base stations of the
telecommunication service providers (MTN,
Globacom and Airtel) within some communities
(Rumuolumeni, Rumuchakara, Akwaka, Woji and
Eliozu) in Obio/Akpor local government of Rivers
State. The study is aimed at analyzing and
evaluating the specific absorption rate (SAR) due
to GSM BTS signals and check if they meet
International Commission on Non-Ionization
Radiation Protection (ICNIRP) standards and
limit.
The result of this research work can serve as a
working document for imminent radio frequency
(RF) radiation from the selected BTS facilities
because there has not been any research carried
out in the mapped-out area to the knowledge of
the researcher.
1.1 Literature Review on Electromagnetic
Field from Base Transceiver Station
Facilities
Both positive and negative electric charges
generate electric field in a stable or moving
situation. The current caused by moving charges
is main source of magnetic field. Time varying
electric and magnetic fields are accompanied to
each other to produce an electromagnetic field.
After that, electromagnetic waves which radiate
from BTS facilities are produced by these time
varying electromagnetic fields [1]. Related work
[2] in their study observed that the
electromagnetic radiation emitted by mobile
phone base stations was measured in terms of
electric field strength as a function of distance.
The measured values were used to calculate
specific absorption rate of the skin and brain
tissue to assess the health risks. Certain
directions were found to be safer than the other
directions. Results has shown that the values of
the SAR for the eight base stations selected for
the study were within the range of 0.00010 W/kg
to 0.0012 W/kg Also, [3-4], in their studies
showed that long term exposure to radiation from
the base stations causes different ailments such
as cancer cases, prostate, breast and lungs
cancer. Other forms of ailment caused by mast
location as reported are that of leukemia,
lymphoma and hematopoietic which damaged
blood cells, untimely death, fever, migraine as a
result of vibration and contamination of
environment due to the pollution from generators.
They found out that there is a substantial
relationship between mast location and health of
the inhabitants [4]. Santini et al. [5] confirmed
further the effect of telecommunication mast on
the health of people of United Kingdom in which
they observed that mast operators around the
Northern United Kingdom were inquired by the
inhabitants and local authority to clear their
telecommunication masts due to the negative
impacts on the inhabitants. They reported
twenty-seven (27) cases of collapsed masts
tower as a result of weather problem.
2. METHODOLOGY
2.1 Materials and Methods
A detailed procedure was followed to
determine the existence of the masts
inside residential areas. This study emphasizes a
lot on the quantity of electromagnetic
radiation emanating from these GSM base
transceiver stations (BTS) in Obio-Akpor
local government area. The materials and
instruments used in the study are Measuring
Tape, Stop Watch, TES 593 Electrosmog
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
3
(EMF) Meter, Data Recording Sheet, GPS Meter
and Mobile Phone.
The Electrosmog meter by TES Electrical
Electronic Corporation USA (model TES-593
serial No 006P 9V- 090200180) was used for the
measurements. The device is a handheld
broadband meter for detecting high-frequency
radiation in the range from 50 MHz - 3.5 GHz. It
is a non-directional digital 3-axis radio frequency
(RF) handling meter. It is an effective meter for
digital RF signals and equally very sensitive (2
V/m to 100 V/m).
2.2 Measurement Approach
For each of these locations, measurements from
GSM BTS facilities were carried out in five
different locations in Obio/Akpor LGA. The data
were collected from the three major telecom-
munication operators (MTN, Globacom and
Airtel) masts to ascertain the amount of
radiations emitted from these base stations.
The masts are located at Rumuolumeni,
Akwaka, Rumuchakara, Eliozu and Woji
all in Obio/Akpor Local Government of Rivers
State, Nigeria. For each of these locations the
measurements of electromagnetic radiation were
taken at 50m, 100m, 150m, 200m, 250m and
300m every 10 minutes.
In order to collect accurate and reliable data
the three telecoms companies (MTN, Globacom
and Airtel) visited with different locations are
shown Table 1.
Fig. 1. Picture of MTN Mast visited at Rumuolumeni
Fig. 2. Picture of airtel mast visited at Akwaka
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
4
Fig. 3. TES – 593 Electrosmog (EMF) meter
Fig. 4. Block diagram of measurement
Table 1. Measurement locations and their coordinates
S/N
SITE ID
LOCATION
COORDINATE (Degree)
1 MTN 4232 Rumuolumeni – 3 Ohiamati street, Police
post bus stop.
Longitude:
7.05659099
Latitude:
4.785383159
2 IHS_PHC 116 Choba – Rumuchakara Road, Choba Longitude:
6.995768598
Latitude:
4.830232823
3 IHS_PHC161 Rumuodumaya – Akwaka Road Longitude:
7.0364968
Latitude:
4.8716169
4 MTN 3456 Eliozu – New Eliozu Road Longitude:
6.987324968
Latitude:
4.905511315
5 PAR 174 Woji – Abec Road, off ALCON Longitude:
7.061797107
Latitude:
4.872241849
Received
Electromagnetic
BTS Facility RF EMF Meter Measurement
Result
Received Power
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
5
2.3 SAR Evaluation and Standards
Specific Absorption Rate (SAR) is the quantity of
energy which the human body can absorb when
exposed to radiofrequency electromagnetic field.
SAR computation was derived from Maxwell’s
equations. E and H are first determined
analytically or numerically from Maxwell’s
equations. The unit of SAR is Watt per kilogram.
It can be calculated from E using equation (1) [6].
An EMF meter detects the electric field strength
E and converts it into magnetic field strength H
and power density S. The meter measures E
along three different axes but can also take
readings of all the Es’ at the same time when set
to the triaxial mode of operation. The electric field
(E), the magnetic field (H) are all related to
power density (S) expressed in Watts per
meter squared (W/m
2
) as shown in the equation
below.
2
2
377
377
H
E
EHS
(1)
where 377 Ω is the characteristic impedance of
vacuum.
2
// E
SAR
(2)
where
σ is the electrical conductivity (S/m)
E is the electric field strength (V/m)
ρ is mass density of the medium (kg/m³)
Using the electric fields, the dissipated power
density, S in any tissue can also be calculated
using the following equation:
S = σ|E|
2
= ρSAR (3)
This also implies that;
S
E
SAR
2
//
(4)
Equation (2) is a point equation, so it is often
called the resident SAR. The space-average
SAR for a body or a part of the body is obtained
by calculating the resident SAR at each point in
the body and averaging over the part of the body
being considered.
3. RESULTS AND DISCUSSION
To analyze the results, the specific absorption
rate (SAR) was first determined and the
graphical analysis in other to establish whether
exposure to GSM base station has effect or no
effect on human health for a long period of time.
All the telecom service providers (MTN,
Globacom and Airtel) antennas were made to
radiate 1800 MHz; they have the following
specifications Globacom, MTN and Airtel have
down link frequency of 1820 – 1835 MHz, 1835 –
1850 MHz, 1850 1865 MHz, uplink frequency
of 1725 – 1740 MHz, 1740 – 1755 MHz and
1756 – 1770 MHz, respectively. Shown in Figs. 5
and 6 below are the variations of SAR and power
density with distance for all the 5 base station
sites used for this study. Summarized in Figs. 7
and 8 are the average SAR and power density
values for the 5 base stations for site
comparison.
Table 2. Summary of ICNIRP’s general public safety guidelines for limiting radiation exposure
and SAR
Frequency
E-Field
(V/m)
H-Field
(A/m)
Power density
(W/kg)
Whole body
SAR (W/kg)
Localized
(head) (W/kg)
400-2000MHz
1.375f
½
0.003f
½
f/200
0.08
2
2-300 GHz 61 0.16 10 0.08 2
Table 3. Summary of average SAR and power density at distance 50m – 300m
Site
Network provider
SAR
Power density
Rumuchakara MTN 0.0066 4.9466
Awaka Airtel 0.0037 4.1083
Woji Globacom 0.0084 9.5083
Rumuolumeni MTN 0.0043 1.5183
Eliozu Globacom 0.0052 2.5267
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
6
Fig. 5. SAR versus distance from the five selected BTS stations
Fig. 6. Power density versus distance from the five selected BTS stations
3.1 Compared Result and ICNIRP
Standards
In Figs. 9 and 10, the highest radiation levels
were observed at a distance of 50 m, 100 m and
150m from sites 1-5 respectively and the SAR
values in W/Kg ranged from 0.0037 W/kg
0.0084 W/kg and power density ranged from
1.5183 W/m
2
9.5083 W/m
2
which are quite
lower than the maximum safety standard
limit (0.08 W/kg for whole body exposure)
set by the International Commission on Non-
ionizing Radiation protection (ICNIRP).
The ICNIRP standards state that for any
frequency between 400-2000MHz used, it must
be divided by 200 (f/200) to determine the
required limit for power density. The
Telecommunication service providers (MTN,
Globacom and Airtel) antennas radiate
between 900 1800 MHz; this implies
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
7
that the limit for power density for this research
work is:
f = 1800
f/200 = 1800/200 = 9.00 W/m
2
From Fig. 10, it can be observed that the highest
power density came from the Woji base
station (9.5083 W/m
2
) which is slightly above
9.00 W/m
2
with a difference of 0.5083 W/m
2
.
3.2 Root Mean Square Deviation
The root-mean-square deviation (RMSD) or
root-mean-square error (RMSE) is a frequently
used measure of the differences between values
(test and population values) predicted by a model
or an estimator and the values really observed.
It serves to aggregate the extents of the errors
in forecasts for different times into a single
measure of prescient power [7]. The Root
Mean Square Deviation is given by [8]:
RMSD =
 
N
xx
ii
N
i
2
1
ˆ
(5)
where:
= the actual observation values
= the estimated or forecasted standard limit
given value
= the number of data entry
Table 4 shows that even with the fluctuations of
radiation the root mean square deviation values
for specific absorption rate and the power density
for the different locations falls within the ICNIRP
set standards.
Fig. 7. Average SAR from the five selected BTS stations
Table 4. Summary of RMSD for SAR and power density
Location
RMSD (SAR)
RMSD (Power Density)
Woji 0.071654 2.7969
Eliozu 0.074877 6.67188
Awaka 0.076257 5.2681
Rumuolumeni 0.072794 7.5104
Rumuchakara 0.073746 5.2294
i
x
i
x
ˆ
N
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
8
Fig. 8. Average power density from the five selected BTS stations
Fig. 9. ICNIRP SAR standards and research values
Elechi et al.; JERR, 5(4): 1-10, 2019; Article no.JERR.49579
9
Fig. 10. ICNIRP power density standard and research values
4. CONCLUSIONS
The electromagnetic radiation emitted by mobile
phone base stations was measured in terms of
electric field strength as a function of distance.
The measurements were done in five BTS
stations belonging to three different GSM
network (MTN, Globacom and Airtel) operators in
the study locations. The measured values were
used to calculate specific absorption rate of the
whole-body tissue and power density to assess
the health risks. Certain directions were found to
be safer than the other directions. Results show
that the values of the SAR and power density for
the five base stations selected for the study are
within the range of 0.0037 W/kg to 0.0084W/kg
and 1.5183W/m
2
9.5083W/m
2
respectively.
These values are quite lower than the limit by
International Commission on Non–ionizing
Radiation Protection (ICNIRP) which is 0.08
W/kg [9,10,11] for the whole-body average SAR.
This demonstrates that there is no significant
health risk for the residents that stay in the
vicinity of the selected base stations for the
various mobile service provider of the area.
COMPETING INTERESTS
Authors have declared that no competing
interests exist. The products used for this
research are commonly and predominantly use
products in our area of research and country.
There is absolutely no conflict of interest
between the authors and producers of the
products because we do not intend to use these
products as an avenue for any litigation but for
the advancement of knowledge. Also, the
research was not funded by the producing
company rather it was funded by personal efforts
of the authors.
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© 2019 Elechi et al.; This is an Open Access article distributed under the terms of the Creative Commons Attribution License
(http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.
Peer-review history:
The peer review history for this paper can be accessed here:
http://www.sdiarticle3.com/review-history/49579
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There is a general concern on the possible hazardous health effects of exposure to radiofrequency electromagnetic radiations (RFR) emitted from mobile phone base station antennas on the human nervous system. To identify the possible neurobehavioral deficits among inhabitants living nearby mobile phone base stations. A cross-sectional study was conducted on (85) inhabitants living nearby the first mobile phone station antenna in Menoufiya governorate, Egypt, 37 are living in a building under the station antenna while 48 opposite the station. A control group (80) participants were matched with the exposed for age, sex, occupation and educational level. All participants completed a structured questionnaire containing: personal, educational and medical histories; general and neurological examinations; neurobehavioral test battery (NBTB) [involving tests for visuomotor speed, problem solving, attention and memory]; in addition to Eysenck personality questionnaire (EPQ). The prevalence of neuropsychiatric complaints as headache (23.5%), memory changes (28.2%), dizziness (18.8%), tremors (9.4%), depressive symptoms (21.7%), and sleep disturbance (23.5%) were significantly higher among exposed inhabitants than controls: (10%), (5%), (5%), (0%), (8.8%) and (10%), respectively (P<0.05). The NBTB indicated that the exposed inhabitants exhibited a significantly lower performance than controls in one of the tests of attention and short-term auditory memory [Paced Auditory Serial Addition Test (PASAT)]. Also, the inhabitants opposite the station exhibited a lower performance in the problem solving test (block design) than those under the station. All inhabitants exhibited a better performance in the two tests of visuomotor speed (Digit symbol and Trailmaking B) and one test of attention (Trailmaking A) than controls. The last available measures of RFR emitted from the first mobile phone base station antennas in Menoufiya governorate were less than the allowable standard level. Inhabitants living nearby mobile phone base stations are at risk for developing neuropsychiatric problems and some changes in the performance of neurobehavioral functions either by facilitation or inhibition. So, revision of standard guidelines for public exposure to RER from mobile phone base station antennas and using of NBTB for regular assessment and early detection of biological effects among inhabitants around the stations are recommended.
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Thors B, Strydom M, Hansson B, Meyer F, Krkkinen K, Zollman P, Ilvonen S, Tornevik C. Estimation of SAR and compliance distance related to RF exposure from mobile communication base station antennas. IEEE Trans. Electromagnet. Compact. 2008;50(4):837-848.