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Effects of Electromagnetic Radiation from Microwave Ovens on Workers' Health at Cafeterias in some Higher Educational Institutions in Palestine

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Abstract This study highlights the effects of electromagnetic radiation from microwave ovens on the health of the workers who are exposed to this radiation during their work at cafeterias in four higher educational institutions in Palestine. To achieve the aim of the study, the researcher focused on a sample that consists of 28 workers whose ages range between 20-55 years. Measurements of heart pulse rate, blood oxygen saturation, tympanic temperature, systolic and diastolic blood pressure were taken three times between (8:00-8:30) am and another three times at the same day after the end of their using of the microwave ovens at around 2:00 till 2:30 pm. The average of these measurements was taken. The study was carried out during December 2013 and January 2014. The researcher of this study focused on four higher education institutions in the northern part of Palestine. These higher educational institutions are An-Najah National University, the Arab American University, Hisham Hijawi College, and Palestine Technical University. The gathered data were subjected to statistical analysis. The results demonstrate that the average of the measured values of radiation leakage equals 46.126 mW/m2. The average values of radiation leakage are small compared with the standard value which equals 5×104 mW/m2 recorded by American National Standard Institute. It has been concluded that there is a correlation between radiation leakage from microwave ovens with oven's age, distance from oven, and the duration of use. Using measurable health parameters to detect the effect on workers' health reveals that there is a change in the measurable parameters, but that change remains in the normal human range. That is, there is no dangerous health effects of microwave radiation from microwave ovens used in the cafeterias of the university under study, which indicates adopting high security factors in designing modern microwave ovens.
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An-Najah National University
Faculty of Graduate Studies
Effects of Electromagnetic Radiation from Microwave
Ovens on Workers' Health at Cafeterias in some
Higher Educational Institutions in Palestine
By
Isra’ Ribhi Abu Hadbah
Supervisor
Prof. Issam Rashid Abdelrazi
Co-Supervisor
Dr. Mohammed Abu-Jafar
This Thesis is Submitted in Partial Fulfillment of the Requirements for
the Degree of Master of Physics, Faculty of Graduate Studies, An-
Najah National University, Nablus, Palestine.
2014
III
Dedication
This Thesis is dedicated with gratitude to:
My dear parents for the million things they gave me, for the unlimited
support, care, and love they always give me. My gratitude goes to my
fiancé Fayez for his encouragement and support. I also extend my gratitude
to my sisters and brothers with love and respect.
IV
Acknowledgments
First of all I heartily thank Allah for giving me the will and patience to
undertake this study as a completion to my master's degree. I am also
indebted and deeply grateful to my supervisors Prof. Issam Rashid
Abdelraziq, and Dr. Mohammed Abu-Jafar for their support,
encouragement, and most importantly thier helpful comments on earlier
drafts. I am also grateful to the examining committee members. Special
thanks are due to my grandmother as well as my aunt Nahedah who was
the first to encourage me to pursue my higher studies. I also extend my
gratitude to my uncle Dr. Mamdouh Abu Shehab. Special thanks are due to
my sister safa' for helping me in measurements. Many thanks also go to my
friends for their support.
After all, I would like to thank the cafeterias managers; specially the
manager of the Arab American University cafeteria, Ibrahim Zaghloul.
I would like to thank workers for their cooperation to make this research
possible.
V


Effects of Electromagnetic Radiation from Microwave
Ovens on Workers' Health at Cafeterias in some
Higher Educational Institutions in Palestine

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
Declaration
The work provided in this thesis, unless otherwise referenced, is the
researcher's own work, and has not been submitted elsewhere for any other
degree or qualification.
Student’s name: 
Signature: 
Date: 

VI
List of Contents
No.
Subject
Page
Dedication
III
Acknowledgment
IV
Declaration
V
List of Contents
VI
List of Tables
VII
List of Figures
X
List of Abbreviations
XII
Abstract
XIV
Chapter One: Introduction
1
1.1
Background
1
1.1.1
Instruction of Microwave Oven
2
1.1.2
Operating Principle of Microwave Oven
3
1.2
Literature Review
3
1.3
Objectives of this Study
8
Chapter Two: Theoretical Background
9
2.1
Electromagnetic Spectrum
9
2.2
Absorption of Radiation Energy
10
2.3
Specific Absorption Rate (SAR)
12
Chapter Three: Methodology
13
3.1
Study Sample
13
3.2
Stages of the Study
14
3.3
Timetable of the Study
15
3.4
Standard Exposure Radiation
15
3.5
Measurement and Instrumentation
17
3.5.1
Sound Level Meter 2900
17
3.5.2
Lux Hitester
18
3.5.3
Acoustimeter RF Meter
18
3.5.4
Micro Life Blood Pressure Meter
19
3.5.5
Pulse Oximeter
20
3.5.6
TempScan Thermometer
21
3.5.7
Scan Probe
21
3.6
Statistical Analysis
22
Chapter Four: Results
24
4.1
Light Intensity and Sound Pressure Levels Results
24
4.2
Radiation Leakage from Microwave Ovens
25
4.2.1
Radiation Leakage with Distance
26
4.2.2
Radiation Leakage with Operating Power
27
4.2.3
Radiation Leakage with Duration of Use
28
4.3
Calculation of Specific Absorption Rate (SAR)
28
VII
4.4
Results of Health Parameters
30
4.4.1
Heart Pulse Rate Results
36
4.4.2
Blood Oxygen Saturation Results
37
4.4.3
Tympanic Temperature Results
38
4.4.4
Blood Pressure Results
40
4.5
Data Analysis of Dependent Variables and Radiation
Leakage from Microwave Ovens
42
Chapter Five: Discussion and Conclusion
44
5.1
Radiation Leakage with Distance and Operating
Power
44
5.2
The Effect of Microwave Radiation on Heart Pulse
Rate
44
5.3
The Effect of Microwave Radiation on Blood Oxygen
Saturation
45
5.4
The Effect of Microwave Radiation on Tympanic
Temperature
45
5.5
The Effect of Microwave Radiation on Systolic and
Diastolic Blood Pressure
45
Chapter Six: Recommendations
48
References
49

VIII
List of Tables
Table Caption
Page
Number of examined workers and microwave ovens in
different cafeterias in Palestine
14
Reference levels for power flux density exposure (exposure
levels in mW/m2)
16
Reference levels for general public exposure to time varying
electric and magnetic fields provided by ICNIRP
16
Standard values for SAR in Europe and USA
17
Average values of light intensity level and sound pressure
level in the cafeterias of the selected higher educational
institutions
25
Average values of power flux density, electric field, magnetic
field strength, magnetic flux density in the selected cafeterias
29
Calculated SAR values for some tissues of workers in the
cafeterias used in this study
30
Average values of heart pulse rate, blood oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic, before (b) and after (a) exposure to microwave
radiation for the tested workers
31
Average values of heart pulse rate, blood oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic, before (b) and after (a) exposure to microwave
radiation for groups G1 and G2
32
Percentage change of the average values of heart pulse rate,
blood oxygen saturation, tympanic temperature, and arterial
blood pressure systolic and diastolic for workers age groups
G1 and G2
32
Minimum (min), maximum (max), mean, and standard
deviation values, before (b) and after (a) exposure to
microwave radiation for group G1 (20-34) years old
33
Minimum (min), maximum (max), mean, and standard
deviation values, before (b) and after (a) exposure to
microwave radiation for group G2 (35-55) years old
33
Average values of heart pulse rate, blood oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic, before (b) and after (a) exposure to microwave
radiation for both groups GA and GB
34
Percentage change of the average values of heart pulse rate,
blood oxygen saturation, tympanic temperature, and arterial
blood pressure systolic and diastolic for the workers duration
of employment for both groups GA and GB
34
IX
Minimum (min), maximum (max), mean, and standard
deviation values, before (b) and after (a) exposure to
microwave radiation for workers group GA
35
Minimum (min), maximum (max), mean, and standard
deviation values, before (b) and after (a) exposure to
microwave radiation for workers group GB
35
Pearson correlation coefficient between radiation leakage from
microwave ovens and heart pulse rate, blood oxygen
saturation, tympanic temperature, and systolic and diastolic
blood pressure for all workers in the cafeterias
43
The normal range recommended standards of heart pulse rate,
blood oxygen saturation, tympanic temperature, systolic and
diastolic blood pressure
46
X
List of Figures
No.
Figure caption
Page
1.1
Basic structure of a microwave oven
3
2.1
Electromagnetic Spectrum
9
3.1
Sound Pressure Level Meter Model 2900
17
3.2
Hioki 3423 Lux Hitester Digital Illumination Meter
18
3.3
Acoustimeter RF Meter
19
3.4
Micro Life Blood Pressure Meter
20
3.5
Pulse Oximeter
20
3.6
TempScan Thermometer
21
3.7
Scan Prope
22
4.1
Average values of the measured radiation leakage level at
5 cm distance from microwave ovens in the cafeterias
under study
26
4.2
Radiation leakage from microwave ovens as a function of
distance
26
4.3
Average values of radiation leakage against oven's
operating power
27
4.4
Average radiation leakage from microwave ovens as a
function of duration of use
28
4.5
Average values of heart pulse rate of workers before and
after exposure to microwave radiation of G1 and G2
groups
36
4.6
Average values of heart pulse rate of workers before and
after exposure to microwave radiation of GA and GB
groups
37
4.7
Average values of blood oxygen saturation of workers
before and after exposure to microwave radiation of G1
and G2 groups
37
4.8
Average values of blood oxygen saturation of workers
before and after exposure to microwave radiation of GA
and GB groups
38
4.9
Average values of tympanic temperature of workers
before and after exposure to microwave radiation of G1
and G2 groups
39
4.10
Average values of tympanic temperature of workers
before and after exposure to microwave radiation of GA
and GB groups
39
4.11
Average values of systolic blood pressure of workers
before and after exposure to microwave radiation of G1
and G2 groups
40
XI
4.12
Average values of diastolic blood pressure of workers
before and after exposure to microwave radiation of G1
and G2 groups
41
4.13
Average values of systolic blood pressure of workers
before and after exposure to microwave radiation of GA
and GB groups
41
4.14
Average values of diastolic blood pressure of workers
before and after exposure to microwave radiation of GA
and GB groups
42
XII
List of Abbreviations
Symbol
Abbreviation
Electric permittivity in vacuum
Magnetic permeability in vacuum
Magnetic permeability
µW/cm2
Micro watt per centimeter square
A/m
Ampere per meter
Am
Before midday
AU
The Arab American University Cafeterias
dB
Decibel(s)
DBP
Diastolic Blood Pressure
E
Electric field
EHRS
Environmental Health and Radioactive Safety
ELF
Extremely Low Frequency
EM
Electromagnetic Radiation
FDA
Food and Drug Administration
FM
Frequency Modulation
G1
Group of workers with the age range of 20-34 years
G2
Group of workers with the range age of 35-55 years
GA
Group of workers with duration of employment from 5
months to 5 years
GB
Group of workers with duration of employment from 6 to
10 years
H
Magnetic field strength
HC
Hisham Hijawi College Cafeterias
HPR
Heart Pulse Rate
ICNIRP
International Commission on Non Ionizing Radiation
Protection
IR
Infrared
IRPA
International Radiation Protection Association
J/m2.s
Joule Per meter square second
Lux
Unit of illumination
mos.
Months
NU
An- Najah National University Cafeterias
OSHA
Occupational Safety and Health Administration
P
Probability significant
Pm
After midday
PU
Palestine Technical University Cafeterias
R
Pearson correlation factor
RADAR
Radio Detection And Ranging
XIII
RF
Radio Frequency
RF-
EMR
Radio Frequency Electromagnetic Radiation
RFR
Radio Frequency Radiation
RLS
Radio Location Station
RW
Radio Wave
SAR
Specific Absorption Rate
SARA
Specific Absorption Rate of Workers at the Arab American
University Cafeterias
SARH
Specific Absorption Rate of Workers at Hisham Hijawi
College Cafeteria
SARK
Specific Absorption Rate of Workers at Palestine
Technical University Cafeteria
SARN
Specific Absorption Rate of Workers at An-Najah
National University cafeterias
SBP
Systolic Blood Pressure
Seq
Power flux density
SPO2%
Blood Oxygen Saturation
T
Tympanic Temperature
UV
Ultra Violet
VRT
Visual Reaction Time
W/Kg
Watt per Kilogram
Y
Years
v
The Incremental volume

The Incremental mass

The incremental energy

Absorption coefficient of the substance (Alpha)
Wavelength (Lambda)
Mass density (Rho)
Electrical conductivity of the material (Sigma)
XIV
Abstract Effects of Electromagnetic Radiation from Microwave Ovens
on Workers' Health at Cafeterias in some Higher Educational
Institutions in Palestine
By
Isra’ Ribhi Abu Hadbah
Supervisor
Prof. Issam Rashid Abdelrazi
Co-Suprvisor
Dr. Mohammed Abu-Jafar
Abstract
This study highlights the effects of electromagnetic radiation from
microwave ovens on the health of the workers who are exposed to this
radiation during their work at cafeterias in four higher educational
institutions in Palestine. To achieve the aim of the study, the researcher
focused on a sample that consists of 28 workers whose ages range between
20-55 years. Measurements of heart pulse rate, blood oxygen saturation,
tympanic temperature, systolic and diastolic blood pressure were taken
three times between (8:00-8:30) am and another three times at the same
day after the end of their using of the microwave ovens at around 2:00 till
2:30 pm. The average of these measurements was taken. The study was
carried out during December 2013 and January 2014. The researcher of
this study focused on four higher education institutions in the northern part
of Palestine. These higher educational institutions are An-Najah National
University, the Arab American University, Hisham Hijawi College, and
Palestine Technical University. The gathered data were subjected to
statistical analysis. The results demonstrate that the average of the
measured values of radiation leakage equals 46.126 mW/m2. The average
XV
values of radiation leakage are small compared with the standard value
which equals 5104 mW/m2 recorded by American National Standard
Institute. It has been concluded that there is a correlation between radiation
leakage from microwave ovens with oven's age, distance from oven, and
the duration of use. Using measurable health parameters to detect the effect
on workers' health reveals that there is a change in the measurable
parameters, but that change remains in the normal human range. That is,
there is no dangerous health effects of microwave radiation from
microwave ovens used in the cafeterias of the university under study,
which indicates adopting high security factors in designing modern
microwave ovens.
1
Chapter One
Introduction
1.1 Background
The worldwide technology development has been dramatically increasing.
This generates a great interest by people to follow the evolution of
technology.
Wide exposure to such evolution may lead to environmental pollution
occurs in different forms including, air, water, soil, radioactive, noise,
thermal, and light pollution. The various types of pollution do not simply
negatively affect the natural world, but they can have measurable impact
on human beings (Neelam, and Sanjeev, 2013).
Microwave radiations are used in many areas of science and technology
such as television, radar, and microwave ovens (Gupta, 1988). Moreover
microwave radiation is used to treat muscle soreness, but the most
commonly use is in microwave ovens (FDA, 2006).
Despite the benefits resulting from the use of microwave radiation
application, there are many risks that threaten people's lives and affect
human health. The intensive use of electromagnetic radiation technology
makes the pollution of electromagnetic field of radio frequency generated
by telecommunication system one of the biggest environmental problems
of the twentieth century (Adiloze, et al, 2010).
Microwave oven is one of the important appliances that are mainly used in
homes, restaurants, and cafeterias. The reason for the increasing demand
on this device is to reheat food in an amazingly short time. Microwave
2
ovens play a crucial role in people’s life. For example it can quickly reheat
different kinds of food with no physical change of food. Another benefit of
microwave ovens is related to the place available in the kitchen since it
occupies a small place (Seong-Lee, 2004).
1.1.1 Instruction of Microwave Oven
The microwave oven consists of some parts. Each of these parts plays a
vital role. It consists of a cavity magnetron, a high voltage power source, a
high voltage capacitor, a waveguide, a stirrer, a turntable, a cooking cavity,
a door and a choke. A cavity magnetron is a device which converts high-
voltage electric energy to microwave radiation. A high voltage power
source is a simple electronic power converter. A high voltage capacitor is
connected to the magnetron. A waveguide is a tool to control the direction
of the microwaves. Stirrer is commonly used to distribute microwaves
from the wave guide and allow more uniform heating. Turntable rotates the
food products through the fixed hot and cold spots inside the cooking
cavity. Cooking cavity is a space inside which the food is heated when
exposed to microwaves. Door and choke allows the access of food to the
cooking cavity (Jaime, 2014).
3
Fig. 1.1 Basic structure of a microwave oven
(http://www.tlbox.com/category/appliances/small-appliances/microwave-ovens/)
1.1.2 Operating Principle of Microwave Oven
The most important portion of microwave oven is a magnetron, which is “a
tube in which electrons are subjected to both magnetic and electric fields”.
The electromagnetic field with a microwave frequency of about 2.45 GHz,
wavelength λ = 12.6 cm will produce, according to this alternating
electromagnetic field polar molecules such as water molecules inside food,
will rotate due to absorption of microwave energy. The rotation of water
molecules would generate heat. In addition to the dipole water molecules,
there is another source of heat by ionic compounds in food. As they are
accelerated by electromagnetic field, they collide with other molecules and
produce heat (Priyanka, et al, 2013).
1.2 Literature Survey
During recent years, many scholars have conducted a large number of
studies on the effect of electromagnetic radiation emitted by many sources.
4
For example, Osepchuk, made a review of the safety of microwave ovens.
He has showed that typical leakage values imply exposure values well
below the most conservative exposure standards in the world. Microwave
ovens are being more accepted and safer than they were in 1973
(Osepchuk, 1978).
While evaluating the health risks from exposure to electromagnetic
radiation, Matthes investigated the measurements of radiation emitted from
microwave ovens and he found that detrimental health effects are not
expected to occur as a result of radiation exposure during microwave
cooking (Matthes, 1992).
Kolodynski and Kolodynska from their experiments on school children
living near the Radio Location Station (RLS), they conclude that these
children had less developed memory and attention. Their reaction time was
slower and their neuromuscular apparatus endurance was lowered
(Kolodynski, and Kolodynska, 1996).
Sieber and his team proved that fears can be neglected concerning the
formation of D-amino acids in microwaved milk. A biological experiment
showed that no evidence for the hazards of microwave heat treatment of
milk (Sieber, et al, 1996). Moreover Inaloz and his group in their study
believe that it is not easy to say that microwave ovens have cataract genic
effect on human eyes (Inaloz, et al, 1997).
Alhekail in his study argued that user exposure to RF radiation from
microwave ovens is much less than the public exposure limit set by the
international standard ICNIRP in 1998 at 2.45 GHz which is 104 mW/m2,
5
and that a detrimental effect on health is an unlikely result of exposure to
radiation from microwave ovens (Alhekail, 2001).
On the other hand microwave ovens greatly affected food stuffs, Song and
Milner studied the effect of microwave ovens on garlic. They demonstrated
that heating garlic for 60 second in a microwave oven is enough to
inactivate its allinase, garlic’s principle active ingredient against cancer
(Song, and Milner, 2001).
Radio frequency signals at an average specific absorption rate (SAR) of at
least 5.0 W/kg under extended exposure conditions are capable of inducing
chromosomal damage in human lymphocytes. This research has been
studied by Tice and his group (Tice, et al, 2002).
Vallejo showed that microwave ovens have serious effects on nutrients in
people's food such as broccoli “zapped” in the microwave with a little
water lost up to 97 percent of its beneficial antioxidants. By comparison,
steamed broccoli lost 11 percent or fewer of its antioxidants. There were
also reductions in phenolic compounds and glucosinolates, but mineral
levels remained intact (Vallejo, 2003).
In addition, Kesarik and his team summarized in their research that the
regular and long term use of microwave devices (mobile phone, microwave
ovens) at domestic level can have negative impact upon biological systems
especially on brain (Kesarik, et al, 2003).
Alto and his group found that the electromagnetic field emitted by a
commercial mobile phone affects regional cerebral blood flow in humans
(Aalto, et al, 2006). Radiation from a cell phone penetrates deeper into the
6
head of children. Children may be more susceptible to damage from cell
phone radiation. Children absorb energy differently than adults because of
differences in their anatomies and tissue composition. This has been
summarized by Wiart and his team in 2008 (Wiart, et al, 2008).
A study done by Mailankot and his team to evaluate the effect of radio
frequency electromagnetic radiation(RF-EMR) from mobile phones on free
radical metabolism and sperm quality. They summarized that semen
quality is negatively affected from RF-EMR emitted. Male fertility may
impair by exposure to these radiations (Mailankot, et al, 2009).
Tacken and his group investigate the idea that after low temperature
microwave heating, triglyceride and carotenoid concentration in human
milk remained stable. Therefore, mature human milk can be safely heated
in a microwave oven without loss of fat or carotenoid (Tacken, et al,
2009).
The study conducted by Cinquanta and his team on heating orange juice in
microwave ovens showed that there is a slight decrease in vitamin C
content after microwave heating (Cinquanta, et al, 2010). Han and his
group in their study demonstrated that watching TV and using a mobile
phone during the first term pregnancy may increase risk of embryo growth
ceasing significantly(Han, et al, 2010). A study was done by Mousa to
measure the electromagnetic radiation from some cellular base station
around the city of Nablus. He summarized that the measured and
calculated values of electric field, magnetic field, and the power density
were small compared to the international standards (Mousa, 2011).
7
Robinson and his group in their study argued that children as young as 17
month could start microwave ovens, open the door, and remove the
contents, but these actions may put them at a significant risk for scald burn
injury (Robinson, et al, 2011).
People usually think that, there is a dangerous health problem due to
radiation leakage from microwave ovens. Several experiments carried out
in this field. According to Australian standard it is found that the maximum
allowable leakage from a microwave oven is 5 mW/cm2 at 5 cm distance
from the surface of a microwave oven. The only danger from the exposure
to the radiation emitted by an oven is a thermal effect (Mohammad, et al,
2011). The detrimental effects of microwave radiation emitted by mobile
phones at students in university are studied in 2012. Mortazavi and his
group summarized that the student visual reaction time (VRT) decreased
after exposure to electromagnetic fields generated by specific absorption
rate mobile phone (Mortazavi, et al, 2012).
Lahham and Sharabati in their study found that the amount of radiation
leakage from microwave ovens at a distance 1 m vary from 0.4 to 16.4
µW/cm2 with an average value that equals to 3.64 µW/cm2. They
concluded that there is a linear relation between the amount of leakage
with both oven age and the operating power (Lahham and Sharabati, 2013).
Thambiraj and his group argued that microwave ovens are considered an
important source of injury at home especially among young children in the
United States (Thambiraj, et al, 2013).
8
The effect of electromagnetic field from mobile phones on fasting blood
glucose in Wister Albino rats was determined by Meo and Rubeaan study.
They concluded that there is an increment in fasting blood glucose and
serum insulin in long-term exposure Albino rats (Meo, and Rubeaan,
2013).
1.3 Objectives of the Study
People are aware about the impact of radiation leaking from microwave
ovens on their health. It has been found that generally, cafeterias' workers
use microwave ovens for 6 hours a day. A study done to investigate the
radio frequency radiation leakage from microwave ovens used in different
cafeterias in a group of higher educational institutions in the northern part
of Palestine.
The aims of this study are:
1. To measure the amount of radiation leakage as a function of distance
from microwave ovens, operating power, and oven age.
2. To calculate the electric fields, magnetic fields, and SAR.
3. To detect the effects of the electromagnetic radiation leakage on the
workers by measuring the health factors such as heart pulse rate,
blood oxygen saturation, tympanic temperature, and blood pressure.
9
Chapter Two
Theoretical Background
This chapter consists of three sections. Section one highlights the
electromagnetic spectrum. Section two discusses absorption of radiation.
Finally, section three explains the specific absorption rate (SAR).
2.1 Electromagnetic Spectrum
Electromagnetic spectrum is defined as a series of energy waves composed
of oscillating electric and magnetic fields transmitted through empty space
at the speed of light. It can be described as the complete range of the
wavelength of electromagnetic radiation beginning with the longest
wavelength, the lowest frequency radio waves and extended through the
visible light all the way to the extremely short wavelength and highest
frequency gamma rays (OSHA, 2005).
Fig. 2.1 Electromagnetic Spectrum
10
The electromagnetic spectrum consists of two major kinds of radiations:
1. Ionizing radiation: A radiation that has sufficient energy to ionize
atoms by knocking electrons out of their orbital shells through
breaking the chemical bonds within a molecule. Ionizing radiation
has very high frequency and short wavelength including X-rays, and
gamma rays which are at the upper end of EM spectrum.
2. Non-Ionizing radiation: An electromagnetic radiation that doesn't
have enough energy to ionize matter. It includes, ultraviolet radiation
(UV), visible light, infrared radiation (IR), microwaves (MW), radio
waves (RW) and extremely low frequency (ELF) (EHRS, 2013).
Microwaves are a part of electromagnetic spectrum with frequencies
ranging from 300 MHz to 300 GHz corresponding to wave length range
1 mm to 1m. They fall under non ionizing radiation. In modern world,
microwave radiation of specific frequency range is used for specific
application. Those in (30-300) MHz range are used in FM radio and
television, those with (300 MHz-3 GHz) are used in microwave ovens, and
RADAR (Radio Detection And Ranging). Microwave frequency of (30
GHz-300 GHz) has been assigned for satellite-to-earth communications
(Toshi, et al, 2013).
2.2 Absorption of Radiation Energy
Beer's law deals with the absorption of radiation through materials. It states
that the intensity I of the transmitted beam of radiation at an absorber
decreases exponentially depending on two factors; the absorption
coefficient (α) of the absorber and the path length (x) of the radiation
11
through the absorber (Ingle and Crouch, 1988). Mathematically, it is
expressed as follows:
I = Io (2.1)
Where: I is the transmitted intensity (J/m2.s), Io is the incident intensity
(J/m2.s), α is the absorption coefficient (cm-1), x is the path length (cm).
Energy transferred from an electromagnetic wave which travels through
space into a receiver object has a rate that depends on the strength of
electromagnetic field components. The rate of energy transferred per unit
area is called power density. The power density Seq in W/m2 is defined as
the product of the electric field strength (E) in V/m times the magnetic
field strength (H) in A/m (OSHA, 1990).
Seq = E H (2.2)
For linear materials, the magnetic flux density (B) is related to the
magnetic field strength (H) with the relation
B=µ H (2.3)
Where the constant µ = 4 10-7 T.m/A is the magnetic permeability.
Under the simple conditions of wave travel through free space, the
relationship of electromagnetic fields is reduced to:
E = (
)1/2 H (Under free space conditions) (2.4)
The electric field strength (E) is calculated as:
Seq =
 (2.5)
12
The magnetic field strength (H) is calculated from the relation
Seq = 377 H² (2.6)
Where (
)1/2 = 377 is the characteristic impedance of free space
(OSHA, 1990).
2.3 Specific Absorption Rate
Specific absorption rate (SAR) is used to describe the rate of radio
frequency radiation (RFR) energy absorbed in a unit of tissue in the body.
It is expressed in Watt per kilogram (W/Kg) of tissue. SAR is usually
averaged over the whole body or over small volume tissue typically
between 1 and 10 g of tissue. SAR has more authenticity to determine the
biological effect of radio frequency radiations (RFR's) than power density,
since SAR reflects what is really being absorbed by matter rather than the
energy in space (Levitt, and Lai, 2010).
Mathematically, SAR is defined as the time derivative of the incremental
energy (dW) absorbed by an incremental mass (dm) contained in a small
element of volume (dv) of a given mass density).
SAR =
(
) (2.7)
SAR = 
(2.8)
Where σ is the electrical conductivity of the material, and E is the electric
field inside the material (Vijay, et al, 2012).
13
Chapter Three
Methodology
This chapter focuses on five topics including, study sample (Sec. 3.1),
stages of the study (Sec. 3.2), timetable of the study (Sec. 3.3), standard
exposure radiation (Sec 3.4), and experimental apparatus (Sec. 3.5).
3.1 Study Sample
The sample population of this study consists of 28 workers distributed in
some of cafeterias in four higher educational institutions in the northern
part of Palestine. These workers are the only workers which use
microwave ovens while working inside cafeterias. The study focuses on
cafeterias in specific higher educational institutions which are An-Najah
National University that is in Nablus city, the Arab American University
which is located in Jenin city, Hisham Hijawi College is in Nablus city,
and Palestine Technical University which is in Tulkarm city.
The workers' ages range between 20 to 55 years. The shift time of the
workers is 6 hours per day. The chosen workers have good health records.
The sample population of this study also involves 15 microwave ovens
with uniform size used in the cafeterias of the selected higher educational
institutions. These cafeterias use microwave ovens for 6 hours a day.
Light intensity is measured in different sites in the region of microwave
ovens in the cafeterias under study. Values are found to vary from (200-
600) Lux. These values are in the normal range of the light intensity. The
sound pressure level was (50-60) dB which is considered to be within
permissible limits.
14
The number of examined workers, and microwave ovens in each cafeteria
are given in table 3.1.
Table 3.1: Number of examined workers and microwave ovens in
different cafeterias in Palestine
Cafeterias in Higher Educational
Institutions
Number of examined
Workers
Number of
microwave ovens
An-Najah National University
18
10
The Arab American University
7
3
Hisham Hijawi College
1
1
Palestine Technical University
2
1
3.2 Stages of the Study
Stages that have been adopted in this study are as follows:
1. Visiting the higher educational institutions and taking the permission
for carrying out examination on workers and microwave ovens.
2. Informing the workers about the nature of the study and taking their
approval for doing the measurements on them.
3. Collecting the necessary information of the study concerning
information about ovens such as dates of manufacturing, country of
origin, operating power, age, number of users, duration of use, the
location of the oven regarding the public and physical condition.
Information about workers age, and employment duration.
4. Measuring the light intensity of the cafeterias during the period
between 8:00 and 2:00.
5. Measuring the sound pressure levels in the cafeterias during the
period between 8:00 and 2:00.
15
6. Measuring the power flux density of the electromagnetic radiation in
the cafeterias.
7. Measuring several health parameters as:
a. Heart pulse rate
b. Blood oxygen saturation
c. Tympanic temperature
d. Arterial blood pressure (Systolic and Diastolic)
3.3 Timetable of the Study
This study was conducted during December, 2013 and January, 2014. The
measurements of heart pulse rate, blood oxygen saturation, tympanic
temperature, and blood pressure (Systolic and Diastolic) of the sample
were carried out three times before the workers start at 8:00-8:30 am. The
measurements were repeated three times after the workers finish using
microwave ovens at 2:00-2:30 pm. The averages of the measured values
were recorded.
3.4 Standard Exposure Radiation
Measurements of electromagnetic radiation from different ovens will be
compared with the electromagnetic field levels from American National
Standard Institute (ANSI), which recommends exposure limit of 5104
mW/m² at 1500-100000 MHz frequency range.
The standard levels for workers exposure to power flux density provided
by American National Standard Institute are given in table 3.2.
16
Table 3.2: Reference levels for power flux density exposure (exposure
levels in mW/cm2) (American National Standard Institute, 1982)
Frequency range (MHz)
Power flux density (mW/m2)104
0.3-3
100
3-30
900/f2
30-300
1.0
300-1500
f/300
1500-100000*
5.0
*: This is the frequency range of microwave oven which is 2.45 GHz
corresponding to 12.6 cm microwaves.
The reference levels for general public exposure to time varying electric
and magnetic fields with exposure time 6 min are given in table 3.3.
Table 3.3: Reference levels for general public exposure to time varying
electric and magnetic fields for 6 min provided by ICNIRP (Vecchia,
2007)
Exposure
category
Frequency range
E-field
strength
(V/m)
H-field
strength
(A/m)
power
density Seq
(mW/m2) 103
Occupational
100KHz-1 MHz
614
1.63/f
-
1MHz-10MHz
614/f
1.63/f
1000/f 2
10MHz-400MHz
61.4
0.163
10
400MHz-2GHz
3.07×f 0.5
0.00814×f 0.5
f /40
2GHz-300GHz
137
0.364
50
General public
100 KHz-15KHz
86.8
4.86
-
150KHz-1MHz
86.8
0.729/f
-
1MHz-10MHz
86.8/f 0.5
0.729/f
-
10MHz-40MHz
27.4
0.0729
2
400MHz-2GHz
1.37×f 0.5
0.00364×f 0.5
f /200
2GHz-300GHz
61.4
0.163
10
Where f is the frequency in hertz, Seq is the equivalent power flux densities.
The reference values for SAR are given in table 3.4.
17
Table 3.4: Standard values for SAR in Europe and USA (David, 2005)
Whole body
SAR
Spatial peak
SAR
Averaging
time
Averaging
Mass
Europe
0.08 W/kg
2 W/kg
6 min
10 gm
USA
0.08 W/kg
1.6 W/kg
30 min
1 Gm
3.5 Experimental Apparatus
To fulfill the purpose of this study, many tools and devices have been used.
In the following subsections the instruments used will be briefly explained.
3.5.1 Sound Level Meter 2900
Measuring of noise level in the selected cafeterias was obtaining by using
sound level meter. Quest Technologies USA, Model 2900 type 2. It has an
accuracy of ± 0.5 dB at 25 °C. This device gives the reading with precision
of 0.1 dB. Sound level meter was used to make sure that the sound level is
in quite range < 60 dB. Fig. 3.1 shows the sound pressure level meter that
is used (Instruction manual for sound pressure level meter, 1998).
Fig. 3.1: Sound Pressure Level Meter Model 2900 (Instruction Manual for Sound
Pressure Level Meter, 1998)
18
3.5.2 Lux Hitester
Hioki 3423 lux Hitester Digital illumination meter is used to measure the
light intensity. This instrument is suited for a wide range of application. It
measures a broad range of luminosities; from the low light provided by
induction lighting up to a maximum intensity of 199,900 lux. This
instrument was used in this study to measure the intensity of light in
different regions in the selected cafeterias. Fig. 3.2 shows Hioki 3423 lux
Hitester Digital illumination meter.
Fig. 3.2 Hioki 3423 Lux Hitester Digital Illumination Meter (Instruction Manual for
Lux Hitester, Japan, 2006)
3.5.3 Acoustimeter RF Meter
Acoustimeter AM-10 RF Meter is a dedicated radio frequency (RF)
radiation meter. Frequency response is 200 MHz-8 GHz. This meter is
used to measure radiation from different sources. It measures RF radiation
from 200 MHz up to 8 GHz with accuracy ±3 dB, and can measure average
exposure levels from 1 to 100,000 microwatts per square meter (μW/m2).
The peak exposure levels from 0.02 to 6.00 volts per meter (V/m). Power
flux density in this study was measured by using this device. Acoustimeter
RF meter is shown in Fig. 3.3.
19
Fig. 3.3 Acoustimeter RF Meter (Instruction Manual for Spectran RF 6080, Aronia AG
Germany, 2007)
3.5.4 Micro Life Blood Pressure Meter
Automatic Blood Pressure Monitor (micro life AG, Modno. BP 2BHO). Its
measuring range is 30-280 mm-Hg, with accuracy ± 0.02 mm-Hg, and ±
2% for reading heart pulse rate with operating temperature range of +10 °C
to +40 °C. Arterial blood pressure systolic, diastolic and heart pulse rate
values in this study were determined by using micro life blood pressure
meter. Micro life blood pressure meter is shown in Fig. 3.4 below
(Instructions manual for Automatic Digital Electronic Wrist Blood
Pressure, 1998a).
20
Fig. 3.4 Micro Life Blood Pressure Meter (Instructions Manual for Automatic Digital
Electronic Wrist Blood Pressure, 1998a)
3.5.5 Pulse Oximeter
Pulse Oximeter LM-800.Finger Oximeter with accuracy ± 1% is used to
measure the blood oxygen saturation of each worker in the cafeterias. Pulse
oximeter is shown in figure 3.5 (Instructions Manual for Pulse Oximeter,
2012).
Fig. 3.5 Pulse Oximeter (Instructions manual for pulse oximeter, 2012)
21
3.5.6 TempScan Thermometer
The GT-302/GT-302-1 ear thermometer instrument is used to measure
human body temperature through the tympanic temperature of the ear. The
display temperature range is 32.0 to 42.9 °C with an accuracy range of
±0.01°C.The temperature values of this study were detected by using
Temperature Scan thermometer which is shown in Fig. 3.6.
Fig. 3.6: TempScan Thermometer (Instructions Manual for Digital Ear Thermometer,
China, 2011)
3.5.7 Scan Probe
Scan Probe is a tool used to detect the presence of an electromagnetic field.
It provides audio and visual indication of relative field strength. It is a one
axis sensor. It is powered by 2 AAA batteries. Scan Probe offers a green,
red, and yellow 5-LED light and audible tone which changes pitch with
field strength. Scan Probe is shown in Fig. 3.7.
22
Fig. 3.7 Scan Probe (Instruction Manual for Scan Probe, China, 2006)
3.6 Statistical Analysis
Microsoft Excel and Statistical Package for Social Science (SPSS)
programs were used to analyze the gathered data, to find the relationship
between the dependent and independent variables. Measurements were
analyzed statistically as the following: The probability (P) and Pearson
correlation factor (R) were used to measure the strength correlation
between radiation leakage from microwave ovens and the dependent
variables, before and after exposure to this radiation. The P values ranged
from zero to one. Values with P < 0.05 were considered statistically
significant.
Pearson correlation coefficient (R) reflects the degree of linear relationship
between two variables. It ranges from -1 to +1. There is an increasing
linear relationship when R value is +1 which is called a perfect positive.
While a decreasing linear relationship occurs when R value is -1. When R
value is equal to zero, this indicates that there is no correlation exists
23
between the studied variables. The (R) values ranged from zero to one as
follows:
a. 0.00 ≤ |R| ≤ 0.35, weak correlation
b. 0.36 ≤ |R| ≤ 0.67, moderate correlation
c. 0.68 ≤ |R| ≤ 0.90, strong correlation
d. 0.90 |R| ≤ 1.0, very strong correlation (Richard, 1990)
24
Chapter Four
Results
Experimental measurements which were conducted to achieve the purpose
of this study will be discussed in this chapter. Measurements of light
intensity and sound pressure levels will be explained in Sec 4.1. Measuring
of Radiation leakage from microwave ovens with distance, operating
power, and duration of use will be explained in Sec 4.2. Electric fields,
magnetic fields, and SAR are calculated and presented in Sec 4.3.
Measurements of health effects of microwave radiation will be discussed in
Sec 4.4.
4.1 Light Intensity and Sound Pressure Levels Results
The light intensity level and sound pressure level were recorded many
times between 8:00 am to 2:00 pm. Light intensity measurements were
carried out by using Lux Hitester. Sound pressure meter was used to
measure the sound level in the cafeterias. It has been found that the light
intensity level was between 200-600 Lux. While the sound pressure level
was ranging from 50-60 dB which is considered to be within permissible
limits. Average values of light intensity and sound pressure levels in the
universities' cafeterias are given in table 4.1. It has been found that there
are effects from sound level, light intensity and other electromagnetic
waves (Abdelraziq, et al, 2000), (Qamhieh, et al, 2000), (Abdelraziq, et al,
2003), (Abdelraziq, et al, 2003), (Sadeq Rowaida, 2010), (Sadeq, et al,
2012), (Abo-Ras Hadeel, 2012), (Al- Faqeeh Iman, 2013), (Al-Sheikh
Ibrahim Dana, 2012), (Al-Sheikh Mohammad Noorhan, 2013), (Dana, et
25
al, 2013), (Noorhan, et al, 2013), (Abu-Sabha Omar, 2014), (Suliman
Mohammed, 2014), (Thaher Reham, 2014), (Darawshe Muna, 2014).
Table 4.1: Average values of light intensity level and sound pressure
level in the cafeterias of the selected higher educational institutions
Higher Educational
Institutions Cafeterias
Light intensity level
(Lux)
Sound pressure
level (dB)
An Najah National
University Cafeterias
424.93
54.03
The Arab American
University Cafeterias
417.05
54.19
Hisham Hijawi Cafeterias
552.47
52.01
Palestine Technical
University Cafeterias
200.51
52.73
4.2 Radiation Leakage from Microwave Ovens
Radiation leakage from microwave ovens was measured by using
Acoustimeter RF Meter and Scan Probe. The scan Probe is used to cover
all possible radiation points of the oven. RF meter is then used to measure
radiation leakage from the ovens. Measurement of ovens leakage was
performed by inserting a glass of water inside the oven and operating the
oven for 10 min. The average value of radiation leakage at a distance of 5
cm from microwave oven was measured to be (46.126 mW/m2) which is
small compared to the standard value. The standard value set in table 3.2
for occupational use of microwave ovens is 5 104 mW/m2.
Average values of the radiation leakage from the microwave ovens that
have been measured in the different cafeterias of this study are shown in
Fig. 4.1.
26
Fig. 4.1 Average values of the measured radiation leakage level at 5 cm distance from
microwave ovens in the cafeterias under study.
4.2.1 Radiation Leakage with Distance
Radiation leakage from the microwave ovens is measured at different
distances ranging between 0-3 m. A decrease in radiation leakage was
clearly observed as moving away from the ovens. The radiation leakage as
a function of distance is shown in Fig. 4.2.
Fig. 4.2 Radiation leakage from microwave ovens as a function of distance
0
10
20
30
40
50
60
70
NU AU HC PU
Average Radiation
Leakage (mW/m2)
Higher education institutions Cafeterias
0
10
20
30
40
50
60
70
0 0.5 1 1.5 2 2.5 3 3.5
Radiation Leakage(mW/m2)
Distance (m)
27
It has been observed from Fig. 4.2 that there is an exponential decrease of
radiation leakage with distance from the ovens.
4.2.2 Radiation Leakage with Operating Power
The tested ovens were of different types with operating power between
700W to 1600W. A sample of 15 ovens was divided into two groups
according to the oven's operating power. The first group includes ovens
with operating power from 750 to 900 W. The second group includes
ovens with operating power from 1000 to 1600 W.
Radiation leakage from ovens versus operating power is shown in Fig. 4.3.
Fig. 4.3 Average values of radiation leakage against ovens operating power
It has been noticed that ovens with operating power from 1000 to 1600 W
have less radiation leakage than ovens with operating power from 750 to
900 W. This relation may be explained that the manufactures take into their
consideration the safety factor of higher operating power ovens more than
lower operating power ones.
0
10
20
30
40
50
60
750 - 900 (W) 1000 -1600 (W)
Radiation Leakage
(mW/m )
Operating power (W)
28
4.2.3 Radiation Leakage with Duration of Use
The tested ovens are with different duration of use ranging from 5 months
to 10 years. Ovens were classified according to duration of use. It has been
found that 6 ovens have 5 months to 5 years of use range and 9 ovens have
6 to 10 years of duration of use. Radiation leakage from ovens as a
function of duration of use is shown in Fig. 4.4.
Fig. 4.4 Average radiation leakage from microwave ovens as a function of duration of
use
It has been noticed from Fig. 4.4 that the radiation leakage from
microwave ovens increases as their duration of use increases.
4.3 Calculation of Specific Absorption Rate (SAR)
The electric fields (E), magnetic fields (H), and magnetic flux density (B)
have been calculated respectively as shown in table 4.2.
0
5
10
15
20
25
30
35
40
45
1 -5 (Y) 5-10 (Y)
Radiation Leakage (mW/m²)
Duration of use (Year)
29
Table 4.2: Average values of power flux density, electric field,
magnetic field strength, magnetic flux density in the selected
cafeterias.
B(G)
10-8
(Calculated)
H(A/m)
10-3
(Calculated)
E(V/m)
(Calculated)
S(mW/m2)
(Measured)
Cafeterias of
higher
education
institutions
1.66
13.20
5
65.67
NU
1.59
12.63
4.76
60.14
AU
1.15
9.14
3.45
31.50
HC
1.07
8.49
3.20
27.20
PU
The calculated values of electric field and magnetic field strength are small
compared with the standard values set in table 3.3 which equals 137 V/m
for electric field and 0.364 A/m for magnetic field strength.
The calculated values in table 4.2 will be used to calculate specific
absorption rate (SAR) for specific tissues such as the skin, brain, muscle,
and the eye sclera of the workers. SAR values were calculated according to
mass density ( and the tissue conductivity ( values which are given in
table 4.3 (Angelone, et al, 2004). The SAR calculation was done using the
equation
SAR = 
30
Table 4.3: Calculated SAR values for some tissues of workers in the
cafeterias used in this study (Angelone, et al, 2004).
4.4 Measurements of Health Parameters
The study sample includes 28 workers distributed in the tested cafeterias.
The worker's ages were between 20 to 55 years. All the workers are males.
The sample was divided according to the age into two groups. The first
group (G1) included 23 workers whose ages are between 20 to 34 years.
The second group (G2) contains 5 workers whose ages are between 35 to
55 years. The health parameters are heart pulse rate, blood oxygen
saturation, tympanic temperature, arterial blood pressure systolic and
diastolic. The workers' health parameters were measured three times before
and three times after exposure to microwave radiation by using several
instruments. The average values of the workers' health parameters are
given in table 4.4.
SARK
(W/Kg)
10-3
SARH
(W/Kg)
10-3
SARA
(W/Kg)
10-3
SARN
(W/Kg)
10-3
(Kg/m3)
(Ω-1m-1)
Tissue
8.13
9.41
18
19.63
1100
0.872
Skin
7.67
8.88
16.95
18.51
1030
0.77
Brain
9.35
10.83
20.67
22.57
1040
0.948
Muscle
10.94
12.66
24.18
26.40
1100
1.173
Eye
sclera
31
Table 4.4: Average values of heart pulse rate, oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic, before (b) and after (a) exposure to microwave radiation for
the tested workers.
Normal
Range
Average values
(a)
Average values
(b)
Health parameter
60-100a
81
78
HPR(beats/min)
95%-100%b
98
98
SPO2%
33.6-37.6c
33.6
33.0
T()
120d
132
134
SBP(mmHg)
80d
81
78
DBP(mmHg)
a: (NIH, 2011).
b: (WHO, 2011).
c: (Elizabeth and Karen, 2009).
d: (NIH, 2003).
Average values of heart pulse rate (HPR), blood oxygen saturation
(SPO2%), tympanic temperature, and arterial blood pressure systolic (SBP)
and diastolic (DBP), before and after exposures to microwave radiation are
presented in table 4.5 for the two age groups G1 and G2.
32
Table 4.5: Average values of heart pulse rate, blood oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic, before (b) and after (a) exposure to microwave radiation for
groups G1 and G2.
Variables
G1 (20-34)y
G2 (35-55)y
HPR(beats/min) (b)
78
77
HPR(beats/min) (a)
83
76
SPO2% (b)
98
98
SPO2% (a)
98
98
T( (b)
34.0
32.9
T( (a)
33.6
33.5
SBP (mmHg) (b)
134
130
SBP (mmHg) (a)
131
139
DBP (mmHg) (b)
79
85
DBP (mmHg) (a)
80
85
The Percentage change of the average values of heart pulse rate, blood
oxygen saturation, tympanic temperature, and arterial blood pressure
(systolic and diastolic) for the workers age groups before and after
exposure to microwave radiation have been calculated and listed in table
4.6.
Table 4.6: Percentage change of the average values of heart pulse rate,
blood oxygen saturation, tympanic temperature, and arterial blood
pressure systolic and diastolic for workers age groups G1 and G2.
Variables
G1 (20-34)y (%)
G2 (35-55)y (%)
HPR(beats/min)
5.58
1.04
SPO2%
0.35
0.00
T(
2.0
1.7
SBP(mmHg)
2.46
6.29
DBP(mmHg)
1.77
0.23
33
Minimum, maximum, mean, and standard deviation values, before and
after exposure to microwave radiation for both age groups, are presented in
tables 4.7 and 4.8.
Table 4.7: Minimum (Min.), maximum (Max.), mean, and standard
deviation values, before (b) and after (a) exposure to microwave
radiation for group G1 (20-34) years old.
Variables
Min.
Max.
Mean
S.D.
HPR(beats/min) (b)
61
97
78
10.0
HPR(beats/min) (a)
70
106
83
9.3
SPO2% (b)
97
99
98
0.9
SPO2% (a)
96
99
98
0.9
T( (b)
32.1
34.8
33.0
0.7
T( (a)
32.7
34.6
33.6
0.5
SBP (mmHg) (b)
108
171
134
15.0
SBP (mmHg) (a)
103
163
131
14.8
DBP (mmHg) (b)
54
94
79
10.7
DBP (mmHg) (a)
39
98
80
14.3
Table 4.8: Minimum (Min.), maximum (Max.), mean, and standard
deviation values, before (b) and after (a) exposure to microwave
radiation for group G2 (35-55) years old.
Variables
Min.
Max.
Mean
S.D.
HPR(Beats/min) (b)
66
89
77
9.7
HPR(Beats/min) (a)
67
90
76
9.0
SPO2% (b)
97
99
98
0.8
SPO2% (a)
97
99
98
0.8
T( (b)
32.4
33.9
32.9
0.6
T( (a)
33.1
33.8
33.5
0.3
SBP (mmHg) (b)
117
142
130
10.8
SBP (mmHg) (a)
122
154
139
14.0
DBP (mmHg) (b)
75
98
85
10.0
DBP (mmHg) (a)
71
102
85
12.0
34
The sample of 28 workers was also classified according to the duration of
employment. Group (GA) involved 21 workers with 5 months to 5 years of
work. Group (GB) contain 7 workers with 6 to 10 years of work. Average
values of heart pulse rate (HPR), blood oxygen saturation (SPO2%),
tympanic temperature, and arterial blood pressure (systolic and diastolic)
before and after exposure to microwave radiation for duration of
employment groups are presented in table 4.9.
Table 4.9: Average values of heart pulse rate, blood oxygen saturation,
tympanic temperature, and arterial blood pressure systolic and
diastolic before (b) and after (a) exposure to microwave radiation for
both groups GA and GB.
Variables
GA (5mos.-5y)
GB (6-10)y
HPR(beats/min) (b)
79
75
HPR(beats/min) (a)
82
79
SPO2% (b)
98
98
SPO2% (a)
98
98
T( (b)
32.8
33.3
T( (a)
33.5
33.7
SBP (mmHg) (b)
131
138
SBP (mmHg) (a)
130
139
DBP (mmHg) (b)
77
83
DBP (mmHg) (a)
80
83
Table 4.10: Percentage change of the average values of heart pulse
rate, blood oxygen saturation, tympanic temperature, and arterial
blood pressure systolic and diastolic for the workers duration of
employment for both groups GA and GB.
Variables
GA(5mos.-5y) (%)
GB (6-10)y (%)
HPR(beats/min)
4.3
5.71
SPO2%
0.34
0.15
T(
2.2
1.2
SBP(mmHg)
0.44
0.21
DBP(mmHg)
3.44
0.00
35
Minimum, maximum, mean and standard deviation values, before and after
exposure to microwave radiation for duration of employment groups, are
presented in tables 4.11 and 4.12.
Table4.11: Minimum (Min.), maximum (Max.), mean, and standard
deviation values before (b) and after (a) exposure to microwave
radiation for group GA (5mos.-5y).
Variables
Min.
Max.
Mean
S.D.
HPR(beats/min) (b)
61
97
79
10.4
HPR(beats/min) (a)
67
106
82
9.9
SPO2% (b)
97
99
98
0.9
SPO2% (a)
96
99
98
0.9
T( (b)
32.1
34.8
32.8
0.6
T( (a)
32.7
34.6
33.5
0.5
SBP (mmHg) (b)
108
157
131
12.4
SBP (mmHg) (a)
103
163
130
15.3
DBP (mmHg) (b)
54
94
77
10.4
DBP (mmHg) (a)
39
102
80
14.6
Table4.12: Minimum (Min.), maximum (Max.), mean, and standard
deviation values before (b) and after (a) exposure to microwave
radiation for group GB (6-10) y.
Variables
Min.
Max.
Mean
S.D.
HPR(beats/min) (b)
63
84
75
7.5
HPR(beats/min) (a)
70
95
79
8.4
SPO2% (b)
97
99
98
1.0
SPO2% (a)
97
99
98
0.7
T( (b)
32.3
34
33.3
0.6
T( (a)
33.2
34.3
33.7
0.4
SBP (mmHg) (b)
117
171
138
19.7
SBP (mmHg) (a)
122
154
139
13.2
DBP (mmHg) (b)
73
93
83
8.9
DBP (mmHg) (a)
61
92
83
11.0
36
4.4.1 Heart Pulse Rate Result
The automatic blood pressure meter was used to measure heart pulse rate
of the workers. Average values of heart pulse rate before and after
exposure to microwave radiation have been calculated and plotted in
Fig. 4.5 for both age groups G1 and G2.
Fig. 4.5 Average values of heart pulse rate of workers before and after exposure to
microwave radiation from microwave ovens of G1 and G2 of groups.
It has been observed that the heart pulse rate for the workers between 20-
34 years age increases after exposure to microwave radiation, while the
average values of heart pulse rate for workers whose age range between
35-55 years decreases after exposure to microwave radiation.
The average values of heart pulse rate of workers before and after exposure
to microwave radiation from microwave ovens of GA and GB groups are
shown in Fig. 4.6.
0
10
20
30
40
50
60
70
80
90
G1 G2
Heart Pulse Rate
(beat/min)
Age (Year)
a
b
37
Fig. 4.6 Average values of heart pulse rate of workers before and after exposure to
microwave radiation of GA and GB groups.
The average values of heart pulse rate for both groups GA and GB increase
after exposure to microwave radiation from microwave ovens.
4.4.2 Blood Oxygen Saturation Result
Pulse Oximeter has been used to measure SPO2% for workers. SPO2%
values have been recorded three times at 8:00 am and three times after 6
hours of work, which is around 2:00 pm. Average values of blood oxygen
saturation of workers before and after exposure to microwave radiation
from microwave ovens are shown in Figs. 4.7 and 4.8.
Fig. 4.7 Average values of blood oxygen saturation of workers before and after
exposure to microwave radiation of G1 and G2 groups.
0
10
20
30
40
50
60
70
80
90
GA GB
Heart Pulse Rate
(beat/min)
Duration of Work (Year)
a b
97.5
97.6
97.7
97.8
97.9
98
98.1
98.2
98.3
98.4
98.5
G1 G2
Blood Oxygen Saturation
Age (Year)
a
b
38
Blood oxygen saturation values decrease after exposure to microwave
radiation for the first age group G1, while there is no change in SPO2%
values for group G2 of workers after exposure to microwave radiation.
Fig. 4.8 Average values of blood oxygen saturation of workers before and after
exposure to microwave radiation of GA and GB of groups.
There is no change in the average values of SPO2% after exposure to
microwave radiation for GA and GB groups of workers.
4.4.3 Tympanic Temperature Results
Temperatures of the workers were measured through their ears by using
TempScan Thermometer. The temperatures of workers were measured
three times before and three times after exposure to microwave radiation
from the microwave ovens. Average values of temperature before and after
exposure to microwave radiation are shown in Figs. 4.9 and 4.10.
0
20
40
60
80
100
120
GA GB
Blood Oxygen Saturation
Duration of Work (Year)
a
b
39
Fig. 4.9 Average values of temperature of workers before and after exposure to
microwave radiation of G1 and G2 of groups.
There is a noticeable increment in temperature values for G1 and G2 of
workers after exposure to microwave radiation
Fig. 4.10 Average values of temperature of workers before and after exposure to
microwave radiation of GA and GB groups.
There is no change in temperature values for both groups GA and GB
groups of workers after exposure to microwave radiation.
32.4
32.6
32.8
33
33.2
33.4
33.6
33.8
G1 G2
Temperature (ᵒC)
Age (Year)
a
b
0
5
10
15
20
25
30
35
40
GA GB
Temperature (ᵒC)
Duration of Work (Year)
a
b
40
4.4.4 Blood Pressure Results
Arterial blood pressures systolic and diastolic were measured by using
micro life blood pressure meter for each worker. The average values
recorded three times at 8:00 am and three times at 2:00 pm after the
workers' exposure to microwave radiation from the microwave ovens.
Average values of systolic and diastolic blood pressure for workers before
and after exposure to microwave radiation of G1 and G2 groups are shown
in Fig. 4.11 and Fig. 4.12.
Fig. 4.11 Average values of systolic blood pressure of workers before and after
exposure to microwave radiation of G1 and G2 groups.
Fig. 4.11 shows an increment in systolic blood pressure values after
exposure to microwave radiation for both age groups G1 and G2.
0
20
40
60
80
100
120
140
160
G1 G2
Systolc Blood Pressure
(mmHg)
Age (Year)
a
b
41
Fig. 4.12 Average values of diastolic blood pressure of workers before and after
exposure to microwave radiation of G1 and G2 groups.
It has been observed that there is no change in the average values of
diastolic blood pressure after exposure to microwave radiation for G1 and
G2 groups.
Average values of systolic and diastolic blood pressure of workers before
and after exposure to microwave radiation of GA and GB groups are shown
in Fig. 4.13 and Fig. 4.14.
Fig. 4.13 Average values of systolic blood pressure of workers before and after
exposure to microwave radiation of GA and GB groups.
0
10
20
30
40
50
60
70
80
90
G1 G2
Diastolic Blood Pressure
(mmHg)
Age (Year)
a
b
0
20
40
60
80
100
120
140
160
GA GB
Systolic Blood Pressure
(mmHg)
Duration of Work ( Year)
a
b
42
No change occurred in the average values of systolic blood pressure after
exposure to microwave radiation for both groups GA and GB.
Fig. 4.14 Average values of diastolic blood pressure of workers before and after
exposure to microwave radiation of6 GA and GB groups.
No change has been noticed in the average values of diastolic blood
pressure for GA and GB groups of workers.
4.5 Data Analysis of Dependent Variables and Radiation Leakage
from Microwave Ovens
The Statistical Package for Social Science (SPSS) program was used to
analyze the collected data. Paired sample tests of dependent variables
which are (heart pulse rate, blood oxygen saturation, tympanic
temperature, systolic and diastolic blood pressure) and radiation leakage as
independent variables were carried out. Comparing between values before
and after exposure to microwave radiation for the tested workers the
correlation coefficient (R) is introduced in table 4.13.
0
10
20
30
40
50
60
70
80
90
GA GB
Diastolic Blood Pressure
(mmHg)
Duration of Work (Year)
a
b
43
Table 4.13: Pearson correlation coefficient between radiation leakage
from microwave ovens and heart pulse rate, blood oxygen saturation,
tympanic temperature, systolic and diastolic blood pressure for all
workers in the cafeterias.
Pearson correlation(R)
Paired samples
0.781
HPR(beats/min)
-0.849
SPO2%
0.800
T(
0.567
SBP(mmHg)
0.694
DBP(mmHg)
44
Chapter Five
Discussion and Conclusion
5.1 Radiation Leakage with Distance and Operating Power
The average value of radiation leakage at a distance 5 cm from microwave
ovens was 46.126 mW/m2. This value is small compared with the standard
value which is set in table 3.2 by American National Standard Institute
which is 5 104 mW/m2. It has been concluded that radiation leakage
decreases exponentially with distance as shown in Fig. 4.2. The
possibilities of radiation leakage from microwave ovens increased with
duration of use. Ovens with 6 to 10 years of use have more radiation
leakage than ovens with 5 months to 5 years of use. Such conclusions have
been supported by other previous studies conducted by Lahham and
Sharabati (Lahham and Sharabati, 2013).
5.2 The Effect of Microwave Radiation on Heart Pulse Rate
This study reveals that the average values of heart pulse rate for the
workers in the tested cafeterias are increase after exposure to microwave
radiation from microwave ovens. For example, the average value before
exposure was 78 beat/min and after exposure, it increased to 81 beat/min.
The strength of the result is good as it can be understood from the Pearson
correlation factor (R = 0.781) between radiation leakage and heart pulse
rate. The difference between average values of heart pulse rate before and
after exposure to MWR is 3 beat/min. Despite the increase in HPR after
exposure to microwave radiation, it remains within the normal range of
human body which is from 60-100 beat/min (NIH, 2011).
45
5.3 The Effect of Microwave Radiation on Blood Oxygen Saturation
The results of blood oxygen saturation showed no change occurred in
SPO2% values after exposure to microwave radiation. The average value of
SPO2% before exposure was 98 and after exposure the value does not
change. The Pearson correlation factor is 0.849 which shows a strong
correlation between radiation leakage and blood oxygen saturation. The
average values of SPO2% is within the normal range which is 95%-100%
as set by the world health organization in 2011 (WHO, 2011).
5.4 The Effect of Microwave Radiation on Tympanic Temperature
The average values of tympanic temperature for the workers in the tested
cafeterias increase after exposure to microwave radiation. The average
value of workers temperature was 33 and it increased to 33.6 after
exposure to microwave radiation. The statistical results showed that the
Pearson correlation coefficient between the radiation leakage and tympanic
temperature equals 0.830. This indicates that there is a strong correlation
between the dependent variable (Tympanic temperature) and the
independent variable (Radiation Leakage). The standard value of tympanic
temperature for humans is (33.6-37.6 which was concluded in 2009 by
Elizabeth and Karen (Elizabeth and Karen, 2009).
5.5 The Effect of Microwave Radiation on Systolic and Diastolic Blood
Pressure
The results of systolic blood pressure are decreased after exposure to
microwave radiation. The average value before exposure was 134 mmHg
and after exposure it is decreased to 132 mmHg, while the average value of
46
diastolic blood pressure increases after exposure to microwave radiation
from microwave ovens. The average value of DBP was 78 mmHg and it
increase to 81 mmHg. The statistical analysis for SBP and DBP as
dependent variables and radiation leakage from microwave ovens as an
independent variable showed that the Pearson coefficient for SBP and DBP
respectively is (R = 0.567, R = 0.694). The standard value of arterial blood
pressure as given in table 5.1 set by National Institute of Health is 120
mmHg for SBP and 80 mmHg for DBP (NIH, 2003).
The normal range of heart pulse rate, blood oxygen saturation, tympanic
temperature, systolic and diastolic blood pressure is given in table 5.1.
Table 5.1: The normal range recommended standards of heart pulse
rate, blood oxygen saturation, tympanic temperature, systolic and
diastolic blood pressure.
Variables
Normal range
HPR(beat/min)
60-100a
SPO2%
95%-100%b
T(
33.6-37.6c
SBP(mmHg)
120d
DBP(mmHg)
80d
a: (NIH, 2011).
b: (WHO, 2011).
c: (Elizabeth and Karen, 2009).
d: (NIH, 2003).
47
In this study a small change in the average values of the studied parameters
has been observed. The normal range of the measured health parameter
was set in table 5.1. The changes in the studied variables remain in the
normal range of human beings. The average value of radiation leakage was
small compared with the standard values set by the American National
Standard Institute. In Conclusion, there are no serious health effects of
microwave radiation from microwave ovens on the workers of the
cafeterias of the higher education institutions examined in this research.
This conclusion enhances the results of the previous studies. For instance,
Matthes' study in 1992 showed that exposure to microwave radiation
during microwave cooking has no risk health effects (Matthes, 1992).
Alhekail in his study observed that the health effects due to exposure to
microwave radiation from microwave ovens are not expected to occur
(Alhekail, 2001). Mohammads' study in 2011 summarized that -thermal
health effects form the only result for the exposure to microwave radiation
from microwave ovens because the measured radiation leakage is small
compared with the level that may harm people (Mohammad, et al, 2011).
48
Chapter Six
Recommendations
In view of the outcome of this study as well as the conclusions of previous
ones, the following recommendations can be made to avoid any dangerous
effects that may occur from exposure to radiation from microwave ovens.
1. Informing workers about the importance of following the
instructions manuals that come with microwave ovens.
2. Keeping a distance of more than 30 cm when using microwave
ovens due to our results shown in Fig. 4.2.
3. Performing periodic test on the workers to determine any health
effects that may occur.
4. Further studies should be done to determine the impact of radiation
leakage on people who use microwave ovens for very long periods
such as in main restaurants.
49
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     
          
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
Conference Paper
Full-text available
Abstract In this research, biodiesel samples of different percentages of blend biodiesel (Palestinian biodiesel prepared from waste oil) and petro-diesel were studied. The density, refractive index, flash point and viscosity of the samples were measured. The flash points were measured as a function of percentage of biodiesel, the results emphasized that the flash points increase as the percentage of biodiesel increases in the sample. Two equations were proposed to obtain more suitable prediction of the flash point. The values of flash points of biodiesel were compared with the standard value of flash point of biodiesel. The comparison shows that samples contain more than 40% biodiesel coincide with standard values. The values of kinematic viscosity of biodiesel were compared with the Palestinian standard value of biodiesel. The comparison shows that samples contain less than 72% biodiesel coincide with standard value. Taking into consideration results of kinematic viscosity and flash point one can suggest percentage 71% of biodiesel and 29% petro-diesel as the best percentage that the two materials can be mixed and the flash point 115.3 ºC according the Palestinian standards.
Thesis
Full-text available
Abstract In this research, biodiesel samples of different percentages of blend biodiesel (Palestinian biodiesel prepared from waste oil) and petro-diesel were studied. The density, refractive index, flash point and viscosity of the samples were measured. The flash points were measured as a function of percentage of biodiesel, the results emphasized that the flash points increase as the percentage of biodiesel increases in the sample. Two equations were proposed to obtain more suitable prediction of the flash point. The values of flash points of biodiesel were compared with the standard value of flash point of biodiesel. The comparison shows that samples contain more than 40% biodiesel coincide with standard values. The values of kinematic viscosity of biodiesel were compared with the Palestinian standard value of biodiesel. The comparison shows that samples contain less than 72% biodiesel coincide with standard value. Taking into consideration results of kinematic viscosity and flash point one can suggest percentage 71% of biodiesel and 29% petro-diesel as the best percentage that the two materials can be mixed and the flash point 115.3 ºC according the Palestinian standards.
Thesis
Full-text available
Abstract This study concerns about the effects of Electromagnetic radiation from antennas on arterial blood pressure (systolic (SBP), diastolic (DBP)), heart pulse rate (HPR), blood oxygen saturation (SPO2%) of children in schools. The sample consists of 273 children of both genders (91 female, 182 male), classified into two groups; 10-12 years and 13-16 years. The sample was taken from three different schools in Nablus area. The measured power flux density in schools was 1862µw/m2, 353.166µw/m2 and 18.278µw/m2. Measurements of blood oxygen saturation, heart pulse rate, arterial blood pressure (systolic and diastolic) were taken for the selected sample before and after the exposure to electromagnetic radiation from antennas. Positive correlation (Pearson Correlation Coefficient) was found for all measured variables. The statistical results showed that Pearson correlation coefficient (R) between the dependent variables (SBP, DBP, HPR, SPO2%) before and after the exposure to electromagnetic radiations from antennas is strong and the Probability (P) is < 0.05. This study shows that there is a significant shift of the measured mean values of arterial blood pressure (systolic and diastolic), heart pulse rate, and blood oxygen saturation of the children due to exposure of electromagnetic radiation from antennas within the normal ranges.
Thesis
Full-text available
This study focuses on the effect of electromagnetic radiation (EMR) emitted by cell phone towers on human tympanic temperature (T), blood oxygen saturation (SPO2%), heart pulse rate (HPR), systolic blood pressure (SBP) and diastolic blood pressure (DBP). The sample is 136 employees of both genders (56 female, 80 male), with mean age 40 Yrs., and the mean duration of employment 14 Yrs., were randomly chosen as a sample to reach the desired objective. This sample was taken from Nablus and Jenin municipalities, which are 70 m and 50 m from cell phone towers, respectively. The mean values of the measured power flux density were 52.58 µW/m2 and 31.76 µW/m2 in Nablus and Jenin municipalities, respectively. The electric field and the magnetic field values were calculated from the measured power flux density, which were less than the standard levels for exposure to EMR of cell phone towers. The measurements of tympanic temperature, blood oxygen saturation, heart pulse rate and arterial blood pressure (systolic and diastolic) of the selected employees were measured before and after exposure to signals of cell phone towers. This study shows that the health effects of signals of cell phone towers depend on the power flux density. The statistical results showed that Pearson correlation coefficient (R) between power flux density and the dependent variables are varying from 0.294 to 0.657, and the probabilities (P) are < 0.05 for all health factors.
Thesis
Full-text available
Abstract In this study we have measured the effect of light intensity levels on the systolic and diastolic blood pressure, blood oxygen saturation, heart pulse rate and tympanic temperature of the employees of three pharmaceutical companies in Ramallah and Al-Bireh district. The employees were chosen to represent the population of the study. The companies were: Birzeit pharmaceutical company-Ramallah branch (BZPR), Dar Alshifa pharmaceutical company (DA), and Birzeit pharmaceutical company-Birzeit branch (BZPB). The sample of the study consisted of 219 employees distributed over the three companies. The parameters were measured before and after the employees work day. The results showed that there is a relation between light intensity levels and all the health parameters. The results of measurements of systolic and diastolic blood pressure show that they are increasing with increasing light intensity levels. The values of Sig P-values were found to be 0.000 and 0.023 for systolic and diastolic blood pressure respectively, while the results of SPO2% show that they decrease with increasing light intensity levels, with Sig P-value was calculated to be 0.000. The tympanic temperature increases when light intensity level increases, (Sig P-value = 0.002). However all changes were in normal range of the recommended standards.
Conference Paper
Abstract This study concerns about the effects of Electromagnetic radiation from antennas on blood oxygen saturation (SPO2%), heart pulse rate (HR), arterial blood pressure (systolic (SBP), diastolic (DBP)) of children’s schools. The sample consists of 273 students of both genders (91 female, 182 male), classified into two groups; 10-12 years and 13-16 years. The sample was taken from three different schools in Nablus area. The measured power flux density in the first school was 1.862mw/m2 and 353.166µw/m2 in the second school and 18.278µw/m2 in the third one. Measurements of blood oxygen saturation, heart pulse rate, arterial blood pressure (systolic and diastolic) were taken for the selected sample before and an after exposure to Electromagnetic radiation from antennas. Positive correlation (Pearson Correlation Coefficient) was found for all measured variables. The statistical results showed that Pearson correlation coefficient (R) between the dependent variables (SPO2%, HR, SBP, DBP) before and after the exposure to electromagnetic radiations from antennas is strong and the Probability (P) is < 0.05. This study shows that there is a significant shift of the measured mean values of blood oxygen saturation, heart pulse rate, arterial blood pressure (systolic and diastolic) of the children due to exposure of electromagnetic radiation from antennas.
Conference Paper
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Abstract This study aims to investigate the effect of exposing to extremely low frequency electromagnetic radiation from high voltage transformers (160 KVA and 250 KVA) on students. The sample of this study was 142 students including 69 males and 73 females, with ages (16-18 years) and (9-11 years). This research was carried out on five schools in Hebron District. Measurements were taken for student's tympanic temperature, blood oxygen saturation, heart pulse rate, and arterial blood pressure (diastolic and systolic). The results showed that the measured values of power flux density were within slight concern limit. The effect of EMR on students health were explained as follows, there was increasing in tympanic temperature, heart pulse rate, arterial blood pressure (systolic and diastolic), on the other hand the blood oxygen saturation was decreased.
Article
Full-text available
This study aims to investigate the effect of exposing to extremely low frequency electromagnetic radiation from high voltage transformers (160 KVA and 250 KVA) on students. The sample of this study was 142 students including 69 males and 73 females, with ages (16-18 years) and (9-11 years). This research was carried out on five schools in Hebron District. Measurements were taken for student's tympanic temperature, blood oxygen saturation, heart pulse rate, and arterial blood pressure (diastolic and systolic). The results showed that the measured values of power flux density were within slight concern limit. The effect of EMR on students health were explained as follows, there was increasing in tympanic temperature, heart pulse rate, arterial blood pressure (systolic and diastolic), on the other hand the blood oxygen saturation was decreased.
Article
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This paper presents the main results obtained in a general study of noise pollution in the city of Nablus in Palestine. The equivalent noise level values (Leq) were measured and tabulated for 50 locations spread over the area of the city. The obtained result of noise level of the 50 Leq values is in average 68.0 dB(A). It has been fouad that the Leq values for 58% of the selected locations are exceeding 65.0 dB(A). This result is obviously higher than the adopted international standards. Accordingly, the area of Nablus is considered an unacceptable living area. Hence, its buildings, streets and factories require severe reconstruction and modification plans. In addition, there should be adequate updated plans for setting up community noise surveys and ordinances.
Article
Full-text available
Abstract This study aims to investigate the effect of exposing to extremely low frequency electromagnetic radiation from high voltage transformers (160 KVA and 250 KVA) on students. The sample of this study was 142 students including 69 males and 73 females, with ages (16-18 years) and (9-11 years). This research was carried out on five schools in Hebron District. Measurements were taken for student's tympanic temperature, blood oxygen saturation, heart pulse rate, and arterial blood pressure (diastolic and systolic). The results showed that the measured values of power flux density were within slight concern limit. The effect of EMR on students health were explained as follows, there was increasing in tympanic temperature, heart pulse rate, arterial blood pressure (systolic and diastolic), on the other hand the blood oxygen saturation was decreased.
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Abstract: The dynamic shear viscosity coefficients of the binary liquid mixture carbon tetrachloride and coconut oil for different temperatures and concentrations are measured using digital viscometer with UL adapter. Shear viscosity anomaly is clearly observed near the critical temperature Tc = 22.2 ℃ and the critical concentration xc = 0.732 by weight of carbon tetrachloride. Debye parameter L (the intermolecular force range) was calculated using a light scattering formula to be L = 5.5 Å. Mode Coupling Theory (MCT) of the dynamic shear viscosity is used to fit our experimental data above the critical temperature in the range 0.05 ≤ T-Tc ≤ 8 ℃. It is found that the noncritical part of the dynamic shear viscosity (background viscosity) η0 = 2.59 cP and the Debye momentum cutoff (the upper cutoff wave number) qD = 0.126 Å-1. The MCT universal constant A is measured to be A = 0.054 which is consistent with the theoretical value.
Thesis
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Abstract The amount of radiation leakage, the electric field, magnetic field and the specific absorption rate (SAR) were investigated from 115 microwave ovens in domestic use in Palestine. The power density of radiation leakage from microwave ovens was measured using instruments. The age of ovens were between 1 month and 13 years old including 14 ovens with unknown age, with operating power ranging from 700 W to 1350 W of different types, manufacturers, and models. The power density of radiation from ovens was measured at different distances at the height of center of door screen. Electric field, Magnetic field and SAR were calculated at distances 5 cm and 20 cm from ovens. These values were much less than the recommended Electromagnetic Field levels (EMF), of International Commission on Non–Ionizing Radiation Protection (ICNIRP) for 2.45 GHz radiofrequency. The power density of radiation leakages from microwave ovens does not depend on the oven age and operating power of ovens.
Thesis
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Abstract This study concerns about the effects of Electromagnetic radiation from antennas on arterial blood pressure (systolic (SBP), diastolic (DBP)), heart pulse rate (HPR), blood oxygen saturation (SPO2%) of children in schools. The sample consists of 273 children of both genders (91 female, 182 male), classified into two groups; 10-12 years and 13-16 years. The sample was taken from three different schools in Nablus area. The measured power flux density in schools was 1862µw/m2, 353.166µw/m2 and 18.278µw/m2. Measurements of blood oxygen saturation, heart pulse rate, arterial blood pressure (systolic and diastolic) were taken for the selected sample before and after the exposure to electromagnetic radiation from antennas. Positive correlation (Pearson Correlation Coefficient) was found for all measured variables. The statistical results showed that Pearson correlation coefficient (R) between the dependent variables (SBP, DBP, HPR, SPO2%) before and after the exposure to electromagnetic radiations from antennas is strong and the Probability (P) is < 0.05. This study shows that there is a significant shift of the measured mean values of arterial blood pressure (systolic and diastolic), heart pulse rate, and blood oxygen saturation of the children due to exposure of electromagnetic radiation from antennas within the normal ranges.
Article
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Abstract The study population consisted of 237 children aged 5-6 years in Jenin city. The arterial blood pressure (systolic and diastolic), heart pulse rate, oxygen saturation in blood and tympanic temperature were measured before and after exposure to light intensity levels for four hours continuously. The light intensity levels were (0 - 60), (400 - 600) and (1320 - 1500) lux. The background light was (400 - 600) lux for all selected schools, which is considered to be normal or accepted light intensity level. Strong positive correlation (Pearson Correlation Coefficient) was found to be R > 0.659 between light intensity levels and all of the arterial blood pressure (systolic and diastolic), heart pulse rate, blood oxygen saturation and tympanic temperature in the selected school. In addition, P-value between the dependent and independent variables was found to be zero. Finally, the study concludes that there is an effect of the light intensity levels on arterial blood pressure (systolic and diastolic), heart pulse rate, oxygen saturation in blood and tympanic temperature of schools’ children. Keywords: Light Intensity, Blood Pressure, Heart Pulse Rate, Oxygen Saturation, Tympanic Temperature.
Article
Abstract This study reports the relationship between occupational noise levels with arterial blood pressure (systolic and diastolic), and heart pulse rate for dentists in their offices chosen randomly in Jenin City. The noise levels measured during operational periods in the chosen dental offices were found to be between 90.5 and 91.7 dB. The arterial blood pressure (systolic and diastolic) and heart pulse rate of doctors were measured before and after exposure to noise for four hours. Positive correlation (Pearson Correlation Coefficient) with noise pollution was found for all measured variables. The mean blood pressure, for examples, has Pearson's Coefficient R = 0.629 for systolic and R = 0.475 for diastolic. In addition, heart pulse rate has a Pearson's Coefficient R = 0.560. This study shows that after four hours of work, there is a significant increase in the mean measured values of blood pressure (systolic and diastolic) and heart pulse rate. The mean of systolic blood pressure, for example, is increased by 4.4 mm-Hg, while the mean of diastolic blood pressure is increased by 3.8 mm-Hg. Finally, the heart pulse rate mean is increased by 3.6 beats/minute. Keywords: Dental Offices, Occupational Noise Levels, Blood Pressure, Heart Pulse Rate.