health effects associated with wireless communication(3)
TRANSCRIPT
Prof. Muthanna Al Omar
5/17/2012 1
Last Update: May 17, 2012
Prof. Muthanna Al Omar
5/17/2012 2
Contents
1. Introduction
2. Electromagnetic fields (EMFs-ELF) vs. RF radiation
6. Sources of RF-EMFs in our daily life.
5. EMFs Spectrum according to its Health Effects
7. Pattern of wireless communication systems
9. Biological effects of wireless communication devices
10. How to estimate the exposure level to RF-EMFs ?
11. What can be done to reduce adverse health hazard?
3. Agencies concerned with RF-EMFs
4. Basic Principles of RF-EMFs
8. Evaluation of Exposure to RF-EMFs
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Acronyms and Abbreviations
Slide No.
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Acronyms and Abbreviations
Electromagnetic Fields
Radio Frequency
Prof. Muthanna Al Omar
ELF
EMF
Extremely low frequency fields
RF
Hz Frequency units (Hertz)
V/m
µT
Volt per meter (Units of electric field strength)
Microtesla (Units of magnetic field strength)
W Watt
AM/FM Amplitude modulation/frequency modulation
Specific Absorption RateSAR
More acronyms and abbreviations are mentioned on slide #9
FCC Federal Communications Commission (USA)
Concern about possible adverse health effects associatedwith mobile phones has been growing , due to thefollowing facts:
The mobile phone is definitely one of the most arrestingdevices in our daily life, being used by everybody everytime, sometimes in a non-sense way .
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1. Introduction
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It is estimated that we live in a world with 100 million timesthe radiation than what our grandparents lived in.
Many individuals are more liableto develop health implications,among them are youngergenerations if they offered themobile phone to use.
If a probability of 1/1.000.000exist in developing illness due to exposure to RF-EMF. Then therewill be a serious health problem among societies.
Prof. Muthanna Al Omar
Our ambient environment is already polluted electromagnetically.
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Mobile phone sales have considerably increased in 2005 ascompared to 1997 and probably it is now almost double,subsequently, number of exposed individual is doubled
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It is worthy to mention that both RF-EMFs and ELF-EMFsare electromagnetic propagation of waves, However, thefollowing differences between the two group exist:
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This presentation will focus on possible effect of RF-EMFsgenerated by mobile phones and its system oftransmission on public health and safety.
2. Electromagnetic fields (EMFs-ELF) vs. RF radiation
ELF-EMFs RF-EMFs
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Communication
Release
Electric sourcesSource
Frequency
Unintentional
3 kHz up to 300 GHz.0 up to about 300 Hz
Unintentional
3 kHz up to 300 GHz.
Intentional
Units V/m and µT
Estimation
mW/cm2
Electric field intensity
Magnetic flux density
Power density
W/kg (tissue)Can not be measured Effect
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3. Agencies concerned with RF-EMFs
World Health Organization (WHO)
Federal Communications Commission (FCC)
Institute of Electrical and Electronics Engineers(IEEE)
National Institute for Occupational Safety and Health(NIOSH)
Occupational Safety and Health Administration(OSHA)
Food and Drug Administration (FDA)
International Commission on Non-Ionizing Radiation Protection (ICNIRP)
American National Standards Institute (ANSI)
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4. Basic Principles of RF-EMFs
An RF field has both an electric and a magnetic component, and is characterized by a wavelength and a frequency.
The wavelength is the distance covered by one complete cycleof the electromagnetic wave, while the frequency is thenumber of electromagnetic waves passing a given point in onesecond.
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5. EMFs Spectrum according to its Health Effects
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6. Sources of RF-EMFs in Daily Life
AM/FM radio and TV stations
Cellular telephones & base stations
Hand-held walkie-talkie & cordless phones
Radar systems
Vehicular communication systems
Internet
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Examples of RF Power Radiated
Exposure Standard for the General Public
The ANSI/IEEE exposure standard for the general public is 1.2 mW/cm2.
The ANSI/IEEE exposure standard for the general public of mobile phones (about 900 MHz)
is 0.57 mW/cm2
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7. Pattern of Wireless Communication Systems
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This illustration shows the pattern of transmission of EMFs signals in an area of a city
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7.1. How Does Mobile Telephony Works?
Radio signals from mobile (#1) is transmitted through the airto the antenna at the closest base station which is thenforwards the signal to the network (#2) to another basestation (#3) and to its end destination (#4).
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7.2. Distribution of Base Stations in an Area
An ideal network may consist of a mesh of hexagonal cells, each with a base station at its center. The cells overlap at the edges to ensure the mobile phone users always remain within range of the base station.
The cell structure of a mobile phone network.
Prof. Muthanna Al Omar
This structure is behind the reason, why the mobile phone is also called :”Cellular Phone”
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8. Evaluation of Exposure to RF-EMFs
SAR: Is a measure of the amount of energy absorbed by the bodywhen using the handset, and is expressed as watt/kg (tissue).
In the United States and Canada for a phone to receive FCCcertification, its maximum SAR level must be 1.6 watts perkilogram.
In Europe, the level is 2 watts per kilogram
Prof. Muthanna Al Omar
When RF-EMFs hit human body, a certain amount of energy isgenerated . This is measured by SAR or Specific Absorption Rate.
SAR varies by handset model and the transmission bands (thesame phone can use multiple bands during a call.
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Rank Model SAR
1 Motorola Bravo 1.59
2 Motorola Droid 2 Global 1.58
3 Sony Ericsson Satio (Idou) 1.56
4 Sony Ericsson Xperia X10 Mini Pro 1.55
4a Kyocera Jax S1300 1.55
6 Motorola i335 1.53
7 Nokia Astound 1.53
8 Motorola Defy 1.52
8a Motorola Grasp 1.52
8b ZTE Salute 1.52
11 LG Rumor 2 1.51
12 Motorola Droid 1.49
12a Sanyo Vero 1.49
12b Motorola Droid 2 1.49
15 HTC Desire 1.48
15a HTC Trophy 1.48
17 LG Chocolate Touch 1.47
17a Motorola Atrix 4G 1.47
19 Kyocera Wild Card M1000 1.46
20 Kyocera X-tc 1.45
20 highest-radiation
cell phones (USA)
Rank Model SAR
1 Samsung Blue Earth 0.196
2 Samsung Infuse 4G 0.2
3 Pantech Breeze III 0.281
4 Samsung Acclaim 0.29
5 Samsung Replenish 0.3
6 Huawei Ideos X5 0.34
6a T-Mobile Sidekick 4G 0.34
8 LG Quantum 0.35
9 Samsung Haven 0.41
9a Samsung Evergreen 0.41
11 Samsung Conquer 4G 0.42
11a Samsung Captivate 0.42
13 Samsung Smiley 0.43
14 HTC Surround 0.439
15 Doro PhoneEasy 410 0.445
16 Pursuit II 0.448
17 Motorola Devour 0.45
17a Motorola i890 0.45
19 Gravity Smart 0.47
20 Kyocera Neo E1100 0.479
20 lowest-radiation
cell phones (USA)
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9. Biological Effects of Wireless Communication Devices.
The most apparent biological effect of RF energy to living cells is due to heating.
Side and front view of human head showing heating effect due to mobile RF energy.
9.1 Thermal Effect
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The body can easily cope with this local temperature change; but other unknown changes may occur, among them are the following:
9.2. Biochemical Effects :
It has been found that, a 50-minute cell-phone call producedsignificantly elevated brain glucose metabolism, which is anormal marker of brain activity.
Prof. Muthanna Al Omar
In fact, the researchers admit that they don’t know what thelong-term consequence of these effects may be?
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Antennas of the mobile phones deliver much of their RF energy to small portions of the user’s head.
9.3. Carcinogenicity
Prof. Muthanna Al Omar
Since the year 2000, a study conducted by 21scientists in 13 countries under the supervisionof WHO, on tumors of the brain, acoustic nerve,and parotid gland, through estimation of the“The odds ratio (OR)”. It was found that:
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No elevated OR was observed ≥10 years of phone use.
As a conclusion; exposure to typical levels of RF-EMF is not linked to carcinogenicity.
9.3. Carcinogenicity-contd.
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Other disorders most often linked with the use of the phone are:
9.4. Other Risks.
Mobile phone radiation may damage The thin lining layers of blood vessels (endothelium) in the brain, thus destroying blood-brain barrier; a vital barrier that stops harmful substances from entering the brain.
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Headache
Attention problems
Asthmatic disorders
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9.5. Electrical interference
Some studies have shown thatwireless devices might interfere withimplanted cardiac pacemakers ifused within eight inches of thepacemaker.Pacemaker users may want to avoidplacing or using a wireless devicethis close to their pacemaker.
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10. How to Estimate the Exposure Level to RF-EMFs ?
2. Distance from the mobile
1. Mobile type and model
3. Time of conversation.
2. Distance from the transmitter.
1. Type of transmitter:e.g. base station, TV broadcasting…etc
3. Duration of Exposure
For Mobile Phone RF Exposure
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Everyone should be aware that exposure to suchradiation may not be completely safe at certain powerlevels and frequencies.
11. What can be done to reduce adverse health hazard?
It is always a good idea to avoid unnecessary radiationexposure whenever possible.
Wireless devices only emit RF energy when you areusing them and, the closer the device is to you, themore energy you will absorb.
Based on the above fact; speakerphone, earpiece orheadset much safer than handset , especially for longduration calls.
Always mind your cumulative call time during the day.
Prof. Muthanna Al Omar
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