PowerPoint Presentation

Protons for Breakfast

Are Mobile Phones Safe?

Week 5

March 2014

In the event of

In the event of a new ice ageIn the event ofIn the event ofThe word radiationThe word radiation meansAnything which radiates on ray-like pathsCould be SoundRadioLightInfra-red lightParticles or waves emitted from the nuclei of atomsNuclear Radiation 3This evening0. The Media!How do mobile phones work?What is the hazard?How do electromagnetic waves interact with matter?SARMicrowave OvensMobile PhoneAre mobile phones safe?

4Media

5

Media

6http://protonsforbreakfast.wordpress.com/2010/03/28/are-mobile-phones-safe-2/

US statistics are available from theNational Institute of Health (NIH) cancer web siteand from theSurveillance, Epidemiology and End Results (SEER) Program web sitewhich has intensively monitored selected populations to garner detailed data sets. Warning: These are BIG web sites and you will not find exactly what you want easily it took me hours to find and extract the data I was looking for i.e. the data which most closely corresponded to that mentioned in the pernicious web site. This is data for the incidence of Leukaemia and Brain Tumours. What do the US data show?Well the data for Brain Tumours and cancers of the central nervous system is shown at head of this piece. The data for Leukemia mainly a cancer of childhood is shown below. Please make up your own mind whether there is an exponential increase in brain tumours or whether there is a change in the ratio of brain tumours to leukaemia or whether there is evidence of a 40% increase in brain tumours.

Sunday, 20 January 2008

It also complements other recent research. A massive study, following 1,656 Belgian teenagers for a year, found most of them used their phones after going to bed. It concluded that those who did this once a week were more than three times and those who used them more often more than five times as likely to be "very tired".

7Mobile phone radiation wrecks your sleepPhone makers own scientists discover that bedtime use can lead to headaches, confusion and depressionBy Geoffrey Lean, Environment Editor

Sunday, 20 January 2008 GRAPHIC: CHARLOTTE BRAUNAGELSOURCE: The EM Academy / IoS Research

Radiation from mobile phones delays and reduces sleep, and causes headaches and confusion, according to a new study.The research, sponsored by the mobile phone companies themselves, shows that using the handsets before bed causes people to take longer to reach the deeper stages of sleep and to spend less time in them, interfering with the body's ability to repair damage suffered during the day.The findings are especially alarming for children and teenagers, most of whom surveys suggest use their phones late at night and who especially need sleep. Their failure to get enough can lead to mood and personality changes, ADHD-like symptoms, depression, lack of concentration and poor academic performance.The study carried out by scientists from the blue-chip Karolinska Institute and Uppsala University in Sweden and from Wayne State University in Michigan, USA is thought to be the most comprehensive of its kind.Published by the Massachusetts Institute of Technology's Progress in Electromagnetics Research Symposium and funded by the Mobile Manufacturers Forum, representing the main handset companies, it has caused serious concern among top sleep experts, one of whom said that there was now "more than sufficient evidence" to show that the radiation "affects deep sleep".The scientists studied 35 men and 36 women aged between 18 and 45. Some were exposed to radiation that exactly mimicked what is received when using mobile phones; others were placed in precisely the same conditions, but given only "sham" exposure, receiving no radiation at all.The people who had received the radiation took longer to enter the first of the deeper stages of sleep, and spent less time in the deepest one. The scientists concluded: "The study indicates that during laboratory exposure to 884 MHz wireless signals components of sleep believed to be important for recovery from daily wear and tear are adversely affected."The embarrassed Mobile Manufacturers Forum played down the results, insisting at apparent variance with this published conclusion that its "results were inconclusive" and that "the researchers did not claim that exposure caused sleep disturbance".But Professor Bengt Arnetz, who led the study, says: "We did find an effect from mobile phones from exposure scenarios that were realistic. This suggests that they have measurable effects on the brain."He believes that the radiation may activate the brain's stress system, "making people more alert and more focused, and decreasing their ability to wind down and fall asleep".About half of the people studied believed themselves to be "electrosensitive", reporting symptoms such as headaches and impaired cognitive function from mobile phone use. But they proved to be unable to tell if they had been exposed to the radiation in the test.This strengthens the conclusion of the study, as it disposes of any suggestion that knowledge of exposure influenced sleeping patterns. Even more significantly, it throws into doubt the relevance of studies the industry relies on to maintain that the radiation has no measurable effects.A series of them most notably a recent highly publicised study at Essex University have similarly found that people claiming to be electrosensitive could not distinguish when the radiation was turned on in laboratory conditions, suggesting that they were not affected.Critics have attacked the studies' methodology, but the new findings deal them a serious blow. For they show that the radiation did have an effect, even though people could not tell when they were exposed.It also complements other recent research. A massive study, following 1,656 Belgian teenagers for a year, found most of them used their phones after going to bed. It concluded that those who did this once a week were more than three times and those who used them more often more than five times as likely to be "very tired".Dr Chris Idzikowski, the director of the Edinburgh Sleep Centre, says: "There is now more than sufficient evidence, from a large number of reputable investigators who are finding that mobile phone exposure an hour before sleep adversely affects deep sleep."Dr William Kohler of the Florida Sleep Institute added: "Anything that disrupts the integrity of your sleep will potentially have adverse consequences in functioning during the day, such as grouchiness, difficulty concentrating, and in children hyperactivity and behaviour problems."David Schick, the chief executive of Exradia, which manufactures protective devices against the radiation, called on ministers to conduct "a formal public inquiry" into the effects of mobile phones.

1. How do mobile phones work?

8Magic?Any sufficiently advanced technology is indistinguishable from magic

Arthur C. Clarke

9Not magicMobile Phones are radio phonesOperating at microwave frequenciesHandset power minimised by having a network of local transmitters and receivers52,500 base stations in UK

Each colour represents a base station operating at a slightly different frequency10Mobile Phones (3)Recognise the masts?Each cell has a transmitter and receiver mast Notice the typical three way structure

113G MastsPhoto Credit Brighton and Hove Green Party

12http://www.brightonandhovegreenparty.org.uk/h/n/NEWS/press_releases/ALL/254/

Hidden cell phone masts are objected too as wellhttp://www.theregister.co.uk/2010/09/24/moms_of_merrick/

Collection of Unusual Mastshttp://www.theregister.co.uk/2010/11/21/base_station_results/ Linking to base stationsMast power between 60 watts and 120 wattsHandset power less than 1 wattHandset sends signals every few minutes to establish which is the nearest mast

A central computerkeeps track of all the telephones that are switched on remembers which cell they are in13Making a mobile-to-mobile callIts complicated!Network ControlKnows in which cell every telephone isOriginating TelephoneReceiving Telephone142G or GSM phone Hello! How are you?Sound 217 pulses of encoded sound every second No sound: No signalEncoding to Radio Signal Hello! How are you? Peak Power 2 W MaximumAverage power is 0.25 W MaximumGlobal System for Mobile Communications15http://www.techmind.org/gsm/

2G or GSM phoneBase station Transmitter Frequencies(MHz)Handset Transmitter Frequencies(MHz)Peak Handset Power(Watts)Originally licensed toGSM900935 - 960890-9152O2 (Tesco)Vodafone (Asda)GSM18001805-18801710-17851Orange T Mobile (Virgin)

16http://www.techmind.org/gsm/

Anatomy of a GSM Signal

17http://www.techmind.org/gsm/ GSM phone signal analysisAfter coming by some new information, my curiosity was aroused with regard to what exactly a digital GSM mobile phone transmits. This document summarises what I found out, and actually measured.BackgroundContemporary 'digital' mobile phones in Europe operate using the GSM (Global Systems Mobile) system. There are two frequency bands allocated to GSM mobile phones, one at 900MHz, and one at 1800MHz. GSM uses a combination of frequency division multiple access (FDMA) and time division multiple access (TDMA). What this means in reality is that within each band there are a hundred or so available carrier frequencies on 200kHz spacing (the FDMA bit), and each carrier is broken up into time-slots so as to support 8 separate conversations (the TDMA bit). Correspondingly, the handset transmission is pulsed with a duty cycle of 1:8; and the average power is one eighth of the peak power. Once a call is in progress, the phones are designed to reduce the radiofrequency (RF) output power to the minimum required for reliable communication - under optimum conditions, the power can be set as low as 20mW (one hundredth of full power). Battery consumption and radiation output of the handset is further reduced by using 'discontinuous transmission' (DTX); the phone transmits very much less data during pauses in the conversation.Base station transmitHandset transmitPeak handset powerused in the UK primarily byGSM900935-960MHz

890-915MHz

2 watts

BT Cellnet and VodafoneGSM1800 (PCN)1805-1880MHz

1710-1785MHz

1 watt

Orange and One2oneThe basic handset transmission consists of carrier bursts of 0.577ms duration, repeating every 4.615ms, giving a repetition rate of 216.7Hz. The data is encoded using a phase modulation scheme known as 'Gaussian Minimum Shift Keying' (GMSK) and a symbol duration of about 4s, which doesn't affect the carrier amplitude. Owing to the coding and control protocols, every 26th pulse is omitted during a conversation, leading to a component in the output modulation at 8.33Hertz.ExperimentalI rigged up a simple circuit (crystal-set type non-tuned diode demodulator) and recorded the signal amplitude using a standard PC soundcard line-in socket.The figure below represents the amplitude of the a GSM mobile phone (Vodafone) transmission on reception of an incoming call. The interpretation of the call progress is my own, based on limited knowledge. Note how the transmitter power is reduced once the call has been set up and the conversation begins. Note also the 'gaps' during the silence in the conversation, where the transmitted signal returns to a 'holding' signal -- which looks superficially similar to the signal during ringing.The slow and smooth variation in amplitude is caused by moving the phone relative to my receiver during the measurement, and is not significant! This represents a section of the voice transmission, the timescale of the whole plot being a little over 1 second. Expanding the timescale further, the detail of the pulse structure is revealed. The pulses come at 4.62millisecond intervals (approx. 217Hz frequency), each lasting 0.57milliseconds. This gives a mark:space ratio of 1:7, allowing up to eight calls to be time-multiplexed (TDMA) onto the same carrier frequency. Every 26th pulse is omitted, causing an 8.3Hz periodicity in the signal.The plot below shows some detail of the effect of the discontinuous transmission.

2G or GSM phone

217 Pulses per second per telephone call 217 Pulses per second Each frequency channel can carry 7 calls18Magic?Not magic, just engineering!19SafetyThe safety issues surrounding mobile phones concern the interactions of the microwaves emitted by mobile phones base stationswith human tissue

20And its not just mobile phones!

WiFi Wireless NetworkingBluetooth devicesWireless keyboards and miceDECT cordless phonesBaby MonitorsWalkie Talkie

All involve electromagnetic waves in the radio and microwave part of the spectrum

21Pictures from Amazon and e-bay2. How do electromagnetic waves interact with matter?

?22Electromagnetic spectrum 11011021031041051061071081091010101110121013101410151016101710181019102010211022Radio & TVInfra RedMicrowavesGamma-RaysX-RaysUltra VioletMicrowaves0.8 GHzto 1000 GHz

Non-ionising Radiation(generally not so bad)Ionising Radiation(generally bad)Frequency (Hertz)23Notice how stupendously large is the range of frequencies, and how narrow is the range of frequencies of visible light.Remember how different a millimetre is from a kilometre? Well think how different a radio wave (1 million oscillations per second (say)) is from a light wave, (1000 million million oscillations per second ) WOW!Waves & MatterWhen an electromagnetic wave interacts with matterSome absorption Some reflectionSome transmission24SummaryElectromagnetic waves interacting with matter can beReflected, absorbed or transmittedWhat happens depends onthe frequency of the electric fieldthe natural frequencies of the atoms and molecules Microwaves emitted by mobile phone systemsAre absorbed by human tissue2511011021031041051061071081091010101110121013101410151016101710181019102010211022Radio & TVFrequency (Hertz)MicrowavesInfra RedUltra VioletX-raysGamma RaysElectrons in AtomsProtons in nucleusAtoms in solids or moleculesEntire molecules or parts of moleculesLighter particlesStronger forcesWavesWhat vibrates?26Notice how stupendously large is the range of frequencies, and how narrow is the range of frequencies of visible light.Remember how different a millimetre is from a kilometre? Well think how different a radio wave (1 million oscillations per second (say)) is from a light wave, (1000 million million oscillations per second ) WOW!Absorption demoFrequencyWell below the natural frequencyNot much absorptionWell above the natural frequencyNot much absorptionNear the natural frequencyAbsorption27Waves & MatterWhen electromagnetic waves are absorbed Atoms jiggle faster:i.e. increase their temperature.Heat

Electricity

Electromagnetic wavesAtoms

28What happens to the wave energy when it is absorbed?3. How much energy gets absorbed?

S.A.R.Specific Energy Absorption Rate29Terminology

PowerwattsIntensitywatts per square metreSpecific energy Absorption Rate (SAR)watts per kilogram301 cm from 20 W source 20 W absorbed in hand Intensity 8000 watts per square metreSAR 200 watts per kilogram

10 cm from 20 W source 2 W absorbed in hand Intensity 200 watts per square metreSAR 20 watts per kilogram

1 metre from 20 W source 0.02 W absorbed in hand Intensity 5 watts per square metreSAR 0.2 watts per kilogram

SAR: Example using lightrather than microwaves

31By Law Phones must have a MAXIMUM SAR of 2 Watts per kilogram averaged over 10 grams of tissueThe point of this slide is to show that SAR Is not a property of a device itself, but a combination of a devcie and the way it is used.Calculations assume hand has a mass of 100 g1 cm from 20 W source Roughly 20 W absorbed in hand Intensity roughly 8000 watts per square metreSAR roughly 200 watts per kilogram

10 cm from 20 W source Roughly 2 W absorbed in hand Intensity roughly 200 watts per square metreSAR roughly 20 watts per kilogram

1 metre from 20 W source Roughly 0.02 W absorbed in hand Intensity roughly 5 watts per square metreSAR roughly 0.2 watts per kilogram

Microwave HazardThe potential hazard from mobile phones and other wireless devices arises from the absorption of microwave radiationMobile phones only emit a watt or twoso little power it makes experiments difficultMicrowave ovensemit a few hundred wattsmakes experiments easy 32Microwave Ovens3a. Microwave ovens33Electromagnetic spectrum MicrowavesFrom 0.8 GHzto 1000 GHz11011021031041051061071081091010101110121013101410151016101710181019102010211022Radio & TVInfra RedMicrowavesGamma-RaysX-RaysUltra VioletMicrowavesConventional Oven200 CMicrowave Oven 2.45 GHz34Notice how stupendously large is the range of frequencies, and how narrow is the range of frequencies of visible light.Remember how different a millimetre is from a kilometre? Well think how different a radio wave (1 million oscillations per second (say)) is from a light wave, (1000 million million oscillations per second ) WOW!

Absorption of microwaves by liquid waterWell below the natural frequencyNot much absorptionWell above the natural frequencyNot much absorptionNear the natural frequencyAbsorption2.45 GHz35This is the absorption spectrum for liquid waterAbsorption (1)Too strongIf power were absorbed too strongly,Microwaves would only penetrate a short distanceSurface would be heatedInside would remain uncooked

36Absorption (2) Too weakIf power were absorbed too weakly,Microwaves would go right through No cooking

37Absorption (3)If power is absorbed just right,Microwaves penetrate about 5 cm (2 inches) Cooks the outer 5 cm of the foodGood enough for most cases

38Microwave OvensSummaryA microwave oven cooks food by heating it

The heating comes fromintense waves at 2.45 GHz (Instead of a wide spectrum of waves at infra red frequencies)

Frequency chosen because of absorption properties of water molecules at that frequency.39Microwave OvensInside a microwave oven40Microwave PowerPowerThis is a 700 watt ovenThink of 7 x 100 watt light bulbs

41Think about a 100 W light bulbMicrowave Safetyhttp://hps.org/hpspublications/articles/microwaveoven.htmlMicrowave Electric field700 watts Around 140 000 volts per metreLook what happens to a CD

42Microwave IntensityBetween 104 to 105 watts per square metre(Most intense sunlight around 103 watts per square metre)Very DangerousCould I have a stupid volunteer please?

43Think about a 100 W light bulbMicrowave Safetyhttp://hps.org/hpspublications/articles/microwaveoven.html

(that guideline is just guessed!)

Microwave OvenSAR inside oven700 watts absorbed in 1 kg of water: SAR = 700 watts per kg

Question: After 1 minute, how hot would your brain become if subject to an SAR of 700 watts per kg?

44Experiment

45Microwave OvensComparison with handsetsSAR Wattsper kilogramTemperature Rise in 1 kg of Brain FluidMicrowave7008 C (ish)Mobile Phone1Cant be measured directlyExpect 1/700 of microwave temperature riseThe effects of blood flow reduce this further0.01 C (ish)46Figures from Page 38 of Stewart report

Back to Mobile Phones 3b. Mobile Phone SAR

47

New Style

Old StyleMobile Phones (14) SAR and Safety 48http://www.speag.com/measurement/isar/flat.php

NPL can estimate the SAR for a mobile phone in a standard position near a simulated heade.g. 1.2 watts per kilogramNPL cant advise on whether that dose is safe

Mobile Phones (8) Your telephoneLook in the small print!

49EU 2 W/kg averaged over 10 gUS 1.6 W/kg averaged over 1 gTypical SAR with phone near the headSAR Averaged over 10 gramsBy law must be less than 2 watts per kilogramPowerIntensityMaximumSARWattsWatts per square metreWattsper kilogram1 2001Typical figures50Figures from Page 36 of Stewart reportBase Station SAR

51Base StationsPower

52Stewart report page 37Base Station Informationhttp://www.sitefinder.ofcom.org.uk/

53http://www.sitefinder.radio.gov.uk/

Actually for 2 G Masts the Sitefinder Data base only gives the EIRO PER Channel of the Transmitter. If more than 7 conversations are active in that Cell the output power will be higher.EIROEquivalent isotropic RadiatedOutput

Actual Pattern of Emitted Radiation60 WHow this is specified54Right underneath the base station0.3 W/m^2 maximum100 metres away 0.01 W/m^2 maximumINCIRP Guideline figure 10 W/m^2Stewart report page 37Intensity 50 metres from 10 metre tower0.01 watts per square metreSAR less than 0.001 watts per kilogram5000 times smaller than SAR from handsets

Mast near my childrens old schoolPower30 dBW 1000 W Equivalent isotropic Radiated Output60 W to 120 W in actual power

0.3Watts per square metre0.01Watts per square metreSAR 0.001Watts per kilogram55Right underneath the base station0.3 W/m^2 maximum100 metres away 0.01 W/m^2 maximumINCIRP Guideline figure 10 W/m^2Stewart report page 37Intensity 50 metres from 10 metre tower0.01 watts per square metreSAR less than 0.001 watts per kilogram5000 times smaller than SAR from handsets

Comparison of handsetsand base stationsBase station SAR is extremely lowbut you cant choose whether you want it or not!PowerIntensityMaximumSARWattsWatts per square metreWattsper kilogramHandset1200About 1Base Station60 0.01About 0.00156Figures from Page 38 of Stewart report

Wireless NetworkingWiFi802.11(b), 802.11(g), 802.11(n)Operates at 2.4 GHz

PowerIntensity(at 1 metre)SAR(at 1 metre)WattsWatts per square metreWattsper kilogram0.1 Less than 0.01About 0.000157Wikipedia on WiFiEIRP in the EU is limited to 20dbm.

A transmitter emitsMaximum Permissible Power in EUEIRP = 0.1 watt1 metre from base station intensity is 0.008 watt per square metre

Comparison of handsetsand base stations and wi-fiPowerIntensityMaximumSARWattsWatts per square metreWattsper kilogramHandset1200About 1Base Station60 0.01About 0.001Wi Fi0.1 < 0.01About 0.000158Figures from Page 38 of Stewart report

4. Are Mobile Phones Safe?

59SAR and SafetyHealth Protection AgencyBased on ICNIRP guidelineshttp://www.icnirp.de/documents/emfgdl.pdf International Commission on Non-Ionising Radiation Protectiondetermines what we believe is safe

How do they do that?They determine a borderline safe levelDivide by 10 for occupational exposureDivide by another factor 5 for general public exposure60ICNIRP:Guidelines at http://www.icnirp.de/documents/emfgdl.pdf

International Commission on Non-Ionizing Radiation ProtectionIs 2 watts per kilogram a safe value of SAR?(recommended limit for mobile phones)Is exposure to 10 watts per square metre safe?(reference level for general exposure)

What are the risks?Basic safety assumption is that the main effect of exposure to microwaves is thermal

Are there non-thermal effects?If so are they harmful?Normal thermal vibrations are much larger than vibrations induced by microwaves emitted by mobile phones.

Question of safety must be resolved by experimentExperiments are very hard

61Photon energy E =hfF = 1 GHz6.6e-34 x 1e9 = 6.6e-25 JT = 6.6e-25 J/1.38 e-23T = 6.6/1.38 x 0.01 = 0.04 KAre mobile phones safe?

Stewart Report A group of non-industry related experts

Gave rise to MTHRMobile Telecommunications and Health ResearchONGOING Research Program Funded 50:50 government & industry

62http://www.mthr.org.uk/ Stewart ReportMobile Phones and their networks are pretty safeThere may be effectsPrecautionary Approach: More research please

ChildrenDriving

63http://www.mthr.org.uk/ Mobile PhonesSuppose we discovered an effect:What might it look like?

Nora D. Volkow, Dardo Tomasi, Gene-Jack Wang, Paul Vaska, Joanna S. Fowler, Frank Telang, Dave Alexoff, Jean Logan, Christopher Wong,Effects of Cell Phone Radiofrequency Signal Exposure on Brain Glucose MetabolismJournal of the American Medical Association, February 23, 2011Vol 305, No. 864

PET ScanThis device can see you think!Glucose metabolism in this area appears to have been affected 65What could we do?What should we do?In smaller groupsPlease come up with some questions, and suggestionsWe will gather these together and then ask the expertsSuggestionSuggestionSuggestionQuestionQuestionYou decide!66

See you next week to discuss Nuclear PowerGoodnight

67Mobile PhonesUnused Slides

68Perception of riskRisk is expressed mathematically, but our judgement of risk is not mathematicalMore willing to take riskLess willing to take riskExampleBenefitsDirectIndirectBase Stations/Mobile PhonesTechnologyFamiliarUnfamiliarCars/Mobile PhonesExposureVoluntaryInvoluntaryBase Stations/Mobile PhonesExposureFairUnfairPoverty/WealthExposurePersonal ControlNo Personal ControlDriver/PedestrianConsequenceNot DreadedDreadedCancer/ Broken bone69From Talk by Benjamin LoaderDirect vs. Indirect benefits: People are much happier to accept some risk if there is a direct benefit to them. Familiar vs. unfamiliar: The more familiar people are with the technology, the lower the perceived risk. Voluntary vs. involuntary exposure: Fairness vs. unfairness: Building council houses on land near to power lines may appear to be unfair, since one economic group is bearing all the potential risks. Personal control vs. lack of control: Perceived risk is increased if people feel they have no say in the location of installations, and that these things are being forced upon them.Not dreaded vs. dreaded: Some diseases are dreaded, such as cancer, and even a small possibility from EMF, especially in children, greatly increases the perceived risk.

Electromagnetic waves

ElectricityHeat

How it all fits togetherAtomsAnd a pictorial summary for those who appreciate things that way.A Cautionary TaleDont try this at home!August 14, 2002 I don't want to sound like I know everything in the world or even like I know quite a lot. But you had a question regarding If a microwave oven door were to open while it was still on, what would happen? Could it hurt you?- JP Well ..Having the thought process that I have, kinda how should I put it? ...Stupid? or inventive or even in-between. Well, my microwave door did happen to come off. Magic Chef 900-watt microwave. Well, I did my best to try to fix it but the hinge on one side did not attach properly, therefore having a gap between the door and the appliance. Being me (stupid) I wondered if it would burn fast or would it gradually warm up. I slid my finger between...You probably dying to hear what happened... But it didn't gradually warm up at all. It was instant heat! It didn't scar me or anything like that, but sure scared the H*** out of me to find out it got so hot so quick. I didn't get any blisters either. But it just burned like touching something hot on the tip of my finger being that is the only thing I put in. Well you know the old adage, "You learn from your mistakes", stands true. lol -

71http://rabi.phys.virginia.edu/HTW/microwave_ovens.htmlDo I have to say Dont try this at home?Mobile PhonesSuppose we discovered an effect:What might it look like?

R Luria, I Eliyahu, R Hareuveny, M Margaliot, N, MeiranCognitive Effects of Radiation Emitted by Cellular Phones: The influence of exposure side and timeBiolectromagnetics 30: 198-204 (2009)Possibility#172No MatchClick with Left Hand73MatchClick with Right Hand74Task Completed with PhoneOn LEFTOn RIGHTOFF75RESULTS

1 hour1 hour76RESULTSWith Uncertainty

Only these two points have statistical significance77What could we do?Ban mobile phones ?The Precautionary principleCould there be some harm caused?How many lives are saved by mobile phones?Reduce mobile phone power ?Increase the number of mobile phone mastsReduce mast power ?Increase the mobile phone handset powerIncrease the number of mastsBan mobile phone use while driving ?Done: has it been effective?Nothing ?78About Electro-Magnetic Fields (EMFs):Many sources of EMF already exist. EMF from the equipment will be low compared to the safety guideline levels, and EMF at these levels are safe and do not cause cancer. EMF are not the same as ionising radiation

Mast

Roughly hexagonal cells

6 degrees

50 m to 200 m

6 degrees

50 m to 200 m

Actual Pattern of Emitted Radiation

1000 W

EiRO