Biological Aspects of Biological Aspects of Mobile Communication Mobile Communication

FieldsFields

Presentation by Parag Tengshe under Presentation by Parag Tengshe under the guidance of Dr. Yeong Kimthe guidance of Dr. Yeong Kim

IntroductionIntroduction Wireless communication service is the Wireless communication service is the

two way radio communication using RFtwo way radio communication using RF Exposure to RF and microwave energy Exposure to RF and microwave energy

emitted by telecommunication devicesemitted by telecommunication devices Continuous but very low exposure from Continuous but very low exposure from

base station to the whole bodybase station to the whole body Intermittent and more intense Intermittent and more intense

exposure from the handset to the headexposure from the handset to the head Need to understand the biological Need to understand the biological

effects of RF electromagnetic field effects of RF electromagnetic field

Electromagnetic Radiation (EMR)Electromagnetic Radiation (EMR)

Consists of electric and magnetic fieldConsists of electric and magnetic field Interaction of these fields with matter Interaction of these fields with matter

determining the effects of EMRdetermining the effects of EMR Mobile phone system operating at about Mobile phone system operating at about

900 and 1800 MHz for GSM and 800 MHz 900 and 1800 MHz for GSM and 800 MHz for CDMA can be referred as both for CDMA can be referred as both microwave radiation and radio frequency microwave radiation and radio frequency radiation. radiation.

Base StationBase Station

Different cells using Different cells using different frequencies to different frequencies to prevent interferenceprevent interference

Large number of Large number of antennas does not antennas does not mean greater RF mean greater RF exposure as maximum exposure as maximum power will be power will be transmitted when all transmitted when all users operating at the users operating at the same timesame time

The Mobile PhoneThe Mobile Phone

CDMA phone average transmission CDMA phone average transmission power 200mW while GSM digital power 200mW while GSM digital phone average transmission power is phone average transmission power is 250mW250mW

Lower exposure of CDMA compared Lower exposure of CDMA compared to GSMto GSM

Interaction of RFR with MatterInteraction of RFR with Matter RF radiation absorption causing molecules to RF radiation absorption causing molecules to

vibrate, resulting in heating vibrate, resulting in heating Thermal effect –Thermal effect –basis for determining health basis for determining health

hazard from RF exposurehazard from RF exposure Distance within a wavelength from a RF Distance within a wavelength from a RF

transmitter is known as near fieldtransmitter is known as near field GSM(900 MHz) near field region is 30cmGSM(900 MHz) near field region is 30cm User’s head disturbs the field and alters the User’s head disturbs the field and alters the

manner in which RFR interacts with tissuesmanner in which RFR interacts with tissues This interaction causes complicates the This interaction causes complicates the

absorption of RF energy and makes calculations absorption of RF energy and makes calculations difficultdifficult

Absorption Of RFR From Mobile PhoneAbsorption Of RFR From Mobile Phone

RF absorption in the RF absorption in the head from a mobile head from a mobile phone held next to the phone held next to the left earleft ear

Green region Green region represents peak represents peak absorption and absorption and corresponds to peak corresponds to peak SAR of 2-3W/kgSAR of 2-3W/kg

SAR of 4W/kg SAR of 4W/kg associating with 1 associating with 1 degree temperature degree temperature riserise

Exposure to RFR By Base StationExposure to RFR By Base Station

RFR power emitted RFR power emitted from a base station from a base station varies from one site varies from one site to anotherto another

Graph about variation Graph about variation of power density with of power density with distance from base distance from base stationstation

Peak value is Peak value is 0.1µW/cm. 0.1µW/cm. Maximum allowed Maximum allowed exposure is exposure is 500µW/cm500µW/cm

Biological Effects of RFRBiological Effects of RFR

Cancer induction and promotionCancer induction and promotion Nervous system effects--blood-brain Nervous system effects--blood-brain

barrier (BBB) permeability changesbarrier (BBB) permeability changes Nervous system effects-the Nervous system effects-the

microwave auditory effectmicrowave auditory effect Cataractogenic and other effects on Cataractogenic and other effects on

ocular systemocular system Epidemiology and human studiesEpidemiology and human studies

Cancer Induction And PromotionCancer Induction And Promotion

Exposure to 915 and 2450 MHz promoting Exposure to 915 and 2450 MHz promoting tumor growth in animals only if tumor is tumor growth in animals only if tumor is first initiated by other meansfirst initiated by other means

Modest changes in proliferation of human Modest changes in proliferation of human glioma cells following 2-hr of exposure to glioma cells following 2-hr of exposure to 2450 MHz at 5 W/kg2450 MHz at 5 W/kg

Acute(2-hr) whole body exposure to 2450 Acute(2-hr) whole body exposure to 2450 MHz microwaves, causing DNA damage in MHz microwaves, causing DNA damage in brain cells of rats. brain cells of rats.

An increase in single and double strand An increase in single and double strand DNA breaks after exposure to either DNA breaks after exposure to either pulsed or CW radiation for 4 hours and pulsed or CW radiation for 4 hours and SAR was 1-2 W/kgSAR was 1-2 W/kg

Continued…Continued…

Relatively high SARs used for the Relatively high SARs used for the experiments (6-12 W/kg) that were experiments (6-12 W/kg) that were known to cause appreciable known to cause appreciable temperature increasetemperature increase

In another experiment, pulsed In another experiment, pulsed microwave exposure for 25 months microwave exposure for 25 months caused significant malignancies in caused significant malignancies in ratsrats

Continuous exposure did not reveal Continuous exposure did not reveal any significant effects on general any significant effects on general health in ratshealth in rats

Continued…Continued…

Frequencies and modulations specific Frequencies and modulations specific to mobile phone(915 MHz RF fields) to mobile phone(915 MHz RF fields) did not show any significant did not show any significant difference in tumor growth between difference in tumor growth between microwave and sham exposed ratsmicrowave and sham exposed rats

Prolonged exposure to mobile phone Prolonged exposure to mobile phone microwave fields did not promote microwave fields did not promote growth of either the faster or slower growth of either the faster or slower growing gliomas beyond their normal growing gliomas beyond their normal course.course.

BBB Permeability ChangesBBB Permeability Changes

Several experiments using high and Several experiments using high and low levels of microwave exposures low levels of microwave exposures showing microwave-induced increase showing microwave-induced increase in BBB permeabilityin BBB permeability

Other studies not finding any Other studies not finding any microwave-induced disruption of BBBmicrowave-induced disruption of BBB

Effect of microwave radiation on BBB Effect of microwave radiation on BBB permeability remains controversialpermeability remains controversial

Continued…Continued… Barrier permeation appears to have Barrier permeation appears to have

been observed at all levels of RF been observed at all levels of RF including those at extremely low including those at extremely low level (0.016 W/kg)level (0.016 W/kg)

Possibility of increase in temperature Possibility of increase in temperature of brain to 42˚C or higher at high of brain to 42˚C or higher at high SAR (165 W/kg)SAR (165 W/kg)

Above conclusion is supported by Above conclusion is supported by heating of the rat’s brain by heating of the rat’s brain by conventional means causes conventional means causes disruption of the BBBdisruption of the BBB

The Microwave Auditory EffectThe Microwave Auditory Effect

Pertains to the auditory sensation of Pertains to the auditory sensation of radar-like pulses by humans and radar-like pulses by humans and laboratory animalslaboratory animals

The effect occurring at power density The effect occurring at power density threshold of 400mJ/m for a single threshold of 400mJ/m for a single microsecond wide pulse of 2450 MHz microsecond wide pulse of 2450 MHz

Microwave exposure across a wide Microwave exposure across a wide range of frequencies (1245-3000 range of frequencies (1245-3000 MHz) causing the effect MHz) causing the effect

Continued...Continued... Little data regarding the effect on the Little data regarding the effect on the

middle and inner ears hearing middle and inner ears hearing apparatus or central nervous system apparatus or central nervous system from exposure to microwave pulsesfrom exposure to microwave pulses

No proper investigation of any health No proper investigation of any health effect regarding exposure to pulsed effect regarding exposure to pulsed microwave radiationmicrowave radiation

Current research using RF radiation Current research using RF radiation from mobile phone operations may from mobile phone operations may provide some insightprovide some insight

Cataractogenic And Other Effects Cataractogenic And Other Effects On Ocular SystemOn Ocular System

Concern regarding formation of Concern regarding formation of cataracts due to microwave cataracts due to microwave

Production of lens opacities in the Production of lens opacities in the eyes of laboratory animals following eyes of laboratory animals following acute microwave exposureacute microwave exposure

Subject of debate regarding the Subject of debate regarding the conditions under which higher levels conditions under which higher levels of CW radiation causes lens of CW radiation causes lens opacification opacification

Continued…Continued… One of the most intensively investigated One of the most intensively investigated

frequency is 2450 MHz, used for WLANsfrequency is 2450 MHz, used for WLANs Lens opacities found in rabbits when exposed to Lens opacities found in rabbits when exposed to

near field of 2450 Mhz CW microwaves with near field of 2450 Mhz CW microwaves with SAR of 138 W/kgSAR of 138 W/kg

No cataract found in rhesus monkeys when No cataract found in rhesus monkeys when exposed to different SAR level. exposed to different SAR level.

Isolated rat lenses produced histopathological Isolated rat lenses produced histopathological damages at the lens equator with high power damages at the lens equator with high power 918 MHz pulses of 10-microsecond width 918 MHz pulses of 10-microsecond width

4.7 times greater damage than CW radiation4.7 times greater damage than CW radiation

Continued…Continued…

Ultrastructural degeneration of retinal Ultrastructural degeneration of retinal neurons observed in rabbits at power neurons observed in rabbits at power level of 55 mW/cmlevel of 55 mW/cm

Corneal lesions found in juvenile Corneal lesions found in juvenile monkeys kept under anesthesia after 4-monkeys kept under anesthesia after 4-hr/day exposure to 2450 MHz hr/day exposure to 2450 MHz microwaves (pulsed and CW)microwaves (pulsed and CW)

No corneal abnormalities reported when No corneal abnormalities reported when monkeys were not anesthetizedmonkeys were not anesthetized

Epidemiology And Human StudiesEpidemiology And Human Studies Epidemiology offers a valuable Epidemiology offers a valuable

investigation tool to access the potential investigation tool to access the potential association between cancer and association between cancer and exposure to electromagnetic energyexposure to electromagnetic energy

Case reports of cataracts in humans Case reports of cataracts in humans following accidental exposure to following accidental exposure to microwave radiationmicrowave radiation

No association found between military No association found between military microwave operation and cataractmicrowave operation and cataract

No effect of microwave exposure on No effect of microwave exposure on growth and development of childrengrowth and development of children

Continued…Continued…

No evidence of higher mortality in the No evidence of higher mortality in the Moscow Embassy personnel who were Moscow Embassy personnel who were exposed to microwave radiationexposed to microwave radiation

High exposure cohorts and low exposure High exposure cohorts and low exposure cohorts from US Navy personnel did not cohorts from US Navy personnel did not reveal any difference in the mortality ratereveal any difference in the mortality rate

Difficulty in above studies is the Difficulty in above studies is the uncertainty in accessing actual exposure uncertainty in accessing actual exposure to large numbers of peopleto large numbers of people

Continued…(Brain Tumor Risk)Continued…(Brain Tumor Risk)

Relative risk for brain tumor elevated to Relative risk for brain tumor elevated to (RR=1.6) among all males exposed to RF (RR=1.6) among all males exposed to RF and microwave radiationand microwave radiation

Excess risk of (RR=2.3) for RFR Excess risk of (RR=2.3) for RFR associated with jobs involving design, associated with jobs involving design, installation, maintenance or manufacture installation, maintenance or manufacture of electrical or electronic equipmentof electrical or electronic equipment

No increase in brain tumor risk who have No increase in brain tumor risk who have never worked in electrical or electronic never worked in electrical or electronic jobsjobs

Continued…Continued… Increased mortality reported for certain cancers Increased mortality reported for certain cancers

like brain tumor(1.4), leukemia(1.8) and cancer like brain tumor(1.4), leukemia(1.8) and cancer in some lymphatic tissues(1.6) when exposed to in some lymphatic tissues(1.6) when exposed to stronger RF fieldstronger RF field

Relative risks of children for some cancers were Relative risks of children for some cancers were not elevated if they lived within 3.5 km of a not elevated if they lived within 3.5 km of a microwave tower in San Franciscomicrowave tower in San Francisco

The case study regarding the relation between The case study regarding the relation between RF exposure and brain tumor risk of males in RF exposure and brain tumor risk of males in US Air Force between 1970-89 is weakened by US Air Force between 1970-89 is weakened by small numbers and lack of exposure small numbers and lack of exposure assessment i.e. dosimetry dataassessment i.e. dosimetry data

Further Epidemiological StudiesFurther Epidemiological Studies

Difficult to demonstrate conclusively Difficult to demonstrate conclusively that RFR exposure is not a health that RFR exposure is not a health hazardhazard

What is happening in the human What is happening in the human brain remains an absolute enigmabrain remains an absolute enigma

No direct relation between a No direct relation between a biological effect in cells in the lab biological effect in cells in the lab and a health effect and a health effect

ConclusionConclusion

Agreement in studies about induction of Agreement in studies about induction of higher SARs by microwave exposurehigher SARs by microwave exposure

Rising of brain temperature to 42ºC or Rising of brain temperature to 42ºC or higher at sufficiently high SARhigher at sufficiently high SAR

Increase of BBB permeability Increase of BBB permeability Only small number of case reports of Only small number of case reports of

cataracts in humans following cataracts in humans following accidental exposureaccidental exposure

Microwave auditory effect is a high Microwave auditory effect is a high power phenomenon occurring at low power phenomenon occurring at low average poweraverage power

Continued…Continued… Lack of investigation corresponding Lack of investigation corresponding

exposure to pulsed microwave radiation exposure to pulsed microwave radiation over prolonged timeover prolonged time

Controversy on the effects of RFR on BBB Controversy on the effects of RFR on BBB permeability and lens ultrastructure at permeability and lens ultrastructure at low SAR levelslow SAR levels

Many reports suffering from a lack of Many reports suffering from a lack of realistic measures of RFR results in realistic measures of RFR results in reducing usefulness for risk analysisreducing usefulness for risk analysis

Urgent need for epidemiological studies Urgent need for epidemiological studies of RF effects on mobile phone usersof RF effects on mobile phone users

Continued…Continued… Well established fact that RFR can produce Well established fact that RFR can produce

deleterious biological effects at sufficiently high deleterious biological effects at sufficiently high power levelspower levels

Available data does not suggest any immediate Available data does not suggest any immediate cause for concern of an impending threat to the cause for concern of an impending threat to the health of humanshealth of humans

Need for answering specific questions before Need for answering specific questions before dependable scientific conclusionsdependable scientific conclusions

Investigation to answer some of the questions Investigation to answer some of the questions has already begun has already begun

Quantitative information required for Quantitative information required for extrapolation from animal experimentation to extrapolation from animal experimentation to human responsehuman response

How can the Potential Risks Be How can the Potential Risks Be Reduced?Reduced?

Limiting the use of mobile phones Limiting the use of mobile phones both in terms of number of calls and both in terms of number of calls and call durationcall duration

Avoiding the use of mobile phones in Avoiding the use of mobile phones in enclosed spacesenclosed spaces

Holding phone away from your earHolding phone away from your ear Using ‘hands free’ mobile phone kits Using ‘hands free’ mobile phone kits

and RFR shielding devicesand RFR shielding devices Purchasing mobile phones with lower Purchasing mobile phones with lower

power outputspower outputs

ReferencesReferences

Biological aspects of mobile Biological aspects of mobile communication fields – James C. Lincommunication fields – James C. Lin

www.arpansa.gov.au – The Mobile www.arpansa.gov.au – The Mobile Phone System and Health Effects Phone System and Health Effects

www.globalchange.comwww.globalchange.com

Thank YouThank You