Cell phone and mobile tower radiation hazards

Radiation Hazards from Cell Phones/Cell TowersProf. Girish KumarElectrical Engineering DepartmentIIT Bombay, Powai, Mumbai(022) 2576 7436gkumar@ee.iitb.ac.inOUTLINE OF PRESENTATIONRF sourcesRadiation Pattern of Cell tower AntennaEMF exposure Safety normsRadiation measurements near cell towers Review Biological effects Case StudiesElectromagnetic RadiationsRadiation emitted from Cell Phones, Cell phone towers, Wi-Fi, TV and FM towers, microwave ovens, etc. are called Electromagnetic radiations (EMR). EMR causes significant health hazards (biological effects) on human, animals, birds, plants and environment.RF SourcesFM TOWERPT=10KW503 TOWERS (88-108MHz)TV TOWERPT=40KW1044 TOWERS (180-220MHz)AM TOWERPT=100 KW 197 TOWERRF SOURCES (540-1600KHz)IN INDIAWi-FiPT=10-100mWWi-Fi HOT SPOTS(2.4 - 2.5 GHz)CELL TOWER4.3 LAKHS (800,900,1800 PT=20 WTOWERS MHz)GSM-1800 - 1 W MOBILE PHONES600+ million GSM-900 -2 W Microwave radiation effects are classified as: •Thermal •Non-thermalThe current exposure safety standards are mainly based on the thermal effects, which are inadequate.Non-thermal effects are several times more harmful than thermal effects.Microwave Heating Concept4.2 KW (4200 W) of microwave power raisestemperature of 1 Litre of water by 10C in 1 second.In energy absorption term, 4.2 KW-sec microwaveenergy will increase the temperature of 1 Litre by 10C.For example, in a microwave oven, temperature of onecup of water increases from 300C to 1000C in approx.70 seconds with 500W of microwave power. With 1Wpower (same as output power of cell phones), temp.will increase by 10C in 500 seconds.Temp. of ear lobes increases by approx. 10C when cellphone is used for approx. 20 minutes.Cell Phone and Tower Statistics in IndiaWorldwide:India:4.6 billion mobile subscriptionsPopulation - 1.15 billionMobile subscriber base - 65crores. Mobile Towers - Nearly 4.5 Growing at 1.5 crore/month, highest in lakhs to meet the the world (TRAI, June 2010). communication demand. SAR and Cell phone use time limit A Cell phone transmits 1 to 2 Watts of power SAS RA (R SpS ep cifif c abs ab orsptp ion on rate) - RaR te a t w hiw chi h radiadi tion iison i s absorbs bed by humby ahum n body, n body mem asurs ed in unid itn uni s s of wa w tts s pe r kg kg (W/kg)kg of tisi ss ues . In Un SU AS , A SAS RA R lil mi im ti for celll l phones is s i s 1.6W/1.6W Kg whiw chi h ish i s actualll y flor 6 m6 im nun tu es.s It has as sa s fety my am rgig n i of 3 to 4, so ao 4, s person sshoulon sd houl not use us celll phonel f or mor m e than 18 to 24 mio 24 m nun tu es s pep r d ayd.ayThiT s infornf mor am ta ion is not c omcmom onlmy y known know to peoplo pee ie n Indin Ia.aSAR Output ManufacturerModel(W/Kg)MotorolaV1951.6MotorolaRival1.59Sony EricssonSatio (Idou)1.56BlackBerryCurve 83301.54NokiaE71x & X61.53LGRumor1.51BlackBerryBold1.51SamsungS3650 Corby 0.75Check SAR Values: SamsungSGH-G8000.23Samsung Blue Earth0.196Search on InternetSAR is expressed in Watts per KilogramSAR mobile phone Current UK Standard = 1.0W/KgCurrent US Standard = 1.6W/KgSan Francisco Govt. has made it mandatory for the industry to display SAR value for each phone. (USA Today 14 July, 2010)Antennas on Cell tower transmit in the frequency range of:• 869 - 890 MHz (CDMA)• 935 - 960 MHz (GSM900) • 1805 – 1880 MHz (GSM1800)• 2110 – 2170 MHz (3G)*