Cell Phone and Cell Tower Radiation Norms


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Better Radiation Norms for Cell Phones/Cell Towers - Prof. Girish Kumar , IIT Bombay

Presentation at Bombay Telephone User’s Association ( BTUA ), Mumbai on Jan 2010 - Consumer Awareness and Radiation Health Hazards from cell phones and mobile towers - Myth or Reality

The Indian government has adopted the ICNIRP guidlenes for cell tower radiation exposure which are the worst in the world. Several health effects have been reported much below these ICNIRP guidelines.

The ICNIRP state that these guidelines are only for short term exposure and considers only thermal effects and does not take account non thermal effects which are more harmful and occurs much below thermal effects. According to our calculations the ICNIRP guidleines implies that a human body can be safely kept in a microwave oven for 1166 secs = 19 minutes per day!! (see presentation for calculations)

In USA, max. SAR limit for cell phones is 1.6W/Kg which is for 6 minutes. It has a safety margin of 3 to 4, so a person should not use cell phone for more than 18 to 24 minutes per day. This information is not commonly given to users.

In Usha Kiran Building, Worli four cancer cases were reported until now from cell phone towers on the opposite building at about 50 meter. However, in the event one of the residents mentioned that the number of cancer cases had risen to six now and these cases were reported on the 5th, 6th (2 cases), 7th, 8th and 10th floor, all these houses are in direct line of sight from the tower installed on the opposite building on the 7th Floor.

Besides human health, electromagnetic radiation has also effected the environment, birds, animals, plants and fruit production.

Other countries based on the cases reported and their studies have adopted much lower radiation norms to protect their citizens.

All this calls for immediate need to adopt strict and lower radiation norms.

In the end, some suggestions have been given which can be adopted as possible solutions to minimize the risk of EMF radiation from cell towers.

Cell Phone and Cell Tower Radiation Norms

  1. 1. Better Radiation Norms for Cell Phones/Cell Towers Prof. Girish Kumar Electrical Engineering Department IIT Bombay, Powai, Mumbai (022) 2576 7436 gkumar@ee.iitb.ac.in
  2. 2. Outline of PresentationCell Phones – Bane or BoonMicrowave Heating PrincipleCell Phone – SARRadiation Pattern of Cell tower antennaInternational Radiation NormsImplementation of safe radiation normsConclusion
  3. 3. Electromagnetic RadiationsRadiation emitted from Cell Phones, Cellphone towers, Wi-Fi, TV and FM towers,microwave ovens, etc. are calledElectromagnetic radiations (EMR).EMR causes significant healthhazards on human, animals, birds,plants and environment.
  4. 4. India: Population - 1.15 billionMobile Towers - 4.5 lakhsto meet communicationdemand.Mobile subscriber base -70crores. Growing at 2crores/month.
  5. 5. Cell phones have several advantages.Cell phones and cell towers have severaldisadvantages including microwaveradiation, which has several harmfuleffects.
  6. 6. Microwave radiation effects are classified as:•Thermal•Non-thermalThe current exposure safety standards aremainly based on the thermal effects, whichare inadequate.Non-thermal effects are several times moreharmful than thermal effects.
  7. 7. 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 ofone cup of water increases from 300C to 1000C inapprox. 70 seconds with 500W of microwave power.With 1W power (same as output power of cellphones), temp. will increase by 10C in 500 seconds.
  8. 8. Sun Heating vs Microwave Heating Outside to inside Inside to outsideheating heatingSkin heating Internal heatingSweating happens Heat trapped
  9. 9. Cell Phone - Ear Warming?Have you ever noticed the warmsensation in ear after using mobilephone for a long time?Temp. of ear lobes increases by 10C whencell phone is used for approx. 20 minutes.Warm sensation > pain > tinnitus > irreversible hearing loss All these effects lead to Ear Tumor Tinnitus or “Ringxiety”- sensation of cell phone ring
  10. 10. SAR and Cell phone use time limit A Cell phone transmits 1 to 2 Watts of powerSAR (Specific absorption rate) - Rate at which radiation is absorbedby human body, measured in watts per kg (W/kg).In USA, max. SAR limit for cell phones is 1.6W/Kg which is for6 minutes. It has a safety margin of 3 to 4, so a person should not usecell phone for more than 18 to 24 minutes per day.This information is not given to people in India.
  11. 11. Warning from Blackberry
  12. 12. Results of Re-evaluation of Interphone StudyINTERPHONE – WHO -10 years, 13 countries, largest (5,117 braintumor cases), $25 million dollars to evaluate risk on brain tumors.Conclusion - no overall risk, but sugges ons of glioma -heavy users & ipsilateral exposuresRe-evaluation - Risk underestimated by at least 25% For every 100 hours of use -26% risk of meningioma Ini al 24% risk of glioma to 55% - regular users are taken as taken as people who use it for 2hrs/month. Doubled - quadrupled brain tumor risk - heavy users (1/2 hour/day). Children, young adults– excluded. New study - Mobi-kids
  13. 13. Cell Tower Transmit FrequenciesAntennas on Cell tower transmit in the frequencyrange of:• 869 - 890 MHz (CDMA)• 935 - 960 MHz (GSM900)• 1805 – 1880 MHz (GSM1800)• 2110 – 2170 MHz (3G)
  14. 14. Cell Towers Installed in Mumbai
  15. 15. Radiation Pattern of Antenna
  16. 16. Radiation Pattern of a Cell Tower AntennaPropagation of "main beam“ from antenna mounted on a tower or roof top People living within 50 to 300 meter radius are in the high radiation zone (dark blue) and are more prone to ill-effects of electromagnetic radiation.
  17. 17. Usha Kiran Building, Mumbai – several cancer Usha Kiran BuildingFour cancer cases in 3 consecutive floors (6th, 7th and 8th) directlyfacing and at similar height as the mobile phone towers of fourtelecom companies placed on the roof of opposite building.
  18. 18. Power Density CalculationsPower density Pd at a distance R is given by  Pt × Gt  Pd =  2   4πR  Watt/m2Pt = Transmitter power in WattsGt = Gain of transmitting antennaR = Distance from the antenna in meters
  19. 19. Power Density at distance from cell tower For Pt = 20 W, Gt = 17 dB = 50 Distance R Pd Pd (m) (W/m2) (µW/m2) 1 79.6 79,600,000 3 8.84 8,840,000 5 3.18 3,180,000 10 0.796 796,000 50 0.0318 31,800 100 0.008 7,960 500 0.000318 318 Above values are for a single carrier and a single operator. For multiple carriers and multiple operators on the same roof top or tower, above values increase manifold.
  20. 20. Power Density for multiple carriers and operators For Pt = 20 W, Gt = 17 dB = 50 No. of carriers = 5, No. of operators = 3 Distance R Pd Pd (m) (W/m2) (µW/m2) 1 1194.0 1194,000,000 3 126.0 126,000,000 5 47.7 47,700,000 10 11.94 11,940,000 50 0.477 477,000 100 0.1194 119,400 500 0.00477 4,770 For 5 carriers and 3 operators on the same roof top or tower, the radiation level is extremely high.
  21. 21. International Exposure Standards and Guidelines International Exposure limits for RF fields (1800MHz) 9.2 W/m² ICNIRP and EU recommandation 1998 – Adopted in India 3 W/m² Exposure limit in Canada (Safety Code 6, 1997) 2 W/m² Exposure limit in Australia 1.2 W/m² Belgium (ex Wallonia) 0.5 W/m² Exposure Limit in Auckland, New Zealand 0.24 W/m² Exposure limit in CSSR, Belgium, Luxembourg 0.1 W/m² Exposure limit in Poland, China, Italy , Paris 0.095 W/m² Exposure limit in Switzerl, Italy in areas with duration > 4hours 0.09 W/m² ECOLOG 1998 (Germany) Precaution recommendation only 0.025 W/m² Exposure limit in Italy in sensitive areas 0.02 W/m² Exposure limit in Russia (since 1970), Bulgaria, Hungary 0.001 W/m² "Precautionary limit" in Austria, Salzburg City only0.0009 W/m² BUND 1997 (Germany) Precaution recommendation only0.00001W/m² New South Wales, Australia
  22. 22. Table from Haumann Thomas, et al, Germany
  23. 23. GSM cell tower power density levels – percentiles (Haumann T. et al, Germany)
  24. 24. Other Standards and Guidelines•BioInitiative Report 2007 - 1000 μW/m2 for outdoor,cumulative RF exposure•Building Biology Institute, Germany, provided followingguidelines for exposure: a. <0.1 μW/m2 (0.00001 μW/cm2) - no concern b. 0.1 - 10 μW/m2 (0.00001 to 0.001 μW/cm2) - slight concern c. 10 - 1000 μW/m2 (0.001 to 0.1 μW/cm2) - severe concern d. > 1000 μW/m2 ( > 0.1 μW/cm2) - extreme concern•We recommend safe power limit up to 50µW/m2 with upper limit as 100 µW/m2.
  25. 25. ICNIRP guidelinesIndia adopts ICNIRP guideline for Power density (Pd) = Frequency /200, frequency is in MHzFor GSM900 (935-960 MHz), Pd = 4.7W/m2 and GSM1800 (1810-1880 MHz), Pd = 9.2W/m2.ICNIRP has considered only thermal effects of radiationand has given following disclosure:ICNIRP is only intended to protect the public againstshort term gross heating effects and NOT againstbiological effects such as cancer and genetic damagefrom long term low level microwave exposure frommobile phones, masts and many other wireless devices.http://ww.icnirp.de/documents/emfgdl.pdf
  26. 26. Power Absorbed by Human BodyMicrowave power absorbed by human body if exposed to so calledsafe radiation level adopted in India, which is f/200, where f is in MHz? ICNIRP Guideline – Power received (Pr) by 56" X At 940 MHz, Power human body will be density (Pd) is [Pr = Pd x Area] = 6.75 34" 4.7W/m² Watts in one sec. Area = 1.43 m² Microwave oven: 700 to 1000 W. In one day, microwave energy With say 60% efficiency, microwave absorbed will be [6.75 Watts x power output is say 500 W. 60x60x24 sec] = 583.2 KW-sec. This implies that human body can be safely kept in a microwave oven for 1166 secs = 19 minutes per day
  27. 27. Power absorbed by human body near cell towerCan one stand in front of a cell tower at 1 mdistance for 4 hours continuously? For Pt = 20 W, Gt = 17 dB = 50At 1m, Power density = 79.6 W/m²Power absorbed in one sec = Pd x .7 (for ½ area) = 55.7 WEnergy absorbed in 1 hour = 55.7 x 3600 = 200.5 kW-secFor a human body of weight 60 Kg, liquid content at70% is 42 Litres. So, temp. rise will be 20F.In 4 hours, temp. rise will be 8 0F. Normal body tempwill increase from 98.4 to 106.4 0F. Can one survive?
  28. 28. Power Received by an AntennaPower Received Pr by an antenna at a distance R: 2 Pt × Gt × Area  λ  Pr = 2 = Pt × Gt × Gr ×   4πR  4πR  For a transmitter power, Pt = 20 W Transmitting antenna gain, Gt = 17.0 dB = 50 Receiving monopole antenna gain, Gr = 2 dB =1.6 Received power at R = 50 m is: At 940 MHz, Pr = 0.413 mW = -3.8 dBm At 1840 MHz, Pr = 0.108 mW = -9.7 dBmPower density is 31,800 µW/m2
  29. 29. Radiation level measurements near Cell Tower sitesBroadband monopole antenna of gain = 2 dB wasused to measure radiated power from cell towers(CDMA, GSM900 and GSM1800) 50m 100mMeasured Power -20 to -30 dBm -30 to -50 dBm (in dBm)for each frequency bands
  30. 30. Radiation levels near Cell Tower sites• Measured power is less than theoretically calculatedpower as the concrete wall provides some attenuationand also these buildings were not directly in thedirection of maximum radiation of transmittingantenna.• A mobile phone requires -80 to -100 dBm power forits proper operation. Thus power level at 50m is 50 to60 dB (100,000 to 1,000,000 times) more than requiredby mobile phone.
  31. 31. Radiation Measurement at various locations Cumulative Readings including CDMA, GSM 900, and GSM 1800 Reading in Readings in Readings in Location dBm W/m2 microW/m2Delhi-Gurgaon Highway - near Toll (3 towers) 0 0.121 121000Vashi Bridge - after Railway Station -4 0.0481 48100Resident 1, 4th Fl: Sergean House Lady w/cancer -6 0.0304 30400Resident 2, Opposite roof, Rane Society, Powai -10 0.012 12000 Near Hub mall, Goregaon -10 0.012 12000Gandhi Nagar Over railway bridge-near building -12 0.00763 7630Ustav Chowk, Kharghar -12 0.00763 7630Vikroli - before Godrej -14 0.00481 4810Govandi- Residential towers - near Indian Oil -14 0.00481 4810Belapur Flyover, near RBI- CIDCO -16 0.00304 3040Vashi Highway – near Turbhe -18 0.00192 1920Nerul Bridge -20 0.00121 1210Vivero pre School (opposite powai lake) -22 0.000763 763Powai police station -22 0.000763 763Rajeev Gandhi nagar -26 0.000304 304On road near Evita (Hiranandani Building) -28 0.000192 192D-Mart,Hiranandani, Powai -34 0.0000481 48.1IIT Bombay School of Management - Entrance -46 0.00000304 3.04
  32. 32. Radiation Effects on the bodyMultiple Resonances - localized heating - results inboils, drying up the fluids around eyes, brain, joints,heart, abdomen, etc.
  33. 33. Measurement inside an Apartment -6 -4 -6 -4 -6 -6 -10 -10 -8 -6 -6 -24 -12 -14 -18 -12 -30 EntranceSERGEANT HOUSE Residence (4th Floor) - Lady has beendiagnosed with cancer - Cell phone towers few 10 metersaway close to window in main beam. Measured Power levelsusing Radiation Monitor are in dBm, which are very high.
  34. 34. Health concerns with current Safety Guidelines
  35. 35. Limit to radiation absorption by human bodyPeople are absorbing the harmful EM radiationscontinuously without even being aware of it, butthere is a limit of Radiation absorption.If a ball pen is slightly pressed on the finger once, nothinghappens; but pressed 1000’s of times, blood will come out. Once Multiple Times
  36. 36. Effect on EnvironmentHave you ever seen any bird near cell towers?May be not because birds have more volume andless weight, so heating effect is very fast. 4 cell towers near Gurgaon-Delhi Toll Naka Output of most of fruit bearing trees drastically reduced to < 5% after 2.5 years of cell tower installation.
  37. 37. Cell phones – Cigarettes of 21st century What do they have in common? Produced by Multi-Billion $ Companies Products linked to illness Industries deny any health problemCell tower radiations are even more harmfulthan cigarettes because One can not see it One can not smell it One can not move away if his house/office is near cell towers
  38. 38. Automobile industry vs Mobile industry What do they have in common? Both are required, integral part of lifestyle Automobiles create air pollution while cell phones and towers create radiation pollution What is not common? Automobile industry has accepted that it creates air pollution and people found solutions, such as, unleaded petrol, catalytic converters, CNG, Hybrid vehicles, etc. Mobile industry is still to accept health problems from cell tower radiations.
  39. 39. Automobile industry vs Mobile industry ?
  40. 40. Solutions – Better Radiation Norms With immediate affect, we should adopt safe radiationlevel as 0.1 W/m2, so power transmitted from each towermust be reduced. This will reduce coverage area. There may be some calldrops initially. People must be informed about harmful effects ofradiation and this is being done to protect them. In 1 to 2 years, the safe radiation level should be reducedto 0.01 W/m2, this will give enough time to operators toplan the network for smooth operation. Requires large number of towers with reduced outputpower, more number of repeaters, fiber optic solutions, etc. High cost for operators - not more than health of people
  41. 41. Solutions – How to meet the increased cost? Low power RF output means less heating andpower consumption, so cooling cost is reduced, lowpower solar solution can be adopted, carbon creditcan be claimed. Can increase cost per minute from Rs. 0.3 to 0.4. Govt. can reduce the license fee Can be subsidized for 1 to 2 years to recoverinvestment cost.
  42. 42. Conclusions Only thermal effects show high radiation hazard. In addition to continuous radiation from celltowers and cell phones, there is radiation fromcomputers, laptops, TV &FM towers, microwaveovens, Wi-Fi, etc., which are additive in nature. Stricter radiation norms must be enforced in India. Mobile companies should not be in the denialmode and accept that radiation causes serioushealth problems. People around the world will carryout research to come out with solutions.
  43. 43. It is said -Child is Father of the NationSo give a thought, do we really wantfuture of our nation to be deaf orsuffer from many health problems,which could have been avoided ifcertain precautionary steps weretaken on time.
  44. 44. Thank you