Wednesday, June 15, 2011
Stricter radiation emission guidelines soon: Sachin Pilot
“We are sensitive to health-related effects of radiation emissions from mobile towers”
Alarmed by the latest World Health Organisation (WHO) report highlighting that mobile phone users may be at increased risk from brain cancer, the Centre on Saturday said it would come soon out with stricter radiation norms for mobile handsets and towers. It has also decided to devise a better mechanism to monitor radiation from towers and ensure sale of safer handsets.
“We have been sensitive to the issue of possible health-related effects of radiation emissions from mobile towers and phones. An expert group has already recommended that the government should revisit radiation guidelines for mobile towers and adopt guidelines for radiation emission by cell phones. We are working on it and soon come out with fresh guidelines to address possible health hazards from mobile towers and handsets,” Minister of State for Communications and I.T. Sachin Pilot told The Hindu.
“While telecom is a huge success story in India, we have to ensure that any possible health-related effects of radiation emitted by mobile phones and towers are reflected in the guidelines. The final guidelines would take into account the best global benchmarks and scientific evidence on the subject,” he said.
Mr. Pilot said the Department of Telecommunications was already carrying out a special drive to ensure that all mobile towers emit radiation as per prescribed limit. “Till March 31, 2011, over 5.88 lakh out of 6 lakh base stations had been self-certified to meet radiation standards. Each non-complying tower carries a penalty of Rs. 5 lakh. We have carried out necessary amendments in license conditions mandating self-certification radiation levels of towers to ensure compliance with the WHO-endorsed guidelines of International Commission for Non-ionizing Radiation Protection (ICNIRP) adopted by India,” the Minister added.
Last year, Mr. Pilot had held consultations on the subject with multiple stakeholders both in the government and the private sector. As a follow-up, the DoT had set up an Inter-Ministerial Group comprising experts from the DoT, the Ministry of Health, the Department of Biotechnology, the Ministry of Environment & Forests and the Indian Council of Medical Research, to evaluate the evidence, revisit radiation guidelines for mobile towers and adopt guidelines for radiation emission by cell phones.
In its report, Inter-Ministerial Group has recommended revision of radiation limits for mobile handsets, besides making declaration of radiation level on each mobile mandatory. For towers, it said radiation norms should be ten times stricter than the existing ones.
The WHO's International Agency for Research on Cancer (IARC) recently said radio-frequency electromagnetic fields generated by mobile handsets are “possibly carcinogenic to humans.”
The report is based on review of evidence coming from epidemiological studies pointing to an increased incidence of glioma, a malignant type of brain cancer.
Telcos scurry to conform to norms
Telcos scurry to conform to norms
Read More:World Health Organization|Jawaharlal Nehru University|Inter Ministerial Group|Girish Kumar|Department Of Telecom|Cellphone Radiation
NEW DELHI: Indian telecom companies are scurrying to conform to the government's stipulated health norms in light of growing evidence on the cancerous nature of cellphone radiation.
There has been an amendment in the Access Service Licenses — mandating self-certification radiation levels of cellphone towers — to ensure compliance with WHO-endorsed guidelines of International Commission for Non-ionizing Radiation Protection (ICNIRP). The stricture led 5, 88,645 out of 6, 05,859 base stations to get self-certification till March 31, 2011.
Speaking to TOI, Union minister of state for communications and Information Technology Sachin Pilot said non-compliance to the stipulated radiation limits carries a penalty of Rs five lakh for every mobile tower.
Talking on the cellphone could cause a malignant form of brain cancer, said International Agency for Research on Cancer (IARC) recently. It classified radiation emanating from cellphones alongside gasoline engine exhaust, lead and DDT as "possibly carcinogenic to humans".
IARC said, "The WHO/IARC has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use."
Pilot said, "We are not going to compromise with radiation limits since it has health-related concerns. The department of telecommunications set up anInter Ministerial Group in August, 2010, to evaluate the evidence, revisit radiation guidelines for mobile towers and adopt guidelines for radiation emission by cell phones. This group has recommended radiation limits more stringent than that of the United Nations."
He added, "We had called for self certification of all mobile towers. Almost 90% of the towers have completed doing so. We have extended their time frame for six more months. However, the radiation limits they are complying to are the old ones. Once new compliance levels kick in, finalized by the Department of Telecom (DoT), they will have to conform to them too."
The Inter Ministerial Group in its report made some salient recommendations about mobile handsets. The group proposed revising the limit of 2 watts per kilogram averaged over 10 grams tissue to 1.6 watts per kilogram averaged over 1 gram tissue. It also called for mandatory declaration of radiation level on each mobile handset. As far as mobile towers are concerned they recommended radiation norms which are ten times as strict as the existing ones- from f/200 watts per square meter to f/2000 watts per square meter.
The group said mobile towers should not be installed near high density residential areas, schools, playgrounds and hospitals.
"The localized specific absorption rate (SAR) value as per the Indian guidelines is 2 watt per kg, averaged over a six minute period and using a 10 gram average mass. With higher SAR — a measure of the amount of radiofrequency energy absorbed by the body while using a phone of mobile handsets — the public could potentially receive much higher radiofrequency exposure. We have recommended that SAR levels to be lowered to 1.6 watt/kg, as prescribed by the Federal Communication Commission of US," said experts.
Girish Kumar, professor in department of electrical engineering at IIT Bombay, whose research on hazards of cellphone use was taken as a reference for the committee decision, said, "There is a 40% increase in the risk of brain cancer among teenagers using cell phones for long periods. The younger the child, the deeper is the penetration of electromagnetic radiation as children's skulls are thinner."
Another Jawaharlal Nehru University study found that the exposure to radiation from mobile towers and cellphones could have an adverse impact on male fertility and pose health hazards by depleting the defence mechanism of cells. The report also suggested that children, adolescents and pregnant women should avoid excessive use of cellphones. People should use hands-free technologies to minimize the contact of the head with cellphone. "People having active medical implants should keep their cellphone at least 30 cm away from the implant," it added.
There has been an amendment in the Access Service Licenses — mandating self-certification radiation levels of cellphone towers — to ensure compliance with WHO-endorsed guidelines of International Commission for Non-ionizing Radiation Protection (ICNIRP). The stricture led 5, 88,645 out of 6, 05,859 base stations to get self-certification till March 31, 2011.
Speaking to TOI, Union minister of state for communications and Information Technology Sachin Pilot said non-compliance to the stipulated radiation limits carries a penalty of Rs five lakh for every mobile tower.
Talking on the cellphone could cause a malignant form of brain cancer, said International Agency for Research on Cancer (IARC) recently. It classified radiation emanating from cellphones alongside gasoline engine exhaust, lead and DDT as "possibly carcinogenic to humans".
IARC said, "The WHO/IARC has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use."
Pilot said, "We are not going to compromise with radiation limits since it has health-related concerns. The department of telecommunications set up anInter Ministerial Group in August, 2010, to evaluate the evidence, revisit radiation guidelines for mobile towers and adopt guidelines for radiation emission by cell phones. This group has recommended radiation limits more stringent than that of the United Nations."
He added, "We had called for self certification of all mobile towers. Almost 90% of the towers have completed doing so. We have extended their time frame for six more months. However, the radiation limits they are complying to are the old ones. Once new compliance levels kick in, finalized by the Department of Telecom (DoT), they will have to conform to them too."
The Inter Ministerial Group in its report made some salient recommendations about mobile handsets. The group proposed revising the limit of 2 watts per kilogram averaged over 10 grams tissue to 1.6 watts per kilogram averaged over 1 gram tissue. It also called for mandatory declaration of radiation level on each mobile handset. As far as mobile towers are concerned they recommended radiation norms which are ten times as strict as the existing ones- from f/200 watts per square meter to f/2000 watts per square meter.
The group said mobile towers should not be installed near high density residential areas, schools, playgrounds and hospitals.
"The localized specific absorption rate (SAR) value as per the Indian guidelines is 2 watt per kg, averaged over a six minute period and using a 10 gram average mass. With higher SAR — a measure of the amount of radiofrequency energy absorbed by the body while using a phone of mobile handsets — the public could potentially receive much higher radiofrequency exposure. We have recommended that SAR levels to be lowered to 1.6 watt/kg, as prescribed by the Federal Communication Commission of US," said experts.
Girish Kumar, professor in department of electrical engineering at IIT Bombay, whose research on hazards of cellphone use was taken as a reference for the committee decision, said, "There is a 40% increase in the risk of brain cancer among teenagers using cell phones for long periods. The younger the child, the deeper is the penetration of electromagnetic radiation as children's skulls are thinner."
Another Jawaharlal Nehru University study found that the exposure to radiation from mobile towers and cellphones could have an adverse impact on male fertility and pose health hazards by depleting the defence mechanism of cells. The report also suggested that children, adolescents and pregnant women should avoid excessive use of cellphones. People should use hands-free technologies to minimize the contact of the head with cellphone. "People having active medical implants should keep their cellphone at least 30 cm away from the implant," it added.
Thursday, June 2, 2011
Mobile phone users may be at increased risk from brain cancer
Times of India Dt. 01.06.11 (Mumbai Edition)
PARIS: Mobile phone users may be at increased risk from brain cancer and should use texting and free-hands devices to reduce exposure, the World Health Organisation's cancer experts said.
Radio-frequency electromagnetic fields generated by such devices are "possibly carcinogenic to humans," the International Agency for Research on Cancer (IARC) announced at the end of an eight-day meeting in Lyon, France.
Experts "reached this classification based on review of the human evidence coming from epidemiological studies" pointing to an increased incidence of glioma, a malignant type of brain cancer, said Jonathan Samet, president of the work group.
Two studies in particular, the largest conducted over the last decade, showed a higher risk "in those that had the most intensive use of such phones," he said in a telephone news conference.
Some individuals tracked in the studies had used their phones for an average of 30 minutes per day over a period of 10 years.
"We simply don't know what might happen as people use their phones over longer time periods, possibly over a lifetime," Samet said.
There are about five billion mobile phones registered in the world. The number of phones and the average time spent using them have both climbed steadily in recent years.
The CTIA-The Wireless Association dismissed the report saying the UN agency "conducts numerous reviews and in the past has given the same score to, for example, pickled vegetables and coffee."
This classification "does not mean cell phones cause cancer," the industry association said in a statement, noting that "limited evidence from statistical studies can be found even though bias and other data flaws may be the basis for the results."
The IARC cautioned that current scientific evidence showed only a possible link, not a proven one, between wireless devices and cancers.
"There is some evidence of increased risk of glioma" and another form of non-malignant tumour called acoustic neuroma, said Kurt Straif, the scientist in charge of editing the IARC reports on potentially carcinogenic agents.
"But it is not at the moment clearly established that the use of mobile phones does in fact cause cancer in humans," he said.
The IARC does not issue formal recommendations, but experts pointed to a number of ways consumers can reduce risk.
"What probably entails some of the highest exposure is using your mobile for voice calls," Straif said.
"If you use it for texting, or as a hands-free set for voice calls, this is clearly lowering the exposure by at least an order of magnitude," or by tenfold, he said.
A year ago the IARC concluded that there was no link between cell phones and brain cancer, but that earlier report was criticised as based on data that was out of date.
The new review, conducted by a panel of 31 scientists from 14 countries, was reached on the basis of a "full consensus," said Robert Baan, in charge of the written report, yet to be released.
"This is the first scientific evaluation of all the literature published on the topic with regard to increased risk of cancer," he said.
But the panel stressed the need for more research, pointing to incomplete data, evolving technology and changing consumer habits.
"There's an improvement in the technology in terms of lower emissions but at the same time we see increased use, so it is hard to know how the two balance out," Baan noted.
The IARC ranks potentially cancer-causing elements as carcinogenic, probably carcinogenic, possibly carcinogenic or "probably not carcinogenic". It can also determine that a material is "not classifiable".
Cigarettes, sunbeds and asbestos, for example, fall in "Group 1", the top threat category. Cell phones now join glass wool and gasoline exhaust in Group 2B as "possibly carcinogenic".
Industry groups reacted cautiously, pointing to other common consumer items -- including coffee and vegetables pickled in chemicals -- that are included in the same category.
"In France, the health ministry already applies a precautionary approach to cellphones because it considers that no danger has been established, that doubts remain and, thus, that more research is needed," the French Federation of Telecoms said in a statement.
Some consumer advocacy groups said the new classification was overdue.
"As of today, no one can say the risk does not exist, and now everyone -- politicians, telecoms, employers, consumers and parents -- have to take this into account," said Janine Le Calvez, head of PRIARTEM, a consumer advocacy group concerned with cell phone safety.
Radio-frequency electromagnetic fields generated by such devices are "possibly carcinogenic to humans," the International Agency for Research on Cancer (IARC) announced at the end of an eight-day meeting in Lyon, France.
Experts "reached this classification based on review of the human evidence coming from epidemiological studies" pointing to an increased incidence of glioma, a malignant type of brain cancer, said Jonathan Samet, president of the work group.
Two studies in particular, the largest conducted over the last decade, showed a higher risk "in those that had the most intensive use of such phones," he said in a telephone news conference.
Some individuals tracked in the studies had used their phones for an average of 30 minutes per day over a period of 10 years.
"We simply don't know what might happen as people use their phones over longer time periods, possibly over a lifetime," Samet said.
There are about five billion mobile phones registered in the world. The number of phones and the average time spent using them have both climbed steadily in recent years.
The CTIA-The Wireless Association dismissed the report saying the UN agency "conducts numerous reviews and in the past has given the same score to, for example, pickled vegetables and coffee."
This classification "does not mean cell phones cause cancer," the industry association said in a statement, noting that "limited evidence from statistical studies can be found even though bias and other data flaws may be the basis for the results."
The IARC cautioned that current scientific evidence showed only a possible link, not a proven one, between wireless devices and cancers.
"There is some evidence of increased risk of glioma" and another form of non-malignant tumour called acoustic neuroma, said Kurt Straif, the scientist in charge of editing the IARC reports on potentially carcinogenic agents.
"But it is not at the moment clearly established that the use of mobile phones does in fact cause cancer in humans," he said.
The IARC does not issue formal recommendations, but experts pointed to a number of ways consumers can reduce risk.
"What probably entails some of the highest exposure is using your mobile for voice calls," Straif said.
"If you use it for texting, or as a hands-free set for voice calls, this is clearly lowering the exposure by at least an order of magnitude," or by tenfold, he said.
A year ago the IARC concluded that there was no link between cell phones and brain cancer, but that earlier report was criticised as based on data that was out of date.
The new review, conducted by a panel of 31 scientists from 14 countries, was reached on the basis of a "full consensus," said Robert Baan, in charge of the written report, yet to be released.
"This is the first scientific evaluation of all the literature published on the topic with regard to increased risk of cancer," he said.
But the panel stressed the need for more research, pointing to incomplete data, evolving technology and changing consumer habits.
"There's an improvement in the technology in terms of lower emissions but at the same time we see increased use, so it is hard to know how the two balance out," Baan noted.
The IARC ranks potentially cancer-causing elements as carcinogenic, probably carcinogenic, possibly carcinogenic or "probably not carcinogenic". It can also determine that a material is "not classifiable".
Cigarettes, sunbeds and asbestos, for example, fall in "Group 1", the top threat category. Cell phones now join glass wool and gasoline exhaust in Group 2B as "possibly carcinogenic".
Industry groups reacted cautiously, pointing to other common consumer items -- including coffee and vegetables pickled in chemicals -- that are included in the same category.
"In France, the health ministry already applies a precautionary approach to cellphones because it considers that no danger has been established, that doubts remain and, thus, that more research is needed," the French Federation of Telecoms said in a statement.
Some consumer advocacy groups said the new classification was overdue.
"As of today, no one can say the risk does not exist, and now everyone -- politicians, telecoms, employers, consumers and parents -- have to take this into account," said Janine Le Calvez, head of PRIARTEM, a consumer advocacy group concerned with cell phone safety.
Wednesday, June 1, 2011
Write -Up by A M JOSHI; Need for more than 3 m seperation bet. Tower and next Bldg.
From: Ashok Joshi
Date: Sun, May 29, 2011 at 6:42 PM
Subject: Write -Up by A M JOSHI; Need for more than 3 m seperation bet. Tower and next Bldg.
To: amjoshi7@gmail.com
Subject: Write -Up by A M JOSHI; Need for more than 3 m seperation bet. Tower and next Bldg.
[ Possible Arguments to counter W B & Other State Govt.'s 3m separation stipulation / Rules ]
1. In the situation described , let us assume that the Centre of the Antenna is 1.5 m above the 3 m clearance from roof top / terrace top i. e. the Centre is 4.5 m above the terrace /roof top. Horizontal seperation for nearby building [ assuming of similar height ] is 3 m. Hence, from the geometry of right angle triangle, the distance from the centre of antenna to the adjoining building edge will be square root of 4.5 m square plus 3m square i. e. say approx. 5.4 m
2. Radiation from the cell tower
A GSM900 base station antenna transmits in the frequency range of 935 - 960 MHz. This frequency band of 25 MHz is divided into twenty sub-bands of 1.2 MHz, which are allocated to various operators. There may be several carrier frequencies (1 to 5) allotted to one operator with upper limit of 6.2 MHz bandwidth. Each carrier frequency may transmit 10 to 20W of power. So, one operator may transmit 50 to 100W of power [ at any instant ] and there may be 3-4 operators on the same roof top or tower, thereby total transmitted power may be 200 to 400W. In addition, directional antennas are used, which typically may have a gain of around 17 dB (numeric value is 50), so effectively, several KW of power may be transmitted in the main beam direction. Operators are now also assigned frequencies in 1800 MHz band , in addition to 900 MHz band.
2.1 Radiated power density from the cell tower
Power density Pd at a distance R is given by the following formula [ available in text books also ]
Pd = Pt X Gt divided by 4 X 3.14 ( i. e. Pi ) X R square
where, Pt = Transmitter power in Watts
Gt = Gain of transmitting antenna
R = Distance from the antenna in meters
For Pt = 20 W, Gt = 17 dB = 50 ( In numerical terms ) , Pd for various values of R is given in Table 1 below.
Table 1 – Power density at various distances from the transmitting tower
Distance R (m) Power density Power density
Pd in W/ square m Pd in 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 0.318 31,800
100 0.008 7,960
500 0.000318 318
The power density values given in Table 1 are for a single carrier and a single operator.
Multiple carriers are being used and multiple operators are present on the same roof top or tower,
then the above values will increase manifold. Assuming 5 carriers are used at a time by an operator --not uncommon in metro cities due to heavy traffic --- the value of Pd at 10 m will be 3.98 W/m2 . For three operators it will be 3 times say 11.98 W / m2 say 12 W / square meters. At any given tower, all the operators main beam is generally expected to be in the same direction to cover a specific road /colony etc.
2.2 At present , India [ Dot ] follow the International Commission on Non-Ionising Radiation Protection (ICNIRP) guidelines for Radiation,[ from radio wave transmitters on earth's surface ] which allow a radiation rate of 4.5 watts/sq metre at 900 MHz and 9.2 watts/sq metre at 1,800 MHz to be emitted from cell phone towers . (Inter-ministerial Committee --IMC Report, pp 31-32). India follows the latter reference level. The Dot has issued a rule in this regard ,a couple of years back , which hardly any practical value to a common man ] The ICNIRP limit has a serious flaw. It specifies this limit for only 6 minutes continuous exposure. In practice , the Cell Tower radiation is round the clock for 365 days of year ! hence, much lower limit is called for . Unfortunately , the Indian Medical Council of Research [ ICMR ] has not acted in this area effectively. As the tower has many directional antennas , transmitters etc. only actual measurement will allay any doubt of radiation in the vicinity as precise calculations will be difficult and will not give mental satisfaction. Below the tower , there is less problem , but in the nearby building esp. those who are at near tower height or just below, are the worst exposed. This value of of 12 W/m2 at 10 m is very high compared to ICNIRP stipulation indicated below [ ref. IMC Report , page 29 ,para 5.1 ]
India has adopted the following ICNIRP guidelines for basic restrictions and reference levels for limiting Electromagnetic fields exposure in the band upto 2000 MHz is f / 200 W /m2 where f is the frequency in MHz. This is 4.5 W /m2 at 900 MHz band and 9 W /m2 at 1800 MHz band. These guidelines are based on short term exposure of 6 minutes and not H24 / 365 days exposure encountered in Cell Tower radiation exposure.
2.2.1 Following the outcry reg . cell towers radiation health hazard over last few years, the DOT appointed an Inter Ministerial Committee [ IMC ] with rep. of Min. of Health , Environment also. The latter Ministries forced the Dot rep. in the IMC to agree to lower the limit by 10 times but it it is still to be notified by Govt.
The IMC Report [ year 2010 ] also addresses health hazard from cell phone handsets also besides Cell Tower Radiation Hazard ] The IMC 's suggested that the radio frequency exposure limits in India may be lowered to 1/10th of the existing reference level. They have however not given any cogent reasoning how and why they thought of 1/10 . Possibly this was a thumb rule compromise in the IMC .
2.3 The Inter Ministerial Committee of the Govt. of India ( IMC) has also accepted that the existing standards are based on thermal (heating) limits and do not address non-thermal (or low intensity) exposures which are reported to cause Biological effects. Lot of other medical reports are also available pointing to the need for lowering the ICNIRP guidelines. The IMC has also stated that the present ICNIRP / FCC ( USA ) limits are insufficiently protective of public health and require reconsideration and has recommended lowering the above limit by a factor of 10. It has also referred to the Bio-initiative report, [ published in USA in 2007 ] which has recommended 1000 microwatt/m^2=0.001W/m^2 for outdoor exposure and 100 microwatt/m^2 for continuous indoor exposure [ pl see Section 5.4, page 32 of IMC Report ]
2.4 One should also take note of see the limits lower by 100 or more time times adopted by many other countries [ ref. page 30 of IMC Report and Prof. Kumar's doc ] . China has adopted 0.4 W /m2 standard , 0.1 W / m2 by Poland / Hungary ,Paris and 0.001 W/m2 . These countries must have done this after careful consideration of Health hazards from radiation exposure.
2.5 Radiation pattern of the antenna
It is accepted that the , radiation density will be much lower in the direction away from the main beam and the above mentioned scenario may not be encountered for an adjoining building , every time. The simulated radiation pattern of GSM900 antenna of approximately 17 dB gain at 950 MHz of size 2400 mm x 30 mm is shows radiation in two planes – horizontal and vertical. There is one main lobe and several side lobes. For the main lobe, half-power beam-width (HPBW – defined as angular range over which maximum power decreases to half of its value) in the horizontal direction is 65 degrees and HPBW in the vertical direction is 6 degrees. There are several side lobes, whose maximum levels are about -13 to -20 dB below the main level.
One should know actual radiation pattern of the antenna (which unfortunately is not made public) to calculate exact radiation density at a point , but the above formula can give reasonable estimation. One cannot go on doing calculations for each tower and each building . Again estimating actual radiation pattern , integrating patterns for the antenne of 3-4 operators will also be a complex task Actual measurements would be desirable but may not be practicable , every time .
2.5.1 One should be aware that compliance with present standards is left by the DoT to self certification by the service providers. Even this is not being done and a large number of towers are unauthorised – illegal. As the Tower no. in India has crossed 5.88 lakhs , this a real serious problem which needs attention of Policy Makers / Ministers.
The DoT had invited comments from stake holders on the IMC Report by 31st March 2011. Final decision on this proposal of lowering the limits is awaited. But all such reforms will be on paper only because the DoT has no manpower to verify conformity. Public outcry should force the service provider to carry out measurements in the presence of enlightened public rep.s
3. International Telecommunication Union ( ITU ) , Geneva , Recommendation
The ITU - T Rec. K.52 on Guidance on complying with limits for human exposure to electromagnetic fields is also important . In Appendix II --p. 25 , 26 etc. , examples of simple evaluation of EMF exposure at ground level and at an adjacent buildings are given. From the curves , given therein ; it is apparent that maximum exposure hazard is there for horizontal separation upto about 10 -15 meters .
4. Case study of Usha Kiran Building, Mumbai
Through the help of the above typical radiation pattern, Prof. G. Kumar has analyzed the news reported in Mid- day, Mumbai dated Jan. 3, 2010, which stated - “Mumbai's swanky Usha Kiran building says the four cancer cases there could be linked to mobile towers installed on the facing Vijay Apartments . The towers are seperated by more than 10 -15 metes from this building . People living in the 6th, 7th and 8th floor in the opposite building [ Ushakiran ] will get maximum radiation as they are in the main beam direction. People living on the other floors will receive lesser radiation as beam maxima is reduced considerably as can be observed from vertical radiation pattern. In the horizontal direction again, people living in the front side of the antenna will receive much higher radiation compared topeople living in the back side of antenna.
http://www.mid-day.com/news/2010/jan/030110-mobile-tower-cancer-cases-carmichael-road-posh-areas.htm
From Table 1, it may be noted that for a single transmitter, power density at R = 50m is equal to 0.0318W/m2 = 31,800 µW/m2. Even for 3 transmitters in the same direction, it comes out to be approximately 0.1 W/m2 = 100,000 µW/m2, which has caused cancer to several people in a duration of 2 to 3 years.
4. 1. Measurement at a cancer’s patient residence [ From Prof. G Kumar's Report ]
Since the radiation effect on the human body is cumulative, a hand held broadband radiation monitor (Frequency range of 800 to 2500 MHz) has been developed to measure the total received power. Radiation measurements were carried out in a lady’s apartment, who had developed cancer within one year of installation of cell tower. The layout of the apartment . The measured readings show that the radiation level is very high and it is between – 4 to -10 dBm. At 900 MHz, -10 dBm received power is equivalent to 7,068 µW/m2, again implying that safe radiation norms must be reduced considerably than adopted by India, which is 4.7W/m2 = 4,700,000 µW/m2.
5. It is hoped that the above , will make it apparent that the if 3m separation specified in W. B . / Maharashtra / Delhi Govt. Notification / Rules is NOT Safe for human exposure to Cell Tower radiation. It is particularly harmful when one is exposed to main beam. The 3m seperation distance specified in W.B Govt. and other State Govt. 's Notification / Rules is not adequate to protect the residents in nearby buildings and in such matters caution would be a better option. It took many years for the Govt. to ban Smoking in public places and to ban the use of Asbestos. Let us not repeat this in case of cell Tower radiation exposure.
Date: Sun, May 29, 2011 at 6:42 PM
Subject: Write -Up by A M JOSHI; Need for more than 3 m seperation bet. Tower and next Bldg.
To: amjoshi7@gmail.com
Subject: Write -Up by A M JOSHI; Need for more than 3 m seperation bet. Tower and next Bldg.
[ Possible Arguments to counter W B & Other State Govt.'s 3m separation stipulation / Rules ]
1. In the situation described , let us assume that the Centre of the Antenna is 1.5 m above the 3 m clearance from roof top / terrace top i. e. the Centre is 4.5 m above the terrace /roof top. Horizontal seperation for nearby building [ assuming of similar height ] is 3 m. Hence, from the geometry of right angle triangle, the distance from the centre of antenna to the adjoining building edge will be square root of 4.5 m square plus 3m square i. e. say approx. 5.4 m
2. Radiation from the cell tower
A GSM900 base station antenna transmits in the frequency range of 935 - 960 MHz. This frequency band of 25 MHz is divided into twenty sub-bands of 1.2 MHz, which are allocated to various operators. There may be several carrier frequencies (1 to 5) allotted to one operator with upper limit of 6.2 MHz bandwidth. Each carrier frequency may transmit 10 to 20W of power. So, one operator may transmit 50 to 100W of power [ at any instant ] and there may be 3-4 operators on the same roof top or tower, thereby total transmitted power may be 200 to 400W. In addition, directional antennas are used, which typically may have a gain of around 17 dB (numeric value is 50), so effectively, several KW of power may be transmitted in the main beam direction. Operators are now also assigned frequencies in 1800 MHz band , in addition to 900 MHz band.
2.1 Radiated power density from the cell tower
Power density Pd at a distance R is given by the following formula [ available in text books also ]
Pd = Pt X Gt divided by 4 X 3.14 ( i. e. Pi ) X R square
where, Pt = Transmitter power in Watts
Gt = Gain of transmitting antenna
R = Distance from the antenna in meters
For Pt = 20 W, Gt = 17 dB = 50 ( In numerical terms ) , Pd for various values of R is given in Table 1 below.
Table 1 – Power density at various distances from the transmitting tower
Distance R (m) Power density Power density
Pd in W/ square m Pd in 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 0.318 31,800
100 0.008 7,960
500 0.000318 318
The power density values given in Table 1 are for a single carrier and a single operator.
Multiple carriers are being used and multiple operators are present on the same roof top or tower,
then the above values will increase manifold. Assuming 5 carriers are used at a time by an operator --not uncommon in metro cities due to heavy traffic --- the value of Pd at 10 m will be 3.98 W/m2 . For three operators it will be 3 times say 11.98 W / m2 say 12 W / square meters. At any given tower, all the operators main beam is generally expected to be in the same direction to cover a specific road /colony etc.
2.2 At present , India [ Dot ] follow the International Commission on Non-Ionising Radiation Protection (ICNIRP) guidelines for Radiation,[ from radio wave transmitters on earth's surface ] which allow a radiation rate of 4.5 watts/sq metre at 900 MHz and 9.2 watts/sq metre at 1,800 MHz to be emitted from cell phone towers . (Inter-ministerial Committee --IMC Report, pp 31-32). India follows the latter reference level. The Dot has issued a rule in this regard ,a couple of years back , which hardly any practical value to a common man ] The ICNIRP limit has a serious flaw. It specifies this limit for only 6 minutes continuous exposure. In practice , the Cell Tower radiation is round the clock for 365 days of year ! hence, much lower limit is called for . Unfortunately , the Indian Medical Council of Research [ ICMR ] has not acted in this area effectively. As the tower has many directional antennas , transmitters etc. only actual measurement will allay any doubt of radiation in the vicinity as precise calculations will be difficult and will not give mental satisfaction. Below the tower , there is less problem , but in the nearby building esp. those who are at near tower height or just below, are the worst exposed. This value of of 12 W/m2 at 10 m is very high compared to ICNIRP stipulation indicated below [ ref. IMC Report , page 29 ,para 5.1 ]
India has adopted the following ICNIRP guidelines for basic restrictions and reference levels for limiting Electromagnetic fields exposure in the band upto 2000 MHz is f / 200 W /m2 where f is the frequency in MHz. This is 4.5 W /m2 at 900 MHz band and 9 W /m2 at 1800 MHz band. These guidelines are based on short term exposure of 6 minutes and not H24 / 365 days exposure encountered in Cell Tower radiation exposure.
2.2.1 Following the outcry reg . cell towers radiation health hazard over last few years, the DOT appointed an Inter Ministerial Committee [ IMC ] with rep. of Min. of Health , Environment also. The latter Ministries forced the Dot rep. in the IMC to agree to lower the limit by 10 times but it it is still to be notified by Govt.
The IMC Report [ year 2010 ] also addresses health hazard from cell phone handsets also besides Cell Tower Radiation Hazard ] The IMC 's suggested that the radio frequency exposure limits in India may be lowered to 1/10th of the existing reference level. They have however not given any cogent reasoning how and why they thought of 1/10 . Possibly this was a thumb rule compromise in the IMC .
2.3 The Inter Ministerial Committee of the Govt. of India ( IMC) has also accepted that the existing standards are based on thermal (heating) limits and do not address non-thermal (or low intensity) exposures which are reported to cause Biological effects. Lot of other medical reports are also available pointing to the need for lowering the ICNIRP guidelines. The IMC has also stated that the present ICNIRP / FCC ( USA ) limits are insufficiently protective of public health and require reconsideration and has recommended lowering the above limit by a factor of 10. It has also referred to the Bio-initiative report, [ published in USA in 2007 ] which has recommended 1000 microwatt/m^2=0.001W/m^2 for outdoor exposure and 100 microwatt/m^2 for continuous indoor exposure [ pl see Section 5.4, page 32 of IMC Report ]
2.4 One should also take note of see the limits lower by 100 or more time times adopted by many other countries [ ref. page 30 of IMC Report and Prof. Kumar's doc ] . China has adopted 0.4 W /m2 standard , 0.1 W / m2 by Poland / Hungary ,Paris and 0.001 W/m2 . These countries must have done this after careful consideration of Health hazards from radiation exposure.
2.5 Radiation pattern of the antenna
It is accepted that the , radiation density will be much lower in the direction away from the main beam and the above mentioned scenario may not be encountered for an adjoining building , every time. The simulated radiation pattern of GSM900 antenna of approximately 17 dB gain at 950 MHz of size 2400 mm x 30 mm is shows radiation in two planes – horizontal and vertical. There is one main lobe and several side lobes. For the main lobe, half-power beam-width (HPBW – defined as angular range over which maximum power decreases to half of its value) in the horizontal direction is 65 degrees and HPBW in the vertical direction is 6 degrees. There are several side lobes, whose maximum levels are about -13 to -20 dB below the main level.
One should know actual radiation pattern of the antenna (which unfortunately is not made public) to calculate exact radiation density at a point , but the above formula can give reasonable estimation. One cannot go on doing calculations for each tower and each building . Again estimating actual radiation pattern , integrating patterns for the antenne of 3-4 operators will also be a complex task Actual measurements would be desirable but may not be practicable , every time .
2.5.1 One should be aware that compliance with present standards is left by the DoT to self certification by the service providers. Even this is not being done and a large number of towers are unauthorised – illegal. As the Tower no. in India has crossed 5.88 lakhs , this a real serious problem which needs attention of Policy Makers / Ministers.
The DoT had invited comments from stake holders on the IMC Report by 31st March 2011. Final decision on this proposal of lowering the limits is awaited. But all such reforms will be on paper only because the DoT has no manpower to verify conformity. Public outcry should force the service provider to carry out measurements in the presence of enlightened public rep.s
3. International Telecommunication Union ( ITU ) , Geneva , Recommendation
The ITU - T Rec. K.52 on Guidance on complying with limits for human exposure to electromagnetic fields is also important . In Appendix II --p. 25 , 26 etc. , examples of simple evaluation of EMF exposure at ground level and at an adjacent buildings are given. From the curves , given therein ; it is apparent that maximum exposure hazard is there for horizontal separation upto about 10 -15 meters .
4. Case study of Usha Kiran Building, Mumbai
Through the help of the above typical radiation pattern, Prof. G. Kumar has analyzed the news reported in Mid- day, Mumbai dated Jan. 3, 2010, which stated - “Mumbai's swanky Usha Kiran building says the four cancer cases there could be linked to mobile towers installed on the facing Vijay Apartments . The towers are seperated by more than 10 -15 metes from this building . People living in the 6th, 7th and 8th floor in the opposite building [ Ushakiran ] will get maximum radiation as they are in the main beam direction. People living on the other floors will receive lesser radiation as beam maxima is reduced considerably as can be observed from vertical radiation pattern. In the horizontal direction again, people living in the front side of the antenna will receive much higher radiation compared topeople living in the back side of antenna.
http://www.mid-day.com/news/2010/jan/030110-mobile-tower-cancer-cases-carmichael-road-posh-areas.htm
From Table 1, it may be noted that for a single transmitter, power density at R = 50m is equal to 0.0318W/m2 = 31,800 µW/m2. Even for 3 transmitters in the same direction, it comes out to be approximately 0.1 W/m2 = 100,000 µW/m2, which has caused cancer to several people in a duration of 2 to 3 years.
4. 1. Measurement at a cancer’s patient residence [ From Prof. G Kumar's Report ]
Since the radiation effect on the human body is cumulative, a hand held broadband radiation monitor (Frequency range of 800 to 2500 MHz) has been developed to measure the total received power. Radiation measurements were carried out in a lady’s apartment, who had developed cancer within one year of installation of cell tower. The layout of the apartment . The measured readings show that the radiation level is very high and it is between – 4 to -10 dBm. At 900 MHz, -10 dBm received power is equivalent to 7,068 µW/m2, again implying that safe radiation norms must be reduced considerably than adopted by India, which is 4.7W/m2 = 4,700,000 µW/m2.
5. It is hoped that the above , will make it apparent that the if 3m separation specified in W. B . / Maharashtra / Delhi Govt. Notification / Rules is NOT Safe for human exposure to Cell Tower radiation. It is particularly harmful when one is exposed to main beam. The 3m seperation distance specified in W.B Govt. and other State Govt. 's Notification / Rules is not adequate to protect the residents in nearby buildings and in such matters caution would be a better option. It took many years for the Govt. to ban Smoking in public places and to ban the use of Asbestos. Let us not repeat this in case of cell Tower radiation exposure.
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