Tuesday, October 12, 2010

Radiation from mobile phone towers

Radiation from mobile phone towers
During the recent period, the media, Government authorities, NGOs and the Indian Public have been raising lot of concern about the possible health hazard from the mobile phone towers due to radiation. The Government authorities in Maharashtra, Delhi and UP are active on this front and a number of mobile phone towers have been sealed by the local authorities after getting complaints on public safety from the public and NGOs. According to some media reports there is a concern that the electromagnetic RF signals emitted by these mobile phone towers cause brain cancer, brain tumor and hampers child’s growth among the people who live near the mobile towers.
In India there are around 330,000 mobile phone towers and the number is expected to grow by another 130,000 in the next 3 years. The country has already reached a tele density of 59% and there are more than 655 million mobile phone users as on August 2010 in India. The private operators are about to launch 3G services and this controversy and the action taken by the local authorities have created some setback to the aggressive network roll out by the operators.
What is a mobile phone tower?
A mobile phone tower, known as Base Transceiver Station (BTS) in the technical language, consists of tower, antenna, Diesel generator and a shelter to house air conditioner and electronic equipments. These antennas are located on towers and rooftops as it is required to be located at a height for better coverage. The electro magnetic RF signals transmitted by these antennas carry the mobile calls from one user to the other.
What is radio frequency?
Radiofrequency energy is radio waves which are used for telecommunication, radio, TV broadcasting, satellite communication and in microwave oven. Radio waves are also known as electro magnetic spectrum and the area where these waves are found is called electromagnetic field. Electromagnetic wave travels at the speed of light. The frequency of a radio wave is usually expressed in units called hertz (one wave per second), one kilohertz (one thousand waves per second), one megahertz (one million waves per second) and one gigahertz (one billion waves per second).
Accepted levels of RF exposure
The quantity used to measure how much RF energy is actually absorbed by the body is called the Specific Absorption Rate or SAR. It is usually expressed in units of watts per kilogram (W/kg). Various international organizations have developed standards for exposure to radiofrequency energy. The international agencies like National Council on Radiation Protection and Measurements (NCRP), The Institute of Electrical and Electronics Engineers (IEE), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) have identified a whole-body Specific Absorption Rate (SAR) value of 4 watts per kilogram (4 W/kg) as a threshold level of exposure at which harmful biological effects may occur. According to a study, the average level of RF exposure from the mobile phone tower is only 0.002% of the recommended guidelines.
Mobile phones also emit low levels of radio frequency energy (RF) while being used. They emit very low levels of RF even in the stand-by mode. The specific absorption rate (SAR) recommended for mobile phone is 1.6 watts per kilogram. The use of hands free kits reduces the absorption of RF energy in the head as it is kept at a distance from the body.
Media Reports
Tehelka, a weekly newspaper in India, conducted a survey in collaboration with Cogent EMR, on radiation from the mobile phone towers in Delhi.  As per this report published in June 2010, 40% of the areas surveyed are high risk areas where the radiation levels are nearly 7 times more than the safe limit and only 20% are within the safe limit. Tehelka also quoted the official guideline issued by the Delhi government and reported that these guidelines were not followed by the operators and Government authorities. As per this guideline mobile phone towers are not allowed near schools and hospitals and in narrow lanes. Antennas should be at least 3 metres away from a nearby building and 3 metres above the roof. There should be restriction to access the tower and it is mandatory to display warning signals.
The strength of RF signals is greatest at its source and reduces with distance. Large amount of RF energy can heat tissue. This can damage tissues and increase body temperatures. Very high levels of electromagnetic energy can ionize biological tissues. Ionization is a process which can permanently damage biological tissues including DNA, the genetic material. Radio frequency range required for mobile communications lies in the non-ionizing part of the spectrum and does not have enough energy to cause any genetic damage. Ionization only occurs with very high levels of electromagnetic energy such as X-rays and gamma rays
Scientific evidences show that geographically cancers are unevenly distributed among the population and not clustered around mobile phone towers. Secondly the cancer cases around the mobile towers are of different types and not restricted to specific body parts like brain. According to a WHO report no adverse short or long term health effects have been shown to occur from the RF signals produced by mobile towers. As per the report submitted by a committee formed by the Ministry of Health and Family Welfare, RF exposure from mobile phone towers are much less than from FM radio and television transmissions
The telecom operators refuse to accept that there can be any adverse effect from these mobile phone towers. COAI and AUSPI have roped in eminent academicians in order to confirm that the towers do not pose any risk.
Interestingly, there are a number of anti radiation products available in India, but the market for these products has not yet picked up despite media reports on radiation.
Government initiative
Department of Telecom has issued instructions to all Access Service Providers to conform to the limits of radiation as prescribed by International Commission on Non-ionizing Radiation Protection (ICNIRP). The government has asked service providers to have all the base transreceiver station self-certified as meeting radiation norms. The self-certification details have to be submitted to respective Telecom Enforcement Resource and Monitoring (TERM) Cells of DoT by November 15, 2010.  If any site fails to meet the Electro Magnetic Radiation criterion, a penalty of Rs. five lakh shall be levied per BTS per service provider. The Government also instructed that all new BTS sites should start radiating only after the self- certificate has been submitted to relevant TERM Cells. The Trai has proposed radiation exposure limits for mobile phone towers. Also, a committee of the TEC-the technical arm of the DoT-has been set up to study issues related to the implementation of the ICNIRP guidelines in India.
Conclusion
The Indian mobile phone industry is growing at a rapid pace. Its 650 million subscriber base is growing at the rate of 15 million every month. The industry wants to grow faster and reach its goal of 100% tele density. The industry needs a quick solution to this controversy. The verdict on radiation impact is yet out even though the scientific evidences available so far do not show a danger from either mobile phones or from mobile phone towers. However with the awareness created by media reports and Government’s proposed action to monitor the towers, it is expected that the industry will find out a solution very soon so that it can continue its growth story.

VS Moni is a

Leave a Reply

 
 
 

Additional Articles From "Mobile Phones"

Posted by at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)