16 NOVEMBER 2011
Out of many global explosions in the recent past, the bloom of cell phone industry has superseded all. Today there are a whopping 5.3 billion mobile subscribers worldwide which constitutes 77 percent of the world population. India had 890.2 million mobile phone subscribers at the end of Aug 2011, and is expected to have the world’s largest subscribers (around1.159 billion) by 2013. Cell phone has had major impact on our day-to-day life including tourism, travel, business, banking and healthcare. http://www.greaterkashmir.com/news/2011/Nov/16/a-human-and-environmental-disaster-in-the-waiting–30.asp
Mobile phone, a sort of complex small radio imbedded with mini transmitter, transmit radiofrequency-waves (RF-waves) when powered on. These waves are captured by nearest tower (base-station) and thus cell phone when turned on is “always online” to receive calls and texts. The term cellular phone is derived from the “cell” principle of radio transmission. Each base station provides a single “cell” or radio-signal-span-radius. Combining all of these signals in a location makes it appear as cellular compartments. Therefore, when you change your location, you go out of a single cell and enter a new one.
When a person makes a cell phone call, a signal is sent from the phone’s antenna to the nearest base-station antenna. The base-station responds to this signal by assigning it an available RF-channel. RF-waves transfer the voice information to the base-station. The voice signals are then sent to a switching center, which transfers the call to its destination. Voice signals are then relayed back and forth during the call.
RF-waves (450-2700MHz; 0.1-2W) are electromagnetic fields and unlike ionizing radiation (X-rays, gamma-rays) can neither break chemical bonds nor cause ionization in the human body. Tissue heating is the principal mechanism of interaction between RF energy and the human body. WHO/IARC has classified RF waves as possibly carcinogenic to humans (Group 2B). By definition Group 2B carcinogen is an agent possibly carcinogenic to humans or for which there is limited evidence of carcinogenicity in humans.
Towers (base-stations) may be free standing or mounted on existing structures. Guidelines (The Environment Protection Act, 1986) for erecting towers include: base structure should be 50 to 200 feet high so that antennas can adequately cover the area; first preference to erect tower should be given to forest areas or open or public places away from residential locality; towers should not occupy premises of schools or hospitals or narrow lanes and not directly facing any building.
In case of multiple antennas, sharing of the facility should be explored. Access to tower should be prohibited: “Danger! RF-radiation, Restricted area”. If above guidelines are followed human exposure to RF-waves from towers is minimal. The energy from a tower antenna is directed toward the horizon (parallel to the ground), with some downward scatter. The amount of energy decreases rapidly with increasing distance from the antenna. As a result, the level of exposure to RF-waves at ground level is very low compared to the level close to the antenna.
Problem arises when the above guidelines are flouted. Often we see towers erected on roof tops, compounds, schools, hospitals, and trees, water tanks, within narrow lanes, inside crowded residential areas, chimneys, church steeples and flagpoles; all for monetary gains. Under such circumstances it is impossible to protect general public from RF-radiation exposure. However cell phone industry for several reasons stresses that the exposure to RF-waves, even under these circumstances is negligible. Even the Federal Communications Commission believes that RF-radiation from antennas result in exposure levels on the grounds that are typically thousands of times below safety limits. Therefore, there is no reason to believe that such towers could constitute a potential health hazard to nearby residents or students. Most experts question the validity of these explanations and would like the guidelines for erecting base stations to be implemented.
The current US standard for cell site radiation in the US is 580-1000 microwatts-per-square-centimeter. Many other countries have set levels hundreds of times lower. The reason for the disparity is that no one really knows what level of cell tower radiation is safe. Current limits have been influenced more by economic and political imperatives than by research into health and safety. More important than the intensity of radiation emitted at the tower is the strength of the resulting radiation wherever people live and work. This depends on the intensity at the source – and one’s distance from it. Different cell sites emit different amounts of radiation. Radiation levels from a single cell site vary, depending on usage. Even maintenance issues can affect how much radiation a cell site is currently producing.
Measurement with a suitable meter is the only way to know how much radiation you are receiving at a particular spot. If you detect >100 mv/m in place of your work or residence, you should be concerned. If you cannot obtain a meter, tower distance of 400 meters or more from your residence or work is probably not harmful to you.
What are the possible harmful effects of RF waves emitted by the base stations? Most of the literature driven by powerful industry on this subject state that there is no evidence that RF-waves from towers is harmful to human health and there is no published convincing evidence that this leads to any form of human cancer. They often refer amongst other to a British study on more than 1000 families which found no link between mother’s exposure to towers during pregnancy and risk of childhood cancers.
In contrast, over 100 scientists and physicians at Boston and Harvard University’s Schools of Public Health have called cell phone towers a potential radiation hazard. Experts believe that individuals differ in their response to similar levels of RF-radiation. For some people, short term effects from tower radiation exposure may include headaches, sleep disorders, poor memory, mental excitation, confusion, anxiety, depression, appetite disturbance and listlessness.
In September of 2010, 10-member committee under Bombay-Natural-History-Society (BNHS) studied the impact of towers and reviewed 919 studies performed in India and abroad; 593 showed negative impact on birds, bees, humans, wildlife and plants. They pinpointed cell phone towers as a potential cause for decline of animal populations. Committee stressed an urgent need to focus more scientific attention on the subject before it was too late.
A study into the effects of a cell tower on a herd of dairy cattle conducted in Germany showed a measurable drop in milk yield. Relocating the cattle restored the milk yield and moving them back to the original pasture recreated the problem. A human study (Kempten West) in 2007 found substantial adverse effects on many hormones in persons exposed to tower radiation.
A German study on 1000 residents living within 400 meters of towers for over 10 years found prevalence of cancer 3 times higher than the control group. Breast cancer topped the list, but cancers of the prostate, pancreas, bowel, skin melanoma, lung and blood cancer were all increased. Another study from Israel found 8 cancers in 622 residents who lived within 350 meters of a cell phone tower as against 2 cancers in 1222 control patients who lived further away. In a case known as “Towers-of-Doom”, two cell masts on a five story apartment building in London caused many health problems in residents especially those living in top floors and seven detectable cancers.
I have carefully reviewed the scientific contents of the above anecdotal reports published on the safety and/or harmful effects of cell phone towers on humans and environment. One is struck with the paucity (in amount) as well as poverty (in quality) of published literature on this vital subject. Very few studies have specifically concentrated on cancer risk from cell phone towers. This lack of studies is in itself a cause for concern, especially since anecdotal evidence is plentiful. This is because of major conflict of interest by the industry. Funding agencies of future projects are the very organizations that would be at disadvantage if definite link between cell phone towers and human and environment effects are found and that is the reason this research is going at a snail’s pace.
Consequence to this, I was not convinced by either of these studies to state that cell phone towers are safe or harmful. Thus the slogan: “Cell phone towers, as distributed now, are potential and hidden human and environmental disaster in the waiting” shall need much more scientific data to prove or disprove it. Till then most exposed to RF-radiation shall have to pass through a painful wait!
Dhadna, United Arab Emirates, Dhadna, UAE
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