Mobility

February 7, 2007
Radiation hazards of mobile handsets: Intense study required

Col. R. Narayanan

CHENNAI -- Professor Henry Lai, Department of Bioengineering, University of Washington, asserts more than eighty percent of energy emitted by mobile phone is absorbed by hand and head of user. The energy absorbed, apparently, can cause biological effects. About half of the published studies on biological effects of mobile phone radiation showed effects. These include genetic damage, changes in cellular and molecule functions, psychological effects, etc. Some of these effects could be hazardous to health, particularly, after long-tem repeated exposure. Mechanism of interaction of magnetic fields with human biological systems is not well understood. The most obvious mechanism is tissue heating. But, there are studies reporting substantial heating effects at energy levels, which are not high.

There are number of studies on humans relating to brain cancer development. behavioral performance, etc. Most epidemiological studies found no significant increase in brain cancer in mobile phone users. Studies showed changes in psychological performance in humans after exposure to mobile phone radiation. Professor Lai recommends phone users to minimise exposure to radiation.

Dr Donald A Redelmeir, senior scientist and director, Institute for Clinical Evaluative services, University of Toronto, informs that risk of driving while talking on cell phone is similar to hazard associated with driving with blood alcohol level at legal limit. Drivers using cell phones are four to five hundred percent more likely to get into traffic accidents than those who do not use them.

Nanda Huizing, Global Communications Department, Philips Consumer Electronics, assures that Philips manufactures mobile phones within applicable and relevant set safety standards. Philips is part of Mobile Manufacturers Forum, a grouping of mobile phone companies, which supports independent research.

A committee, headed by Dr. N.K. Ganguly, director general of Indian Council of Medical Research (ICMR), has opined that radiations from base stations installed on buildings do not pose direct health hazards to humans. As a precautionary measure, it has recommended adoption of guidelines laid by International Commission on Non-Ionising Radiation Protection to limit RF exposure.

Dr. Zenon Sienkiewicz, Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Radiation Protection Division, Oxfordshire, UK, an expert on effects of RF fields and member of groups concerned with biological and health effects of RF fields, asserts that fraction of RF field emitted by mobile phone can be absorbed by head, resulting in slight warming of skin and other superficial tissues. Although this interaction is consistent with heating properties of RF fields, a property exploited in clinical diathermy or in microwave ovens, amount of heating that mobile phone can produce is small. It has been calculated that increase in temperature of outer surfaces of brain from phone radiation is only about a tenth of one degree or so, which is considered biologically trivial ( brain experiences daily temperature fluctuation of one degree or so).

Exposures that do not cause significant heating in short-term are considered to be without any adverse effects in the long-term. Exposure guidelines are based on restricting absorbed power to limit increase in body temperature or parts of it. However some scientists have suggested that "non-thermal" interactions may occur at levels too low to cause any significant heating. At the moment it is not possible to say that such interactions do occur, but neither is it possible to completely rule them out, although they may seem very unlikely for a number of reasons.

Studies have been undertaken exploring possible effects of exposure to RF fields from mobile phones on humans. This includes long-term health risks associated with mobile phone use (epidemiological studies) and short-term physiological effects (experimental studies). Advisory Group on Non-ionising Radiation has comprehensively reviewed the relevant literature.

Although no hard evidence of adverse effects has emerged so far, this remains a very controversial topic and the subject of much scientific debate. Unfortunately, we do not have complete data on all possible health effects, and the technology is rapidly changing (from analog to digital signals, and to 3G and beyond). However, the only established adverse effect remains the distraction caused by mobile phone conversations on driving performance (in the UK, using a hand held phone whilst driving is an offence.) There have been various reports of other field-related effects, but these have generally proved difficult to replicate by other scientists.

Presently epidemiological evidence suggests that mobile phones do not increase the risk of tumour of head or neck, although we know that cancers take 15 years or more to develop following the event that caused them, and relatively few people have yet used mobile phones for that length of time, so continued investigation is required. Also the question of whether children are at greater risk remains unanswered.

Dr. Sienkiewicz assures mobile community will understand the scope and magnitude of health risks in the next few years, as results from national and international research programs, such as the Mobile Telecommunications and Health Research Program in the UK, and world-wide Interphone project, are published. These programs were set up few years ago to answer questions and concerns about mobile phones. Hopefully, a clearer understanding will come with this new knowledge. Also the World Health Organization (WHO) is expected to produce a detailed review of the subject in the next few years.

Dr. Ashok Agarwal, director, Andrology Laboratory and Reproductive Tissue Bank:; Director, Reproductive Research Center; Professor, Cleveland Clinic Lerner College of Medicine

Case Western Reserve University; Staff, Glickman Urological Institute, and Departments of Obstetrics/Gynecology, Anatomic Pathology, and Immunology, Cleveland Clinic Foundation, USA, affirms electro magnetic fields emitted by mobile phones interact with human biological systems. Electromagnetic waves (EMW) can affect human biological systems possibly via three mechanisms; EMW specific effect, thermal molecular effect or combination of these. These effects are greater at higher frequencies. Research literature contains many reports of potential adverse effects of radiofrequency EMW on the brain, heart, endocrine system and DNA of humans. Electromagnetic waves alter brain EEG activity and cause disturbances in sleep, difficulty in concentration, fatigue and headache, and increase reaction time in a time-dependent manner. They increased blood pressure and reduced production of melatonin. Lately, EMW have also been implicated in DNA strand breaks.

Dr. Agarwal explains that use of cell phones by men is associated with decrease in semen quality. Decrease in sperm count, motility, viability and normal morphology is related to duration of use of cell phones. However, he opines more studies are needed to identify mechanism involved in reduction of semen quality.

The technicalities

Human body is a sensitive electrochemical system. Oscillatory electrical processes characterised by frequency close to GSM band determine its functioning and control. Human biological electrical activities can be interfered by oscillations in radiation. Communications protocols of phones result in low frequency pulsing of carrier signal; similar to those that exist in the electrical oscillations of the human body. Radiation changes sleep rhythm, affect’s body's cancer-fighting capacity by harming immune system, and changes nature of electrical and chemical signals communicating between cells. These changes lead to functional changes in nervous system. It causes red blood cells to leak hemoglobin, leading to heart disease and kidney stones.

Human brains and bodies depend on tiny electrical impulses to activate complex life-processes, including ability to read, recall and respond. Like antennas, human anatomies tune into spurious RF signals. The brain has peak absorption in cell phone UHF bands. RF exposure increases production of Histamine, which triggers bronchial spasms, reducing effectiveness of anti-asthmatic drugs. It causes dielectric heating, wherein living tissue, a dielectric material, is heated by rotations of induced polar molecules. The brain's blood disposes of excess heat by increasing blood flow. However, the cornea of the eye does not have such temperature regulation mechanism.

Changes in human cells affect the brain. Some parts of head are more sensitive to damage due to increases in temperature, particularly in anatomical structures with poor vasculature, such as nerve fibers. Continuous use of mobile phone leads to probability of brain tumor. Molecules of blood cells are made to align in the same direction, resulting in increase in forces between bloods cells. Stronger attractive forces between cells might make them clump together or cause blood cells to contract.

Low intensity exposure opens up blood/brain barrier resulting in release of dangerous chemicals into the brain, enabling poisons to penetrate the brain. This causes confusion, short-term memory loss, disrupt part of brain, which controls memory and learning, and affects nervous system. Frequent or prolonged calls cause headaches, fatigue, lethargy, nausea, dizziness, depression, arteriosclerosis, and cardiac problems.

Rate at which radiation is absorbed by the human body is measured by specific absorption rate (SAR). Regulating agencies has set its maximum levels for handsets. Radiations depend on its design, antenna, how it is held and used. Institute of Electrical and Electronics Engineers Committee on Man and Radiation, national and international organisations have established guidelines for exposure to RF energy.

Key factors responsible for radiation hazards include frequency, exposure duration, cellular traffic, transmission quality, antenna extension amplitude, modulation, handset size, power output and distance from the body. Cell phones can affect the operation of heart pacemakers or defibrillators, and hearing aids. They should be used on the other side of the body away from the implanted pacemaker. To reduce risk, radiation absorbed by body should be reduced. Protective devices are being launched to contain and minimise radiation hazards.

The aftermath

Cell phones are an inevitable part of our lifestyle and work environment. At the same time, it is not prudent to wish away radiation hazards posed by mobile handsets. Manufacturers of mobile phones and mobile service providers need to ensure that level of exposure to radiation is reduced by careful design of phones and base stations, keeping RF emissions below stipulated safe levels. More work needs to be done in this field.