As mobile phone penetrations grew past fixed landline penetration levels in 1998 in Finland and from 1999 in Sweden, Denmark and Norway, the Scandinavian health authorities have run continuous long term studies of effects of mobile phone radiation effects to humans, and in particular children.
Studies from the Institute of Cancer Research, National Cancer Institute and researchers at the Danish Institute of Cancer Epidemiology in Copenhagen for example showed no link between mobile phone use and cancer.The Danish study only covered analog mobile phone usage up through 1995, and subjects who started mobile phone usage after 1995 were counted as non-users in the study.
A study by the International Agency for Research on Cancer of 4,500 users found a borderline statistically significant link between tumor frequency on the same side of the head as the mobile phone was used on and mobile phone usage.
A 2007 study by Prof. Bengt Arnetz and colleagues of Wayne State University and Uppsala University, and Foundation IT’IS, USA, and Karolinska Institutet, Sweden, funded by the Mobile Manufacturers Forum and published in "Progress In Electromagnetics Research Symposium (PIERS) Online" reported higher incidence of headache and also disturbance of normal sleep patterns following mobile phone use.
Early in 2008, Michele Froment-Vedrine the President of AFSSET (an independent but state-funded French health watchdog), advised that parents should not give small children mobile phones. Study of the University of Segeda, Hungary showed that mobile phones carried in pockets of pants and/or worn on belts could result in loss of quantity and quality of active sperm cells by men. This fact may not be true, especially in wealthier countries such as Australia, the UK, and the US.
REVIEW OF WORK DONE
- During the 1930s the effects of low frequency electromagnetic waves on biological materials were studied in depth by physicists, engineers and biologists.
- Studies of the effects of microwaves on bacteria, viruses and DNA were performed in the 1960s and included research on heating, biocidal effects, dielectric dispersion, mutagenic effects and induced sonic resonance.
- Most biologists in turn claimed there was no evidence of a microwave effect and that the biocidal effects of microwaves were either due entirely to heating or were indistinguishable from external heating (Goldblith 1967, Lechowich 1969, Vela 1978, Jeng 1987, Fujikawa 1991, Welt 1994).
A lot of research work related to biological application of microwave is going on India & abroad. A brief summary is as follows:
- The electromagnetic energy deposition inside a 3-layer cylindrical human body model caused by loop or aperture applicators is considered analytically by P.G. Cottis, G.E. Chatzarakis and N.K. Uzunoglu (1990). Then the response to the radiators under examination is found. Numerical results are presented for several radiator dimensions and locations. A new applicator with enhanced penetration depth is proposed.
- Niels Kuster and Quirino Balzano (Feb. 1992) have been studied the energy absorption mechanism in the close near field of dipole antenna is by numerical simulations. All numerical model of the plane phantom is additionally checked by accurate as possible experimental measurements. For the plane phantom, the interaction mechanism can be well described by H-field induced surface currents. The special peak specific absorption rate (SAR) can be approximated within 3 dB by a formula based on the incident H-field or antenna current and on the conductivity and permittivity of the tissue.
- Z. C. Alex, J. Behari and Z.H. Zaidi (1994) summarized the different techniques used for the measurement of dielectric permittivity and conductivity of high loss samples in the microwave range with emphasis on biological tissues. They also measured the dielectric permittivity of Goat Liver (in vitro) in frequency range 0.4-1.2 GHz by using coaxial cable method. They calculated the relaxation frequency and spread of relaxation, solid content and protein content of the liver tissues were also calculated. My results correlate well with these available results.
- M. A. Salam, H. M. Abdallah (1995) proposed to determining the distribution of fields, induced charges and currents on a human body standing in the high electric fields produced by high volatage overhead transmission line. This method of analysis is based on the charge simulation technique. This will serve to explain the biological studies of possible long-term exposure effects to electric fields.
- Rodeny G. Vaughan and Matthew D. Devine (1995) have investigated power relations in biological tissues at microwave frequencies. They assumed human head as a 2-D dielectric slab, close to the handheld antenna and calculated the reflection coefficient, transmission coefficient and absorption loss from human head.
- Numerical results and measurements have been studied by Dina Simunic, Paul Wach, Werner Renhart and Rudolf Stollberger (1996) on spatial distribution of high frequency EM energy in human head during MRI.
- Robert F. Cleveland, Jr. and T. Whit Athey , they measured the SAR in models of the human head exposed to handheld portable radios transmitting at frequencies in the 800 MHz band. An isotropic implantable electric field probe was used to measure internal fields induced in the head models and SAR was obtained by calculation. As well as determining representative values and distributions for SAR s under various conditions. It was shown that antenna type and orientation with respect to the head are important factors affecting energy absorption.
- The interaction of microwave with biological systems in terms of heating of tissues discussed by J. Behari and G.P. Srivastava (1997) which in turn lead to changes in chemical reaction rates and current flows, the under of which demands a basic knowledge of mechanism of microwave biointeraction. A practical advantage of these lies in using this method for selective heating of tissues as in the case of cancer. Modeling of heating by using interstitial implants and interstitial antenna is discussed. Design of antennas for specific heating profile is also presented.
- Herrmann DM, Hossmann K-A (1997), they obtain about the neurological effects of microwave exposure related to mobile communication, J Neurol Sci 52: 1-14. Repacholi MH (1998) has describes about low level exposure to radiofrequency electromagnetic fields: health effects and research needs.
- Ji Chen, Zhaomei Feng and Jian-Ming J Lin (May 1998), they studied about the finite difference time domain (FDTD) method combined with the method of moments to compute the EM field of shielded radio frequency coils loaded with an anatomically accurate model of human head for high frequency magnetic resonance imaging (MRI) applications. This combined method is able to predict both the SAR and the magnetic field (known as B1 field) excited by the RF coils. Results for SAR and B1 field distribution, excited by shielded and endcapped birdcage coils, are calculated at 64,128,171 and 256 MHz. The result shows that the value of SAR increases when the frequency of the B1 field increases and the B1 field exhibits a strong inhomogenety at high frequencies.
- Transverse electromagnetic (TEM) cells used for exposing biological culture specimens to electromagnetic fields and observed possible anomalous effects by Milica Popovic, Susan C. hagness and Allen Taflov (1998). Several different cases were studied in which the number of culture dishes, the depth of the culture liquid, and the orientation of the culture dishes was varied. Further the effect of the culture dish glass bottom thickness and the meniscus of the liquid medium were examined. The FDTD results shows that there is a significant non-uniform field and specific absorption rate (SAR) distribution within the culture medium for each case examined. Hence biological dose response experiments using the TEM cell should account for the possibility of the strong localized SAR peaking in the culture media to provide useful data n setting exposure standards for wireless communications.
- G. Schmid, G. neubauer and P. R. Mazal (2000), they studied the dielectric properties of the human brain measured less than 10 hours post mortem. After animal experiments gave a clear indication that the electric conductivity of brain tissue in the frequency range 800 to 2,450 MHz decreases after death, a measurement series on 20 human brains in the time period between 3 to 10 hours post mortem was performed. Analysis of the measurement obtained on fresh tissue yielded a mean value of grey matter conductivity which is slightly higher than values given in literature today.
- The interactions of electromagnetic field with the living cells has been considered by J. Behari (1999) as stochastic resonance co-operative effects, non-equilibrium thermodynamic process and non-linear interactions. The living cells derive the energy from noise and pumps it into the modes of excitation at the driving frequency of an electromagnetic wave which give sufficient amplification of the signal and increase the signal to noise ratio. The non-linear mechanism plays their main role in the process of the transmembrane coupling of the signal to the cytoplasm. The criteria for safe exposure limits of electromagnetic field to human have been also discussed.
- Blettner M., berg G. (2000) describes about harmfullness of mobile phones. British medical association (2001) also describes about health effect of mobile phones.
- A cavity perturbation technique was employed by S. Biju Kumar, K.T. Mathew, V. Raveendranathan and P. Augustine (2001) to determine the dielectric permittivity these materials. Rectangular cavity resonators were used to measure the complex permittivity of human bile, bile stones, gastric juice and saliva. The measurements were carried out in the S and J band. It is observed that normal and infected bile has different dielectric constant and loss tangent. Dielectric constant of infected bile and gastric juice varies from patient to patient. Detection and extraction of bile stone with possible method of treatment is also discussed.
- S. K. Srivastava, B. R. Vishwakarma and R. K. Saxena (2001) presented transmission line model for loss evaluation in sand and dust storm, to examine the propagation characteristics of mm waves in sand and dust storm. The storm is considered to have main constituents i. e. sand, silt and clay, Reflection coefficient, transmission coefficient and absorption loss calculated using impedance component as a function of frequency and visibility. The length of the link containing transmission line section of sand, silt and clay of equal lengths are placed in parallel. The propagation parameter is found to depend both on frequency and visibility. It has been found that for sparsely distributed particles the reflection coefficient is reduced by several orders of magnitude as compared to the case of zero visibility.
- Eleanor R. Adair and Ronald C. Petersen (2002), they have reviewed key developments in experimental and theoretical dosimetry, as well as confirmed biological effects that have formed the basis of ever more sophisticated human exposure standards generated through the IEEE consensus process, also suggests some potential benefits to mankind of systems based on the thermogenic character of RF/MW energy absorption.