The influence of electromagnetic radiation generated by a mobile phone on the skeletal system of rats
Sieroń-Stołtny K, Teister Ł, Cieślar G, Sieroń D, Śliwinski Z, Kucharzewski M, Sieroń A. The influence of electromagnetic radiation generated by a mobile phone on the skeletal system of rats. Biomed Res Int. 2015;2015:896019. doi: 10.1155/2015/896019. Epub 2015 Feb 1.
The study was carried out on male rats divided into two groups: experimental group subjected to 28-day cycle of exposures in electromagnetic field of 900 MHz frequency generated by mobile phone and a control, sham-exposed one.
The mobile phone-generated electromagnetic field did not influence the macrometric parameters of long bones and L4 vertebra, it altered mechanical properties of bones (stress and energy at maximum bending force, stress at fracture), it decreased the content of calcium in long bones and L4 vertebra, and it altered the concentration of osteogenesis and bone resorption markers in rats.
On the basis of obtained results, it was concluded that electromagnetic field generated by 900 MHz mobile phone does not have a direct impact on macrometric parameters of bones; however, it alters the processes of bone mineralization and the intensity of bone turnover processes and thus influences the mechanical strength of bones.
Open Access: http://bit.ly/1ApGYGk
A substantial part of the human population is exposed to electromagnetic fields generated by mobile phones. Statistics (ITU Yearbook of Statistics 2012: 38th edition; Chronological Time Series 2002–2011, edited by International Telecommunication Union; English Edition online: http://www.itu.int/ITU-D/ict/
Mobile phones emit electromagnetic radiation within the microwave frequency range (900–2450 MHz), which may pose a danger to human health due to causing thermal as well as nonthermal effects, such as genotoxicity, carcinogenicity, and sleep disorders [1–3].
Biological effects of the influence of low-frequency electromagnetic field on living organisms have been the research topic of much experimental research in recent years. It was demonstrated that electromagnetic fields accelerate the regenerative processes of many types of tissue, including the processes of building up and thickening of bones, shortening the time of postfracture bone union, and the creation of proper union in pseudoarthrosis. In vitro examinations demonstrated a stimulating effect of the low-frequency pulsed electromagnetic field on osteogenesis and intensification of the mRNA expression of the bone morphogenetic proteins (BMP-2 and BMP-μ) in rat osteoblast cultures [4–7]. So far, however, it remains debatable whether there exists influence of mobile network generated electromagnetic fields (frequencies of 900 to 2500 MHz) on living organisms. International experimental and epidemiological research which has been carried out for the last ten years has not been able to determine conclusively whether there exists the possibility of causing activity changes in cells and tissue by such fields ....
The aim of the research carried out in this paper was to assess the influence of the electromagnetic fields generated by Nokia 5110 (frequency of 900 MHz) mobile phone on rat skeletal system ...
The research was conducted on two groups of rats. (1) The control group was subjected to 28-day cycle of sham exposures. While placed in the exposure cage (Figure 1), electromagnetic field was not generated. The time of sham exposure was 22 hours per day with a 2-hour break between . (2) The experimental group was subjected to 28-day cycle of exposures to the electromagnetic field generated by a mobile phone (900 MHz frequency Nokia 5110). For this phone, the highest SAR value under the ICNIRP guidelines for use of the device (tests conducted using standard operating positions with the device transmitting at its highest certified power level in all tested frequency bands) stated by the manufacturer was 0.69 W/kg of body weight. As the SAR value depends among others on how close the phone is placed to the body, in this experimental model in which the animals were allowed to move freely inside of a cage during the exposure, the measurement of precise real value of SAR for animal moving inside exposure workstation was not possible. That is, the strength of the electromagnetic field generated by mobile phone was measured as the average density of the electromagnetic field.
... During the exposure, the phone was switched on for 15 seconds every half an hour and it was controlled by automatic electronic system using fax signal. In the programmed time intervals, the connection was established for a definite time period. The mobile phone as a final terminal had a function of an automatic receipt of connection switched on. The connection was not cancelled, as it happens in case of lack of phone call, due to a fax signal, which was active during the whole time of the connection.
The mobile phone operated in a silent mode; it means that both sound of a bell and sound in the receiver were switched off, so the animals were exposed solely to electromagnetic field generated by the mobile phone.
The total number of connections for twenty-four hours was 16. The average density of the electromagnetic field recorded in the process of establishing the connection was 85.3 μW/m2. The average density of the electromagnetic field throughout the established connection was 17.0 μW/m2.
The results obtained in this research have shown that the ratio of calcium to phosphorus in the mass of mineral substances was 2.15 in the rats from the control group, which indicated that the main mineral substance in these bones of the rats from the control group was hydroxyapatite, in which the calcium to phosphorus ratio is exactly 2.15.
In rats exposed to the electromagnetic field generated by mobile phone (Nokia 5110, 900 MHz), a decrease in this ratio (Ca/P) was observed in the bone studied. It dropped to 1.85 in tibia and 1.98 in L4 vertebra.
This data may suggest that lowering the calcium content in bones is due to its escape into blood or a remodelling of the hydroxyapatite structure under the influence of the electromagnetic field.
The latter of the aforementioned hypotheses is supported by the lack of the influence of the electromagnetic field generated by a mobile phone on the concentration of total calcium and total phosphorus in blood serum, which was established in this study.
The electromagnetic field generated by Nokia 5110 (900 MHz) mobile phone does not have a direct impact on the macrometric parameters of bones; however, it alters the processes of bone mineralization and the intensity of bone turnover processes (osteogenesis and bone resorption) and thus influences the mechanical strength of bones.