Pathophysiology 19 (2012) 43–47
Mobile phone radiation interferes laboratory immunoenzymometric assays: Example chorionic gonadotropin assays Daryoush Shahbazi-Gahrouei a , Seyed Mohammad Javad Mortazavi b , Hamid Nasri c , Azar Baradaran d , Milad Baradaran-Ghahfarokhi a,∗ , Hamid Reza Baradaran-Ghahfarokhi e a
Department of Medical Physics and Medical Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran b The Center for Research in Radiological Sciences, Shiraz University of Medical Sciences, Shiraz, Iran c Nephrology Department, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran d Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran e Baradaran Pathology Laboratory, Isfahan, Iran Received 20 September 2011; received in revised form 29 September 2011; accepted 15 January 2012
Abstract The radiofrequency radiation is of concern in hospital laboratories as the microwaves have many health effects even on immune functions. The aim of this study was, however, to evaluate the effects of cell phone radiation on chorionic gonadotropin immunoassays of human serum. Two cell phones with 0.69 and 1.09 W/kg (head SAR) emitting 900 MHz radiation were used. Sixty wells with five human serum concentrations (0, 10, 100, 250, 500 mIU/mL) were used in three batches. The well heads in each batch were exposed to 900 MHz emitted from these phones, and the 0.69, 1.09 W/kg exposed batches were compared with the unexposed controls. Radiation exposure from mobile phones altered the measured serum levels especially in the wells with 100, 250, 500 mIU/mL hormone concentrations. Exposure at 1.09 W/kg SAR caused a significant loss compared to 0.69 W/kg SAR exposure. In conclusion, the microwave exposures may require attention in laboratories using immunoassays. © 2012 Elsevier Ireland Ltd. All rights reserved. Keywords: Radiofrequency radiation; Mobile phones; Human chorionic gonadotropin; Immunoassay
1. Introduction The artificial sources of radio frequency radiation have risen tremendously even in laboratories because of the ongoing needs on telecommunications, cell phones and their base stations. Irradiation may have health effects on almost everyone in the world, even those who do not have such phone [1]. The International Electro Magnetic Field (EMF) Project by World Health Organization (WHO) was started in 1996 to assess health and environmental effects of exposure to EMF in the frequency range from 0 to 300 Giga Hertz (GHz) ∗ Corresponding author at: Medical Physics and Medical Engineering Department, Isfahan University of Medical Sciences (IUMS), Isfahan 8174673461, Iran. Tel.: +98 311 7922432; fax: +98 311 6688597; mobile: +98 913 3155377. E-mail addresses: milad
[email protected],
[email protected] (M. Baradaran-Ghahfarokhi).
0928-4680/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pathophys.2012.01.002
[2–4]. The mobile phone technology uses 880 and 1800 MHz [5]. Whether Micro Waves (MW) of these instruments could cause reproductive or developmental effects is of concern [4,6–8]. As a consequence, there is a lot of interest about the possible effects of the radiation emitted from the cell phones [9]. Many “in vitro” or “in vivo” tests assess biological effects induced by cell phones radiation [10]. The emitted MW have been shown to have effects upon the mammalian brain, alterations of cognitive functions [11,12], gene expression alterations in cortex and hippocampus [13], and also impact upon the brain activity [14]. In addition, recent studies have shown that long-term exposure decreases thyroid stimulating hormone (TSH) and triiodothronine–thyroxin (T3–T4) levels [15,16]. Moreover, Forgacs et al. found that the GSM-like microwave exposures induce significant alterations in some hematological and endocrine parameters of male mice within the physiological range [17].
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Human chorionic gonadotropin (hCG) is a glycoprotein with approximately 30% carbohydrate and 9% of sialic acid. It is secreted during pregnancy by syncytiotrophoblast cells of the placenta. Serum hCG appears early during pregnancy, and its concentrations increase gradually by reaching a peak at the end of the first trimester, after which it progressively decreases until delivery. Chorionic gonadotropin tests are important tools for the pregnancy monitoring, especially during the first trimester. In fact, during this period it is important to perform serial determinations to find out if there is a threatened abortion. According to our best knowledge, no study on the effects of cell phone radiation on the “in vitro” immunoassays of chorionic gonadotropin in human serum has been published. The aim of this study was to investigate whether the hCG hormone levels in assays could be interfered by the exposure to the 900 MHz GSM cell phones in laboratory.
2. Materials and methods Human chorionic gonadotropin level can easily be tested in laboratory using a spectrophotometer. Thus, it provides a suitable model system to study the influence of RF emission on chorionic gonadotropin assays. This study was performed based on an immunoenzymometric assay (IEMA). Two cell phones with 0.69 (Nokia, Model 1100, Finland) and 1.09 (Nokia, Model 1202, India) Watt per kilogram (W/kg) of the tissue locally in the head Specific Absorption Rate (SAR), which produce 900 MHz RF radiation, were used to represent exposure of global systems for mobile communications (GSM). Sixty wells with five human serum concentrations of 0, 10, 100, 250, 500 milli International Unit (mIU/mL) were placed in three batches. The well heads in each batch at 3 cm distance were exposed to 900 MHz MW exposure emitted from the phones during assay cycle for 20 min (Fig. 1). The first (I) and second (II) batches were exposed to 1.09 and 0.69 W/kg phone respectively. Phones were on the speech mode during expose. For the batch controls, no radiation was applied to the wells and they completed their assay cycle in the well during the study period. For the assay two different anti hCG monoclonal antibodies were used, one adsorbed on the wells and the other conjugated to horseradish peroxidase (HRPO). During the first incubation, the hCG in calibrators and samples was bound to both monoclonals at once, by forming aspiration and washing. The residual enzyme activity in the wells, which was directly proportional to the hCG concentrations in calibrators and samples, were measured by adding a chromogen solution (tetramethylbenzidine, TMB) in a substrate-buffer to the wells. Spectrophotometer (Hospitex Diagnostics, Florence, Italy) was used for the colorimetric reading at 405 and 450 nm wavelengths. All experiments were performed comparing 0.69 and 1.09 W/kg exposed batches with the unexposed control batch.
Fig. 1. Well heads were exposed to radiation emitted from the speech mode mobile phones.
To avoid the variability inherent to the assay used, all tests were performed for three independent experiments. Mean values and standard deviations were calculated, and statistical significance of the differences between exposed samples and controls was evaluated. A computer program (SPSS version 16.0, Chicago, IL, USA) was used for statistical analysis. Data were analyzed by Mann–Whitney U-test. All hypotheses tested using a criterion level of P = 0.05.
3. Results Table 1, shows the final average of hCG with different levels in batches I, II and control at 405 and 450 nm reading. The final scores for the higher levels of the hCG (>100 mIU/mL) in the exposed batches I and II, were statistically significant relative to the control batch (P = 0.021) (Table 2). In other words, the results showed that, 900 MHz radiation exposure from mobile phones altered the final hCG hormone measured levels in the tests specially in the wells with 100, 250, 500 mIU/mL concentrations. Exposure at 1.09 W/kg gave significant loss to a pronounced chorionic gonadotropin compared to 0.69 W/kg exposure (Fig. 2).
4. Discussion The present work provides evidence that GSM exposure results in reduction of hCG level during the immunoassay in laboratory. This is our knowledge first this kind of report published. The results also showed that the higher SAR irradiation value caused more powerful effects than the lower one. The reason could be due to a rapid diffusion in high electromagnetic irradiation and field caused by mobile phones. The
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Table 1 Final average of chorionic gonadotropin in the 405 and 450 nm reading in the assays. Batch
Control Ib II a b
Mean ± SD 0
10a
100
250
500
0.025 ± 0.017 0.026 ± 0.017 0.025 ± 0.017
0.195 ± 0.020 0.166 ± 0.018 0.171 ± 0.019
0.695 ± 0.017 0.636 ± 0.019 0.684 ± 0.022
1.279 ± 0.023 1.222 ± 0.021 1.250 ± 0.019
1.418 ± 0.024 1.356 ± 0.019 1.368 ± 0.019
Concentration (mIU/mL). 1.09 W/kg exposed batch.
Table 2 Comparison of different levels of hCG after exposure and the P values. P value
controla
I vs II vs control I vs II a
0 (mIU/mL)
10 (mIU/mL)
100 (mIU/mL)
250 (mIU/mL)
500 (mIU/mL)
0.353 0.549 0.617
0.191 0.248 0.564
0.021 0.468 0.021
0.021 0.083 0.149
0.021 0.021 0.386
Comparison between batch I and the control batch.
Fig. 2. A comparison of average serum hCG hormone with S.D. among control, and the exposed batches I and II.
irradiation may inactivate the immunoglobulins cause them to sediment down. Also the enzyme activity can be affected. Thus the recorded concentrations could fall down for the immunoassay. Microwaves can affect the immunoassay by a MW specific, non-thermal action, and a thermal molecular effect, or a combination of these mechanisms. It is commonly accepted that MW emitted by mobile phones is at a non-thermal power density level. Lotz and Podgorski have reported that whole-body exposure with 4 W/kg SAR results in about 1 ◦ C rise in body temperature [18]. In our tests the SAR values reported by the phone producer we considerably smaller. Most recent studies of human subjects, including adults, children and adolescents, have focused on the possible effects of essentially non-thermal exposures to mobile phones [1]. A number of non-thermal interaction mechanisms have been proposed. It is, however, known that the effects caused by radiation are positively correlated with the exposure time [19]. One remarkable observation in this study was that exposure at 0.69 W/kg gave little loss to the pronounced chorionic gonadotropin assays compared to 1.09 W/kg exposure, where significant effects were seen. Perhaps, the trends seen for exposure level of 0.69 W/kg would have reached statistical significance if exposure times had been longer. Today’s investigations on immune function, human serum and living cells effects of RF exposure have received more importance in public health. Nittby et al. investigated that albumin extravasation was enhanced in the rats which were exposed to mobile phones at 12 mW/kg SAR [20]. Blank and Goodman observed that specific DNA sequences on the promoter of the HSP70 stress gene were responsive to EMF. Also they studied that low energy EMF interacts with DNA and induces the stress response, while increasing EMF energy in the RF range can lead to breaks in DNA strands [21]. de Seze et al. showed a 21% decrease of in male volunteers
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chronically exposed to GSM cell phone fields 2 h/day, 5 days/week for 1 month [22]. Zagorskaia and Rodina, found lowered concentrations of thyroid hormones during 2 months after a single exposure of rats to 20 mT extremely low frequency EMF [23]. However, Gurisik et al. found no significant difference between sham-exposed and RF-exposed cells in any of the assays or conditions examined [24]. Lee et al. reported that 1763 MHz RF radiation alone did not elicit any stress response [25]. Lantow et al. demonstrated that RF-EMF exposure of human monocytes and lymphocytes, using different RF signals and exposure times, did not have any activating capacity to induce hsp70 expression [26]. Our findings showed that EMF exposure causes profound changes in the measured hCG levels in immunoassays in laboratory. The results here were obtained by using commercial mobile phones to reproduce the reality of the human exposition and laboratory situation. In these kinds of studies on the use of commercial phones as source of RF, the variability of the RF and intensity might be considered a problem. However, commercial phones and their base stations are indeed the most common RF sources in the human exposition in everyday life also in laboratories. In conclusion, the increasing number of mobile phones, their base stations and other wireless systems as well as electromagnetic irradiation emitted from computers and other laboratory devices can physically interfere each others can also cause errors in immunoassays in laboratories. Of course the effects of cell phones on the laboratory personnel must also be kept in mind.
Conflict of interest None.
Acknowledgment The authors wish to thank pathology Specialist Dr. Sh. Baradaran-Ghahfarokhi from the Pathology laboratory, Ferdousi Street, Isfahan, Iran for her critical technical support and advice.
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