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11/05/2009 - April 2009 - Science Update
The following is a quick summary of another fifteen papers that have come out over the last couple of months related to effects of electromagnetic radiation.
Bas O et al
, (February 2009) 900 MHz electromagnetic field exposure affects qualitative and quantitative features of hippocampal pyramidal cells in the adult female rat
, Brain Res. 2009 Feb 20. [Epub ahead of print] [View Author's abstract conclusions
Orhan Bas and colleagues from the Rize University School of Medicine in Turkey have published a paper in Brain Research assessing neuronal damage in rat brains from exposure to 900 MHz GSM simulated radiation. The researchers used 18 rats, in 3 groups of six (control group, sham exposed group, and GSM exposed group), and exposed them to 1 hour a day of 900 MHz radiation for 28 days to typical mobile phone exposure levels (approximately 2 W/kg locally in the head, 0.016 W/kg whole body exposure). Their findings were a statistically significant decrease in brain neurons in the hippocampus of the GSM exposed rats, and recommended that their results "may encourage researchers to evaluate the chronic effects of 900 MHz EMF on teenagers' brains".
Rodney Croft (Australian Centre for Radiofrequency Bioeffects Research) and associates have published a review of papers studying the affects of mobile phone radiation and its association with brain tumours. Concluding that the only significant results are especially prone to recall bias, they state that "research is not consistent and on balance does not provide evidence of an association". This is in strong contrast with the views of Powerwatch, especially when assessing Hardell's work on top of the INTERPHONE group results, and is also in contrast to a number of the Interphone researchers themselves.
Designed to look into the contrasting scientific opinion on the effects of mobile phone originating EMF on cellular tissues, a team from Pakistand led by Nusrat Zareen investigated the effects of exposing fertilized chicken eggs to a ringing mobile phone at different stages of development. Their findings were a statistically significant difference between experimental and control embryos with regards to retinal growth and pigmentation of the epithelium, concluding that EMF emitted by a mobile phone cause derangement of chicken embryo retinal differentiation.
Another paper from Turkey looking at in vivo effects of mobile phone based RF on rats, this time from the Yuzuncu Yil University in Van, has published a paper showing that the ovaries of females by the radiation. They used 39 rats in the control group and 43 rats in the study group, which they exposed to 15 minutes of a mobile phone in talk mode (and 11 hours 45 minutes in standby mode) for each 12 hour cycle over 21 days. Their findings were statistically significant, leading them to "suggest that intrauterine exposure has toxic effects on ovaries", and conclude that that "the microwaves of mobile phones might decrease the number of follicles in rats by several known and, no doubt, countless unknown mechanisms".
Michael Kundi of the Medical University of Vienna (and co-author of the BioInitiative report) has published a paper assessing the current situation on the effects of mobile phone base stations on wellbeing and health. Highlighting the explicit discouragement of further work into this area by the WHO International EMF Project and COST 281, he highlights the possibility that this advice is unreasonable and that investigation of these issues is urgent in the light of the sparse existing evidence which demonstrates the possibility of a significant health risk. He concludes that "The difficulties of investigating long-term effects of base station exposure have been exaggerated, considering that base station and handset exposure have almost nothing in common both needs to be studied independently. It cannot be accepted that studying base stations is postponed until there is firm evidence for mobile phones."
Budak GG et al
, (March 2009) Effects of intrauterine and extrauterine exposure to GSM-like radiofrequency on distortion product otoacoustic emissions in infant male rabbits
, Int J Pediatr Otorhinolaryngol. 2009 Mar;73(3):391-9. Epub 2008 Dec 23 [View Author's abstract conclusions
This is another Turkish in vivo paper, this one by Gurer Budak of the Nanomedicine Research Laboratory in Ankara, measured the effects of simulated GSM 1800 RF exposure on the hearing function of juvenile rabbits. They separated the rabbits into 4 groups: control, exposed for the first 14 days of life, exposed for the third week of gestation, and exposed both in gestation and for the 14 days after the first month of life. Their findings were that, for those rabbits in both groups exposed for the 14 days after the first month of life, a significant increase in hearing impairment when compared to the control group and the group exposed only before birth. They concluded that "Harmful effects of RF are mainly observed as a decrease in DPOAE amplitudes at 4.0-6.0 kHz during extrauterine exposure in infancy. During the intrauterine period, the water content of the middle and inner ear and amnion fluid may play a protective role. Therefore, children must be protected from RF exposure. The use of mobile phones at short distances from the ear of the infants should be avoided because of the lower thickness of the anatomical structure in infancy."
A number of researchers from the University of Tehran in Iran, investigated the effect of 900 MHz mobile telephony radiation (specifically 910 and 940 MHz) on the structure and function of haemoglobin. They found that their results indicated that mobile phone EMFs altered oxygen affinity and tertiary structure of HbA. Furthermore, the decrease of oxygen affinity of HbA corresponded to the EMFs intensity and time of exposure.
Dahmen N et al
, (March 2009) Blood laboratory findings in patients suffering from self-perceived electromagnetic hypersensitivity (EHS)
, Bioelectromagnetics. 2009 Mar 3;30(4):299-306. [Epub ahead of print]Click here to read [View Author's abstract conclusions
Norbet Dahmen Bas and colleagues from the university of Mainz in Germany have published a paper in Bioelectromagnetics assessing self-proclaimed EHS patients for signs of other somatic health problems. Using a number of standard laboratory tests for other ailments, they found that signs of thyroid dysfunction, liver dysfunction and chronic inflammatory processes in small but remarkable fractions of EHS sufferers as potential sources of symptoms that merit further investigation in future studies. These results were found to be statistically significant, and the authors conclude that "Clinically it is recommended to check for signs of treatable somatic conditions when caring for individuals suffering from self-proclaimed EHS." This could be potentially be an objective marker for those with EHS that may help alleviate related symptoms.
Martin Blank (ex-president of the Bioelectromagnetics Society) and Reba Goodman have published a paper in pathophysiology reviewing the literature on both ELF and RF EMF on heat shock proteins and cell stress, including describing what is currently understood about the relevant pathways. Observing the apparent lack of relevance of the energy difference between the frequencies, they conclude that "in order to protect living cells, EMF safety limits must be changed from the current thermal standard, based on energy, to one based on biological responses that occur long before the threshold for thermal changes."
Novikov VV et al
, (March 2009) Effect of weak combined static and extremely low-frequency alternating magnetic fields on tumor growth in mice inoculated with the Ehrlich ascites carcinoma
, Bioelectromagnetics. 2009 Mar 6. [Epub ahead of print] [View Author's abstract conclusions
Cellular Biophysicists, led by Vadim Novikov, have identified strong tumour-inhibitive properties of MF (1, 4.4 and 16.5 Hz AC magnetic fields at around 150 to 300 nanotesla combined with 42 microtesla static magnetic fields) in mice. They found that in the mice transplanted with Ehrlich ascites carcinoma tissue, the tumourous tissue had virtually disappeared in those exposed to the magnetic fields, whereas in the unexposed mice the tumours had spread to most internal organs at the point of examination. In the control group (without transplanted carcinoma tissue) the magnetic fields did not appear to have any effect on the organs of the mice.
The latest paper published by Lennart Hardell (again with Carlberg and Mild) on wireless phones and brain tumours was also published in March in the Pathophysiology journal. Performing a meta-analysis on a combination of their work and the INTERPHONE work, they found no increase overall for Gliomas (OR = 1.0), but an increase to OR = 1.3 for greater than ten years of usage (CI 1.1 - 1.6), and an OR for 1.9 for ipsilateral exposure (tumour on the same side of the head as phone usage). They found almost identical result for acoustic neuromas (although ipsilateral OR for greater than 10 years use was only 1.6), but found no consistent pattern of increased risk for meningiomas. Their conclusions were as follows: "In summary our review yielded a consistent pattern of an increased risk for glioma and acoustic neuroma after >10 year mobile phone use. We conclude that current standard for exposure to microwaves during mobile phone use is not safe for long-term exposure and needs to be revised."
Finnie JW et al
, (April 2009) Heat shock protein induction in fetal mouse brain as a measure of stress after whole of gestation exposure to mobile telephony radiofrequency fields
, Pathology. 2009 Apr;41(3):276-9 [View Author's abstract conclusions
John Finney of the Hanson Institute Centre for Neurological Diseases in Australia has just released a paper through the journal Pathology failing to find any evidence of heat shock proteins in the offspring of pregnant mice exposed to 4 W/kg "pre-designed" 900 MHz RF exposure system for 60 minutes per day for the first 19 days of gestation. It is worth noting that there is no reference to whether or not the pre-designed exposure system is a simulation of a form of modern "real life" telephony signals, nor is the fact that the exposure was far field particularly relevant to near field mobile phone exposure. Nevertheless, the authors conclude that "whole of gestation exposure of fetal mouse brains to mobile phone radiofrequency fields did not produce any stress response using HSPs as an immunohistochemical marker."
, (March 2009) Genetic damage in mammalian somatic cells exposed to extremely low frequency electro-magnetic fields: A meta-analysis of data from 87 publications (1990-2007)
, Int J Radiat Biol. 2009 Mar;85(3):196-213 [View Author's abstract conclusions
Vijayalaxmi and Thomas Prihoda of the University of Texas Health Science Center have performed a meta-analysis of data in 87 publications from 1990 to 2007 for evidence of genetic damage in mammalian somatic cells exposed to ELF EMF. They found that "(1) The difference between ELF-EMF-exposed and control cells as well as the 'effect size' due to ELF-EMF exposure were biologically small (although statistically significant) with very few exceptions. (2) At certain ELF-EMF exposure conditions there was a statistically significant increase in genetic damage assessed from some end-points. (3) The mean indices for chromosomal aberrations and micronuclei end-points in ELF-EMF-exposed and control cells were within the spontaneous levels reported in historical database. (4) Considerable evidence for publication bias was found in the meta-analysis."
Burda H et al
, (April 2009) Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants
, Proc Natl Acad Sci U S A. 2009 Apr 7;106(14):5708-13. Epub 2009 Mar 19 [View Author's abstract conclusions
Following up on earlier work with roe deer, researcher Hynek Burda and colleagues from the University of Duisberg-Essen in Germany have found that the magnetic fields generated by high voltage overhead powerlines can disrupt the natural north-south alignment of cows. They conclude that "These findings constitute evidence for magnetic sensation in large mammals as well as evidence of an overt behavioral reaction to weak ELFMFs in vertebrates. The demonstrated reaction to weak ELFMFs implies effects at the cellular and molecular levels."
An American team of researchers from Pittsburgh assessed 11 studies to date that analysed the possible association between mobile phone use and the development of acoustic neuromas. Out of the 10 case-control studies (and 1 cohort study, the 2006 Schuz paper we covered in detail at the time), they found that the odds ratios varied from 0.5 (two-fold protective effect) to 4.2 (over four-fold increase in risk). Acknowledging that the latency of acoustic neuromas made evaluation of the risks challenging, they still found that their meta-analysis "found that subjects who used cell phones for at least 10 years had a 2.4-fold greater risk of developing ipsilateral acoustic neuromas".