08/05/2008 - Review of Recent Papers
The following is a quick summary of another six papers that have come out recently - both radiofrequency and powerfrequency related.
Baste V et al
, (April 2008) Radiofrequency electromagnetic fields; male infertility and sex ratio of offspring
, Eur J Epidemiol. 2008 Apr 16 [Epub ahead of print] [View
This study analysed the responses from 10,497 respondents in a cross-sectional study amongst employees in the Royal Norwegian Navy regarding fertility information and self-assessed exposure to radio frequency electromagnetic radiation.
They found that infertility increased significantly along with increasing self-reported exposure to radiofrequency electromagnetic fields. Odds ratio (OR) for infertility among those who had worked closer than 10m from high-frequency aerials to a "very high" degree relative to those who reported no work near high-frequency aerials was 1.86 (1.46-2.37), adjusted for age, smoking habits, alcohol consumption and exposure to organic solvents, welding and lead. Similar adjusted OR for those exposed to a "high", "some" and "low" degree were 1.93 (1.55-2.40), 1.52 (1.25-1.84), and 1.39 (1.15-1.68), respectively.
Whilst there is an issue of recall bias, the consistent statistically significant findings lend further support to the paper at the beginning of the year finding an association between increased mobile phone usage and a decrease in male fertility (Agarwal A, Jan 2008).
Vianale G et al
, (April 2008) Extremely low frequency electromagnetic field enhances human keratinocyte cell growth and decreases proinflammatory chemokine production
, Br J Dermatol. 2008 Apr 10 [Epub ahead of print] [View
This paper looks at cellular responses to high levels of ELF radiation, finding evidence that 1mT fields (far above environmental levels) can have an effect on enhancing skin tissue repair. Whilst this is a therapuetic effect, it is yet more evidence that tissue heating and electrical shocks are not the only effects that can be found from non-ionising radiation.
Manti L et al
, (May 2008) Effects of Modulated Microwave Radiation at Cellular Telephone Frequency (1.95 GHz) on X-Ray-Induced Chromosome Aberrations in Human Lymphocytes In Vitro
, Radiat Res. 2008 May;169(5):575-83 [View
Cell exchanges between irradiated cell cultures were found to be increased after exposure to 24 hours exposure of typical mobile phone exposure levels of UMTS radiation (0.5 W/kg and 2.0 W/kg exposures). The study authors found that whilst the cell mutations were not increased, the increased cellular interactions demonstrate an influence of pulsed radio frequency electromagnetic fields on biological systems at a cellular level.
Interestingly, this supports work by Juutilainen et al on power frequency fields, where he successfully demonstrated that ELF EMFs could be used to enhance the proliferation of known environmental carcinogens (Juutilainen J, Jan 2006). These results both demonstrate that electromagnetic fields below the levels required to induce heating or electric shock are capable of interacting with biological systems at a cellular level, and are further indicators that guidance levels not taking such effects into account are in need of urgent revision.
Yao K et al
, (May 2008) Effect of superposed electromagnetic noise on DNA damage of lens epithelial cells induced by microwave radiation
, Invest Ophthalmol Vis Sci. 2008 May;49(5):2009-15 [View
This provided fascinating support for the work of Ted Litovitz, in that superimposed EMF "white noise" can suppress other effects caused by less random EMF signals. Having found that 1800 MHz pulsed RF exposure increased levels of cellular DNA damage in epithelial cells, they found that these effects were completely suppressed when the RF was superimposed with 2 milliTesla electromagnetic fields.
Cellini L et al
, (May 2008) Bacterial response to the exposure of 50 Hz electromagnetic fields
, Bioelectromagnetics. 2008 May;29(4):302-11 [View
This paper is more of a mechanistic proposal of the interaction between power frequency electromagnetic fields (again, around 0.1 - 1 milliTesla, around 3 orders of magnitude above typical environmental exposures) and cell cultures, in this case prokaryotic microorganisms. The authors comment that their findings "indicate that an exposure to 50 Hz EMF acts as a stressing factor on bacteria which can represent a suitable model to investigate acute and chronic effects related to ELF-EMF exposure". Again, this has no direct equivalence to health effects, but it is another offer of a biological mechanism that could help to explain those health effects already observed.
George DF et al
, (May 2008) Non-thermal effects in the microwave induced unfolding of proteins observed by chaperone binding
, Bioelectromagnetics. 2008 May;29(4):324-30 [View
Using microwave radiation levels sufficient to heat tissue, this study demonstrates that heating proteins by radio frequency radiation (2450 MHz used) causes more thermal stress damage than heating the proteins to the same temperature by convential means. Whilst the levels used are very high, this gives an indication that RF radiation is responsible for heat shock responses that cannot be entirely due to the heating effect alone - something already found in other non-thermal EMF research (de Pomerai DI, May 2003,Czyz J, May 2004,Perez FP, April 2008).