Absence of nonlinear responses in cells and tissues exposed to RF energy at mobile phone frequencies using a doubly resonant cavity
Guidelines for exposure to radiofrequency fields are based largely on thermal effects of these fields. However, controversy remains over the possibility of adverse health effects from exposure to low level fields such as those associated with the use of mobile phones. A plausible mechanism considers the demodulation of amplitude modulated RF fields by biological systems: if this were to operate, they would be exposed to low frequency fields similar to those of biological processes, and therefore with the potential for biological activity.
This study performed the experiment originally proposed by Balzano  to test whether biological cells exhibit the nonlinear responses necessary for demodulation. This would be indicated by the generation of a second-harmonic signal upon exposure of the sample to a pure fundamental signal at around 883 MHz. The experiment used a highly sensitive system employing a doubly-resonant cavity. Storage of the high-frequency energy in the highly-resonant cavity with very low noise amplification and the avoidance of any electrode contact with the samples allowed the experiments to approach the ultimate limits of physical sensitivity.
Using a wide range of biological materials, the study was not able to demonstrate non-linear conversion of RF energy by biological materials. The results do not support the hypothesis that living cells possess the non-linear properties necessary to rectify or demodulate RF energy. Therefore biological systems do not appear to act as effective radio receivers, at frequencies above a few hundred MHz.
Biophysics | Cells | Computer Sciences | Systems and Communications
Kowalczuk, C., Yarwood , G., Blackwell , R., Priestner, M., Sienkiewicz , Z., Bouffler, S., Ahmed , I., Abd-Alhameed , R., Excell, P., Hodzic , V., Davis ,C., Gammon , R. Balzano, Q. (2010) ‘ Absence of nonlinear responses in cells and tissues exposed to RF energy at mobile phone frequencies using a doubly resonant cavity’. Bioelectromagnetics Online (In advance of print)
Digital Commons Citation
Kowalczuk, Christine; Yarwood, Gemma; Blackwell, Roger; Priestner, Marisa; Sienkiewicz, Zenon; Bouffler, Simon; Ahmed, Iftekhar; Abd-Alhameed, Raed; Excell, Peter S.; Hodzic, Vildana; Davis, Christopher; Gammon, Robert; and Balzano, Quirino, "Absence of nonlinear responses in cells and tissues exposed to RF energy at mobile phone frequencies using a doubly resonant cavity" (2010). Computing. Paper 24.