Tackling the problem of thermal versus non thermal biological effects of high frequency electromagnetic radiations

We have developed a new test based on the acquired protection of the protein "Luciferase" toward thermal stresses. This test is based on the observations that after submitting an organism to a small increase in temperature (1-2°C), proteins are protected against "in vivo" thermal inactivation at high temperature (more than 40°C). We have submitted a test organism (the moss plant Physcomitrella patens) either to a continuous 900MHz, 500 V/m (peak value) field or to a pulsed 866 V/m (peak value) field (on/off keying 20s/60s). Both fields have the same r.m.s. value of about 354 V/m. It is expected that the thermal effect of the second treatment will be negligible. Our results show that the pulsed field cannot elicit the same protection mechanism than the continuous field. This observation clearly favors a simple thermal effect of high intensity, high frequency EMF on the induction of heat shock response and will challenge many claims of a non-thermal mechanism of induction. In order to quantify more precisely the heat shock response, we have created stable transformed P. patens carrying a heat-stable reporter gene (uidA), under the control of soybean promoter for the heat shock protein hsp 17.3. We also present similar experiments conducted on other test systems developed in our laboratory. This includes the effects of high frequency EMF on the behavior of the nematode C. elegans measured by the analysis of the complexity of traces.