ID Number		1731
Study Type		In Vitro
Model		Microwave (900 and 2400 MHz, CW) exposure to human skin cells, yeast cells, plant cells and insects and analysis of growth and gene expression.
Details		Tomato plants (Lycopersicon esculentum) were exposed to 900 MHz (CW) RF using a reverberation chamber system at a field strength of 5 V/m. Plants were exposed for various times during the first 3 weeks (from seedlings to ~12 cm, 4th leaf emerging) and analyzed for gene expression using real time quantitative PCR. The authors report a rapid (5-15 minute) and transient (2-5 fold) increase in LebZIP1, a known responsive gene to various stimuli and involvement as an immediate early response gene. In subsequent studies, 3-week old tomato plants were exposed as above for 10 minutes and analyzed for stress gene expression (actin control, calmodulin-N6, lecdpk-1, pin2). The authors report exposures resulted in a 4 to 5.5 fold increase in stress response genes within 15 minutes, declining at 30 minutes, and increasing again at 60 minutes post-exposure. ATP levels also declined significantly by 30 minutes post-exposure. Authors' abstract: Roux et al. (2010): We exposed normal human epidermal keratinocytes to short duration, high frequency, and low amplitude electromagnetic fields, similar to that used by mobile phone technologies. We paid particular attention to the control of the characteristics of the electromagnetic environment generated within a mode stirred reverberation chamber (statistical homogeneity and isotropy of the field and SAR distribution). Two non-thermal exposure conditions were tested on the epidermal cells: 10-min exposure with a field amplitude of 8 V/m, and 30 min with 41 V/m. Corresponding specific absorption rates ranged from 2.6 to 73 mW/kg (continuous wave, 900 MHz carrier frequency). We collected RNA from cells subjected to these conditions and used it for a large-scale microarray screening of over 47000 human genes. Under these conditions, exposure of keratinocytes to the electromagnetic field had little effect; only 20 genes displayed significant modulation. The expression ratios were very small (close to 1.5-fold change), and none of them were shared by the two tested conditions. Furthermore, those assayed using polymerase chain reaction did not display significant expression modulation (overall mean of the exposed samples: 1.20 ± 0.18). In conclusion, the data presented here show that cultured keratinocytes are not significantly affected by EMF exposure. Authors' abstract: Vian et al. 2006 (IEEE #5202):The physiological impact of nonionizing radiation has long been considered negligible. However, here we use a carefully calibrated stimulation system that mimics the characteristics (isotropy and homogeneity) of electromagnetic fields present in the environment to measure changes in a molecular marker (mRNA encoding the stress-related bZIP transcription factor), and show that low amplitude, short duration, 900 MHz EMF evokes the accumulation of this mRNA. Accumulation is rapid (peaking 5-15 min after stimulation) and strong (3.5-fold), and is similar to that evoked by mechanical stimulations. AUTHORS' ABSTRACT: Bertrand et al. 2018 (IEEE #7009): Studies of the effects of electromagnetic waves on Saccharomyces cerevisiae emphasize the need to develop instrumented experimental systems ensuring a characterization of the exposition level to enable unambiguous assessment of their potential effects on living organisms. A bioreactor constituted with two separate compartments has been designed. The main element (75% of total volume) supporting all measurement and control systems (temperature, pH, agitation, and aeration) is placed outside the exposure room whereas the secondary element is exposed to irradiation. Measurements of the medium dielectric properties allow the determination of the electromagnetic field at any point inside the irradiated part of the reactor and are consistent with numerical simulations. In these conditions, the growth rate of Saccharomyces cerevisiae and the ethanol yield in aerobic conditions are not significantly modified when submitted to an electromagnetic field of 900 and 2400/MHz with an average exposition of 6.11/V.m1 and 3.44/V.m1 respectively.
Findings		No Effects
Status		Completed With Publication
Principal Investigator		Blaise Pascal University, Aubiere France - Alain.Vian@univ-bpclermont.fr
Funding Agency		Private/Instit.
Country		FRANCE
References		Roux, D et al. Planta, (2008) 227:883-891 Roux, D et al. , (2004) :- Roux, D et al. Bioelectromagnetics., (2011) 32:302-311 Vian, A et al. Plant Signal Behav., (2006) 1:67-70 Bertrand, E et al. Bioresource Technology., (2018) 260:264-272 Gremiaux, A et al. Journal of plant physiology., (2016) 190:44-53
Comments