To study the non-thermal effects of millimeter waves in the frequency range from 41-43 GHz on the growth rate and the absorption spectrum of Escherichia coli. In addition, the effect of this exposure on DNA was studied by measuring plasmid transformation efficiency.
Exposure duration: continuous for 40 min.
growth rate experiment
Exposure duration: not given in the article
Exposure duration: continuous for 15 min.
|Setup||1 cm thick piece of Styrofoam placed on top of the pyramidal horn antenna in the anechoic chamber; samples positioned on top of the Styrofoam - one sample in a well in the center of the horn, the other in the adjacent well of a 12-well culture plate|
|Sham exposure||A sham exposure was conducted.|
No parameters are specified for this exposure.
|power density||12 mW/cm²||-||calculated||-||-|
The data did not show any statistically significant frequency-dependent effects on the growth of bacteria, nor any frequency-dependent effects on the DNA plasmid transformation efficiency. The only indication for resonant effects was found in the absorption spectrum of Escherichia coli. However, in control experiments and by changing the length of the waveguides in the millimeter wave system, the resonant-like absorption was found to be caused by the millimeter wave system itself.
The findings indicate that resonance effects are unlikely in this particular frequency range.