Conceptualization and Realization of a Vibrating Intrinsic Reverberation Chamber for Plant Exposure to Radio Frequency Electromagnetic Fields.

The increasing use of mobile communication devices and wireless data transfer leads to public concerns about potential negative impacts on the living world, resulting from the emitted radio frequency-electromagnetic fields (RF-EMF). In order to provide knowledge-based information on how RF-EMF might affect biological organisms, well-controlled studies are needed, where the actual electric field parameters are monitored over time and at the location of the tested organisms. Such controlled studies are scarce, particularly regarding the assessment of potential effects of RF-EMF on plant growth and health. Here, we report the implementation of a vibrating intrinsic reverberation chamber (VIRC) inside a walk-in plant growth chamber for controlled RF-EMF studies on plants. The designed VIRC functions as a mode-stirred reverberation chamber and allows real-time monitoring of the electric field over the entire time of plant exposure within a defined working volume where the plants are placed. We demonstrate that the electric field inside the designed VIRC is stable and statistically uniform, that is, spatially homogeneous and isotropic, over multiple exposure times, various field strengths, and when loaded with different plant species. Therefore, it is a suitable setup for controlled experiments assessing the effects of RF-EMF on plants. Using the VIRC, we show that repeated short-term exposures (30 min) of rose cuttings to RF-EMF (900 MHz, 5 V/m) do not affect shoot growth or leaf development compared to sham exposure (0 V/m). The VIRC was designed for a frequency of 900 MHz and electric field strength ranging from 0 to 40 V/m. The concept, however, can be adapted to different RF-EMF exposure requirements.