Biological effects of low power microwave radiation on proteins and cells: modelling and experimental evaluation

Rapid growth in telecommunication and related technologies has resulted in increased exposure of human population to low power non-ionising Electromagnetic Radiation (EMR). This research is focussed on studying biological effects of low power EMR at the molecular and cellular levels. Radiofrequency/Microwave (RF/MW) radiation has been integrated into modern telecommunication systems, health (medical devices) and even food technology. However, the increasing rate of exposure to RF/MW radiation (especially exposures from mobile phones) has raised a health concern and stimulated much research into biological and health effects of MWs and the mechanisms of interaction between MW radiation and living matter. The primary objectives of this project are: (i) to improve our understanding of the impact of low power MWs (1.8 GHz - 2.6 GHz) emitted by handheld mobile communication devices on ion channel proteins, isolated enzymes and yeast cells; and (ii) determine the safe thresholds of induced biological effects. This project has two arms (computational and experimental) and is undertaken via the sequentially linked four sub-studies: (i) Molecular simulation of Conotoxin protein exposed to low strengths static and oscillating electric fields; (ii) in-vitro evaluation of MW radiation (frequencies 2.1 GHz, 2.3 GHz and 2.6 GHz and powers -10, 0 and 17dBm) on biological activity of L-Lactate Dehydrogenase and Catalase enzymes; (iii) in-vitro evaluation of changes in growth rate of yeast cells exposed to MW radiation (frequencies 1.8GHz and 2.1GHz and powers -10, 0d, and 17dBm, and (iv) in-vitro evaluation of MW radiation (frequency 1.8 GHz and powers -10, 0, 17 dBm) on bioactivity of TRP ion channel proteins (expressed in epithelial cells). The findings are summarised as follows: (i) in-silico analysis show that conformational changes in Conotoxin occur under the exposure to weak static and oscillating electric fields of particular strengths; (ii) low power MW radiation induces modulating (inhibition and promotion) effects on LDH and Catalase enzyme kinetics at the particular frequencies and powers of exposures. The results indicate the frequency- and power-dependence of the observed biological effects; (iii) low power MW radiation induces cell proliferation or inhibition on yeast cells growth depending on the exposure parameters, and (iv) effects of MW exposures at the particular powers induce n Ca2+ ion influx and affects gating function of TRP ion channel proteins. In essence, this study demonstrated that even non-thermal microwave exposures produce modulating effects at the molecular and cellular levels. The outcomes of this study will assist in understanding the bioeffects of low power MWs and their interaction with biological media. It will also assist in identifying thresholds of MW exposures affecting the selected proteins and cells, and will be useful in providing much-needed evidence on defining safe exposure limits. Further investigation of the mechanism of action of microwaves of different frequency and power combinations is proposed for future work as an extension of this project