Investigation of the effect of microwave irradiation (2.45 GHz) on biological systems at constant bulk temperature

In this thesis the effect of MW irradiation (2.45 GHz) at constant bulk temperature was investigated on several biological systems. Studies on enzymatic activity revealed that MW irradiation could enhance the activity of trypsin, however the enzymatic activity of α-amylase and alkaline phosphatase towards the hydrolysis of starch and 4-nitrophenyl phosphate was not affected. We found that the incorporation of a BODIPY fatty acid (4,4-difluoro-5-methyl-4-bora-3a,4a-diaza-s-indacene-3-dodecanoic acid) into the cell membrane of PC-3 (human prostate cancer) cells was facilitated by microwave treatment at constant temperature. Also, microwave treatment while non-apoptotic, significantly increased the rate of reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) by PC-3 cells. Further studies revealed that MW irradiation (10 W, SAR: 700 mW/ml) could significantly increase the uptake of an anticancer drug (doxorubicin) by PC-3 and MCF-7 (human breast cancer) cells at constant bulk temperature. Studies on bacterial growth revealed that MW irradiation could significantly decrease the growth of Escherichia coli at constant bulk temperature and the impact appeared to be transient. A 2D-gel electrophoresis-based proteomic analysis revealed that the expression of a series of proteins likely involved in metabolism was affected by the exposure to the MW irradiation. Overall, the results demonstrated in this study provided additional evidence for the “microwave-specific effects” that are capable of altering the behaviour of biological systems in a way that is quite different from conventional heating (through conduction). Appropriate interpretations of these observations have to also consider the possibility of local heating and/or micro-hotspot formation during MW irradiation. In this respect, the “microwave-specific effects” may not be interpreted either entirely or partially as non-thermal in nature

Low intensity microwave radiation as modulator of the L-lactate dehydrogenase activity

In this study, we investigated experimentally the possibility of modulating protein activity by low intensity microwaves by measuring alternations of L-Lactate Dehydrogenase enzyme (LDH) activity. The LDH enzyme solutions were irradiated by microwaves of the selected frequencies and powers using the Transverse Electro-Magnetic (TEM) cell. The kinetics of the irradiated LDH was measured by continuous monitoring of nicotine adenine dinucleotide, reduced (NADH) absorbance at 340 nm. A comparative analysis of changes in the activity of the irradiated LDH enzyme versus the non-radiated enzyme was performed for the selected frequencies and powers. It was found that LDH activity can be selectively increased only by irradiation at the particular frequencies of 500 MHz [electric field: 0.02 V/m (1.2 9 10-6 W/m2)- 2.1 V/m (1.2 9 10-2 W/m2)] and 900 MHz [electric field: 0.021-0.21 V/m (1.2 9 10-4 W/m2)]. Based on results obtained it was concluded that LDH enzyme activity can be modulated by specific frequencies of low power microwave radiation. This finding can serve to support the hypothesis that low intensity microwaves can induce non-thermal effects in bio-molecules

Mögliche gesundheitliche Auswirkungen verschiedener Frequenzbereiche elektromagnetischer Felder (HF-EMF). Endbericht zum TA-Projekt

Hochfrequente elektromagnetische Felder (HF-EMF) bilden die Grundlage aller digitalen, drahtlosen Kommunikation im gesamten öffentlichen Raum und in den privaten Haushalten. In den kommenden Jahren ist mit einer weiteren Zunahme von EMF-Quellen verschiedener Frequenzbereiche zu rechnen. Hauptgrund hierfür ist die rasant fortschreitende Digitalisierung nahezu aller Arbeits-, Lebens- und Wirtschaftsbereiche, die zugleich eng mit mobil zu nutzenden Technologien verbunden ist. Vor diesem Hintergrund stellt der vorliegende Bericht den aktuellen Wissensstand zu möglichen gesundheitlichen Risiken elektromagnetischer Felder – insbesondere des Mobilfunks – dar. Dazu wurde die neuere internationale wissenschaftliche Literatur umfassend gesichtet und die Ergebnisse aktueller nationaler und internationaler Forschungsprojekten daraufhin analysiert, ob relevante neue Erkenntnisse vorliegen, die die Diskussionen zu möglichen gesundheitlichen Risiken der HF-EMF substanziell verändern könnten. Ein weiterer Schwerpunkt lag auf Forschungsbemühungen, die einen substanziellen Beitrag zur verbesserten Risikobewertung der Exposition von jungen Menschen leisten wollen. Darüber hinaus diskutiert der Bericht relevante Aspekte der EMF-Risikogovernance (z.B. Öffentlichkeitsbeteiligung, Interessenkonflikte, Risikoinformation und -kommunikation) und beschreibt Optionen, wie im Kontext des EMF-Diskurses Barrieren für eine offene wechselseitige Kommunikation von Akteursgruppen – insbesondere zwischen Wissenschaft, Zivilgesellschaft und Politik – abgebaut werden können