Real-time Detection Of Bio-effects And Biological Robustness Analysis On Extremely Low Frequency Electromagnetic Fields

With rapid development of electrical equipments and high-voltage power transmission lines and popularity of various household appliances, health effects of extremely low frequency electromagnetic fields draws more and more attention. But there is no exact epidemiological evidence for human health effects of extremely low frequency electromagnetic fields. And the mechanism of biological effects of electromagnetic fields is especially important. There are two key questions in the research of the mechanism of biological effects of electromagnetic fields:(1) How do organisms and electromagnetic fields interact with each other especially at the earliest period?(2) How much strength of electromagnetic fields exposure can lead to biological or even healthy effect?To investigate biological effects of electromagnetic fields, we need dynamic, real-time, exact methods with high efficiency. Furthermore, we should evaluate the impact of EMF on organism from the angle of system theory.Based on previous work in our laboratory, we investigated the robustness of short-time stimulation of50Hz electromagnetic field of rat hippocampal nerve cells. With program we develop, dynamic variations of three cellular physiological indicators—reactive oxygen species (ROS), calcium ion (Ca2+) and mitochondrial membrane potential (MMP)—were analyzed.The main work of this paper includes the following two parts:The first part is developing the real-time detection technology of biological effects under extremely low frequency electromagnetic field exposure. Two analysis methods based on threshold segmentation technology are established. With first method, we draw graphs indicating the concentration of intracellular ROS and Ca2+based on time-series fluorescent photos. We obtained dynamic change of red and green fluorescence intensity of MMP with second method, and we found that the ratio of red and green fluorescence intensity can exactly show the stableness of MMP.The second part is the analysis of biological effects of extremely low frequency electromagnetic fields. Based on the dynamic graphs we obtained in the previous part, we engaged phase graphs for non-linear systems based on Lyapunov stability theory and determined physical states of each indicators of every targeted cell.Three points below were obtained in the thesis:(1) Short-time EMF stimulation can affect the intracellular ROS robustness of hippocampal neuron cells, and this affection shows an apparent does-effect relationship.(2) Calcium robustness of hippocampal neuron cells was also affected by short-time stimulation. Significant difference of robustness between cells with high and low intensity EMF stimulation was observed, but within each of the two groups, there is no obvious variation of Ca2+states, even different intensity of EMF stimulations were given. We assume that there might be a threshold of robustness against EMF stimulation.(3) Significant difference of robustness of MMP of cells with different intensity of EMF stimulations was not observed.