Urech M, Eicher B, Siegenthaler J
Puls Environmental Consulting, Bern, Switzerland.
Bioelectromagnetics. 1996;17(4):327-34. doi: 10.1002/(SICI)1521-186X(1996)17:4<327::AID-BEM9>3.0.CO;2-5.
The effects of electromagnetic fields on lichens were investigated. Field experiments of long duration (1-3 years) were combined with laboratory experiments and theoretical considerations. Samples of the lichen species Parmelia tiliacea and Hypogymnia physodes were exposed to microwaves (2.45 GHz; 0.2, 5, and 50 mW/cm2; and control). Both species showed a substantially reduced growth rate at 50 mW/cm2. A differentiation between thermal and nonthermal effects was not possible. Temperature measurements on lichens exposed to microwaves (2.45 GHz, 50 mW/cm2) showed a substantial increase in the surface temperature and an accelerated drying process. The thermal effect of microwave on lichens was verified. The exposure of lichens of both species was repeated near a short-wave broadcast transmitter (9.5 MHz, amplitude modulated; maximum field strength 235 V/m, 332 mA/m). No visible effects on the exposed lichens were detected. At this frequency, no thermal effects were expected, and the experimental results support this hypothesis. Theoretical estimates based on climatic data and literature showed that the growth reductions in the initial experiments could very likely have been caused by drying of the lichens from the heating with microwaves. The results of the other experiments support the hypothesis that the response of the lichens exposed to microwaves was mainly due to thermal effects and that there is a low probability of nonthermal effects.
研究了电磁场对地衣的影响。将长期（1 - 3年）的野外实验与实验室实验及理论思考相结合。地衣物种薄叶梅衣（Parmelia tiliacea）和绵腹皮果衣（Hypogymnia physodes）的样本暴露于微波（2.45 GHz；0.2、5和50 mW/cm²；以及对照组）。两种物种在50 mW/cm²时生长速率均大幅降低。无法区分热效应和非热效应。对地衣暴露于微波（2.45 GHz，50 mW/cm²）的温度测量显示表面温度大幅升高且干燥过程加速。证实了微波对地衣的热效应。在短波广播发射机（9.5 MHz，调幅；最大场强235 V/m，332 mA/m）附近重复对两种地衣的暴露。未检测到对暴露地衣有可见影响。在此频率下，预计无热效应，实验结果支持这一假设。基于气候数据和文献的理论估计表明，最初实验中的生长减少很可能是由微波加热导致地衣干燥引起的。其他实验结果支持以下假设：暴露于微波的地衣的反应主要是由于热效应，且非热效应的可能性较低。
