Abstract：
Human exposure to radiofrequency electromagnetic fields (RF-EMF) is restricted to prevent thermal effects in the tissue. However, at very low intensity exposure \"non-thermal\" biological effects, like oxidative stress, DNA or chromosomal aberrations, etc. collectively termed genomic-instability can occur after few hours. Little is known about chronic (years long) exposure with non-thermal RF-EMF. We identified two neighboring housing estates in a rural region with residents exposed to either relatively low (control-group) or relatively high (exposed-group) RF-EMF emitted from nearby mobile phone base stations (MPBS). 24 healthy adults that lived in their homes at least for 5 years volunteered. The homes were surveyed for common types of EMF, blood samples were tested for oxidative status, transient DNA alterations, permanent chromosomal damage, and specific cancer related genetic markers, like MLL gene rearrangements. We documented possible confounders, like age, sex, nutrition, life-exposure to ionizing radiation (X-rays), occupational exposures, etc. The groups matched well, age, sex, lifestyle and occupational risk factors were similar. The years long exposure had no measurable effect on MLL gene rearrangements and c-Abl-gene transcription modification. Associated with higher exposure, we found higher levels of lipid oxidation and oxidative DNA-lesions, though not statistically significant. DNA double strand breaks, micronuclei, ring chromosomes, and acentric chromosomes were not significantly different between the groups. Chromosomal aberrations like dicentric chromosomes (p=0.007), chromatid gaps (p=0.019), chromosomal fragments (p<0.001) and the total of chromosomal aberrations (p<0.001) were significantly higher in the exposed group. No potential confounder interfered with these findings. Increased rates of chromosomal aberrations as linked to excess exposure with ionizing radiation may also occur with non-ionizing radiation exposure. Biological endpoints can be informative for designing exposure limitation strategies. Further research is warranted to investigate the dose-effect-relationship between both, exposure intensity and exposure time, to account for endpoint accumulations after years of exposure. As established for ionizing radiation, chromosomal aberrations could contribute to the definition of protection thresholds, as their rate reflects exposure intensity and exposure time.
摘要：
限制人体暴露于射频电磁场（RF-EMF）以防止组织中的热效应。然而,在极低强度暴露“非热”生物效应下，比如氧化应激，DNA或染色体畸变,等。统称为基因组不稳定性可以在几个小时后发生。关于非热RF-EMF的慢性（长达数年）暴露知之甚少。我们在农村地区确定了两个相邻的住宅区，居民暴露于从附近的移动电话基站（MPBS）发出的相对较低（对照组）或相对较高（暴露组）的RF-EMF。24名在家中生活至少5年的健康成年人自愿参加。对房屋进行了常见类型的EMF调查，血液样本进行氧化状态测试，短暂的DNA改变，永久性染色体损伤,和特定的癌症相关遗传标记，比如MLL基因重排.我们记录了可能的混杂因素，像年龄,性别,营养,生活暴露于电离辐射（X射线），职业暴露,等。小组匹配得很好，年龄,性别,生活方式和职业危险因素相似。多年的长期暴露对MLL基因重排和c-Abl基因转录修饰没有可测量的影响。与更高的暴露相关，我们发现更高水平的脂质氧化和氧化DNA损伤，虽然没有统计学意义。DNA双链断裂,微核,环状染色体，和无心染色体在各组之间没有显着差异。染色体畸变如双中心染色体（p=0.007），染色单体间隙(p=0.019)，暴露组的染色体片段(p<0.001)和总染色体畸变(p<0.001)显著高于暴露组.没有潜在的混淆者干扰这些发现。与电离辐射过度暴露有关的染色体畸变率增加也可能发生在非电离辐射暴露中。生物终点可以为设计暴露限制策略提供信息。需要进一步的研究来研究两者之间的剂量效应关系，曝光强度和曝光时间，考虑暴露多年后的终点积累。根据电离辐射的规定，染色体畸变可能有助于保护阈值的定义，因为它们的速率反映了暴露强度和暴露时间。
