Frei M R, Berger R E, Dusch S J, Guel V, Jauchem J R, Merritt J H, Stedham M A
Trinity University, San Antonio, Texas 78212, USA.
Bioelectromagnetics. 1998;19(1):20-31.
The purpose of this study was to determine whether chronic, low-level exposure of mammary-tumor-prone mice to 2450 MHz radiofrequency radiation (RFR) promotes an earlier onset (decreased latency), a greater total incidence, or a faster growth rate of mammary tumors. One hundred C3H/ HeJ mice were exposed in circularly polarized waveguides (CWG) for 18 months (20 h/day, 7 days/wk) to continuous-wave, 2450 MHz RFR at a whole body average specific absorption rate (SAR) of 0.3 W/kg; 100 mice were sham exposed. Before exposure, SARs were determined calorimetrically; during experimentation, SARs were monitored by differential power measurement. All animals were visually inspected twice daily and were removed from the CWG cages for a weekly inspection, palpation, and weighing. From the time of detection, tumor size was measured weekly. Animals that died spontaneously, became moribund, or were killed after 18 months of exposure were completely necropsied; tissues were fixed and subjected to histopathological evaluations. Results showed no significant difference in weight profiles between sham-irradiated and irradiated mice. Concerning mammary carcinomas, there was no significant difference between groups with respect to palpated tumor incidence (sham = 52%; irradiated = 44%), latency to tumor onset (sham = 62.3 +/- 1.2 wk; irradiated = 64.0 +/- 1.6 wk), and rate of tumor growth. In general, histopathological examination revealed no significant differences in numbers of malignant, metastatic, or benign neoplasms between the two groups; a significantly greater incidence of alveolar-bronchiolar adenoma in the sham-irradiated mice was the only exception. In addition, survival analysis showed no significant difference in cumulative percent survival between sham and irradiated animals. Thus, results indicate that under the conditions of this study, long-term, low-level exposure of mammary-tumor-prone mice to 2450 MHz RFR did not affect mammary tumor incidence, latency to tumor onset, tumor growth rate, or animal longevity when compared with sham-irradiated controls.
本研究的目的是确定易患乳腺肿瘤的小鼠长期低水平暴露于2450兆赫射频辐射（RFR）是否会促使乳腺肿瘤更早发病（潜伏期缩短）、总发病率更高或生长速度更快。100只C3H/HeJ小鼠在圆极化波导（CWG）中暴露18个月（每天20小时，每周7天），全身平均比吸收率（SAR）为0.3瓦/千克，接受连续波2450兆赫RFR照射；100只小鼠进行假照射。照射前，通过量热法测定比吸收率；实验期间，通过差分功率测量监测比吸收率。所有动物每天进行两次目视检查，并从CWG笼中取出进行每周检查、触诊和称重。从检测到肿瘤开始，每周测量肿瘤大小。在暴露18个月后自然死亡、濒死或被处死的动物进行全面尸检；组织固定后进行组织病理学评估。结果显示，假照射小鼠和照射小鼠的体重曲线无显著差异。关于乳腺癌，两组在触诊肿瘤发病率（假照射组=52%；照射组=44%）、肿瘤发病潜伏期（假照射组=62.3±1.2周；照射组=64.0±1.6周）和肿瘤生长速度方面无显著差异。总体而言，组织病理学检查显示两组之间恶性、转移性或良性肿瘤的数量无显著差异；唯一的例外是假照射小鼠中肺泡支气管腺瘤的发病率显著更高。此外，生存分析显示假照射动物和照射动物的累积生存率无显著差异。因此，结果表明，在本研究条件下，与假照射对照组相比，易患乳腺肿瘤的小鼠长期低水平暴露于2450兆赫RFR不会影响乳腺肿瘤发病率、肿瘤发病潜伏期、肿瘤生长速度或动物寿命。
