Long-Term, Low-Level Exposure of Mice Prone to Mammary Tumors to 435 MHz Radiofrequency Radiation

Abstract

The purpose of this study was to determine if chronic, low-level exposure of mice prone to mammary tumors to 435 MHz radiofrequency (RF) radiation promotes an earlier onset, a faster growth rate or a greater total incidence of mammary tumors than in sham-exposed controls. Two hundred female C3H/HeJ mice were exposed for 21 months (22 h/day, 7 days/week) to a horizontally polarized 435 MHz pulse-wave (1.0 micros pulse width, 1.0 kHz pulse rate) RF radiation environment with an incident power density of 1.0 mW/cm2 (SAR = 0.32 W/kg). An additional 200 mice were sham-exposed. Animals that died spontaneously, became moribund or were euthanized after 21 months of exposure were completely necropsied; tissues were subjected to histopathological examinations. Concerning mammary carcinomas, there were no significant differences between the two groups with respect to latency to tumor onset, tumor growth rate and overall tumor incidence. Histopathological examination revealed no significant differences in numbers of malignant, metastatic or benign neoplasms between groups. Survival probability was estimated by the Kaplan-Meier method; no significant difference between groups was noted (Cox's test). Under the conditions of this long-term study, low-level exposure of mice prone to mammary tumors to 435 MHz RF radiation did not affect the incidence of mammary tumors, tumor growth rate, latency to tumor onset or animal longevity when compared to sham-exposed controls.

Survival and cancer in laboratory mammals exposed to radiofrequency energy

“…Results reviewed here also show that long term, low level exposure ( 4 W/kg) to RF energy did not affect survival adversely [Chou et al, 1992;Liddle et al, 1994;Toler et al, 1997;Frei et al, 1998a,b;Adey et al, 1999Adey et al, , 2000Heikkinen et al, 2001;Zook and Simmens, …”

“…Four studies using the mouse mammary model in long term, low level exposure studies did not observe any effect of RF exposure on cancer development [Toler et al, 1997;Frei et al, 1998a,b;Jauchem et al, 2001]. In an experiment, similar to the lung cancer colony assay by Szmigielski et al [1982] in which sarcoma cells were injected into mice, Santini et al [1988] injected melanoma cells into mice and found no effect of either CW or PW fields (2450 MHz) at 1.2 W/kg on cancer development.…”

“…studies exposed animals to 1 W/kg for 20-22 h/day for long periods, ranging from 18-25 months [Chou et al, 1992;Toler et al, 1997;Frei et al, 1998a,b]. Six more recent studies exposed animals repeatedly to fields similar to mobile phone emissions for approximately 2 years, the average lifespan of mice and rats [Adey et al, 1999[Adey et al, , 2000Heikkinen et al, 2001;Zook and Simmens, 2001;Utteridge et al, 2002], or for about 6 months [Higashikubo et al, 1999].…”

“…There are a number of recent, well designed studies that show that RF exposure at SARs 4 W/kg for long periods (18-25 months) did not decrease survival [Chou et al, 1992;Toler et al, 1997;Frei et al, 1998a,b;Adey et al, 1999Adey et al, , 2000Heikkinen et al, 2001;Zook and Simmens, 2001;Utteridge et al, 2002]. For example, RF exposure (1 h/day, 5 days/week) of mice up to 2 years at 0.25, 1, 2, and 4 W/kg has been recently reported to have no affect on survival [Utteridge et al, 2002].…”

Radiofrequency exposure and mammalian cell toxicity, genotoxicity, and transformation

“…After histopathological examination of the thymus, lymph nodes (if enlarged), spleen, liver, lung, kidney, adrenal, large and small bowel, urogenital system, eyes, brain, and any tissue appearing abnormal at autopsy, no mention was made of any observation of RF induced tissue necrosis. Toler et al [1997] exposed female mammary cancer prone mice to a 435 MHz signal, pulse wave, with a 1.0 ms pulse width at a 1.0 kHz pulse repetition rate. The SAR reported was 0.32 W/kg.…”