Sommer AM, Grote K, Reinhardt T, Streckert J, Hansen V, Lerchl A. (2009). Effects of Radiofrequency Electromagnetic Fields (UMTS) on Reproduction and Development of Mice: A Multi-generation Study. Radiat. Res. 171, 89–95.
Although epidemiologic and laboratory studies have found no link between non-ionizing, non-thermal radiofrequency electromagnetic fields (RF EMFs) from mobile phones or base stations and cancer or malignant disease, public concerns still exist. New mobile phones that utilize UMTS (Universal Mobile Telecommunication Systems) technology operate at a much higher frequency than older models and few studies have investigated the health effects of UMTS.
The objective of the study was to investigate whether chronic exposure to UMTS affects the fertility and development of mice over four generations.
The first generation of mice consisted of 128 males and 256 females. One male and two females were randomly assigned to a cage receiving either sham UMTS exposure or exposure with power densities of 22 W/m2, 6.8 W/m2, or 1.35 W/m2. Due to differences in the numbers and size of mice at various stages of the experiment, values of the specific absorption rate (SAR), a measure of the rate at which RF energy is absorbed by the body, varied. One female per cage was killed humanely 18 days after mating to measure reproductive function. The pups of the other female were counted and weighed immediately after birth and after 7, 14, and 20 days. Motor function, coordination, and development were also measured in the pups. Once the pups were weaned, parents were humanely killed and reproductive function was measured. Consumption of food and water was recorded for each cage. This process was repeated 3 times resulting in data for 4 generations.
Water consumption was unaffected by exposure. However, exposed animals consumed less food than unexposed animals. The testicular and accessory gland weights and the total number and number of malformed sperm were not affected by exposure in males. The epididymis weights were slightly lower in males of the 2nd generation at the highest exposure level compared to the sham-exposed males. In females, the weights of the uteri, numbers of corpora lutea, numbers of resorptions, and numbers of fetuses found in the uteri 18 days after mating were not significantly affected by exposure. Fetal malformations were also unaffected by exposure and only fetuses of the 4th generation at exposures of 6.8 W/m2 had weights that were slightly higher than fetuses of mice at other exposures. Numbers and weights of pups, pup development, and pup survival did not differ between exposure groups.
Implications and Limitations
This experiment did not show that long-term exposure to RF EMF at the frequencies of the UMTS standard negatively influenced fertility and development in mice, which is in accordance with previous studies. The exposure values were chosen to represent acceptable SAR thresholds in humans both for the general public and for occupational exposure. The highest exposure value exceeded this threshold. However, results from animal studies do not necessarily directly apply to humans and must be interpreted cautiously. The observation of lower food consumption in exposed versus unexposed animals must also be interpreted with caution because food consumption did not decrease accordingly as dose increased.
This study found that RF EMF exposure at frequencies and SARs relevant for humans was not associated with risks for fertility and development in mice. The observed effects on food consumption deserve further attention.