Indian Council of Medical Research (ICMR).
The deployment of 5G networks has reignited concerns about the biological impacts of radiofrequency electromagnetic fields (HF-EMF). Beyond the long-debated issue of carcinogenicity, increasing attention is now being paid to potential effects on reproductive health. Current regulatory limits primarily aim to prevent thermal tissue damage, while the non-thermal mechanisms and long-term effects of subthermal exposure remain poorly understood. The lower 5G frequency range (600–900 MHz), which is widely implemented in countries such as India, is particularly relevant. Previous studies on the reproductive effects of mobile phone radiation have produced inconsistent results and have largely focused on male physiology, leaving the impact on female reproduction understudied. Against this backdrop, the present study investigates the non-thermal effects of continuous wave 700 MHz RF radiation on reproductive function in female rats.
Adult female Wistar rats were exposed inside shielded chambers and divided into two exposure regimens: short-term (6 hours per day for 10 days, n = 6) and long-term (4 hours per day for 60 days, n = 8). Both groups received continuous, unmodulated 700 MHz RF radiation at a power density of 7.192 W/m², corresponding to a whole-body SAR of 0.375 W/kg. Each exposure group was compared with both sham-exposed and completely unexposed controls. Reproductive endpoints included estrous cycle length, serum levels of estradiol, progesterone, and testosterone, ovarian histopathology, and oxidative stress biomarkers, such as malondialdehyde (MDA), superoxide dismutase (SOD), and total antioxidant capacity (FRAP).Genotoxicity was assessed via comet assay.
Both exposure groups exhibited significant alterations in estrous cycle duration compared to controls. Serum testosterone levels were modestly yet significantly elevated in both groups, while estradiol and progesterone levels remained unchanged. Oxidative stress parameters revealed increased lipid peroxidation (MDA) and decreased antioxidant defense (SOD and FRAP) in both short- and long-term exposed animals. Histological examination of the ovaries of long-term exposed rats showed notable pathologies, including cystic follicles and abnormal vascular morphology. No genotoxic effects were detected under the applied exposure conditions.
These findings suggest that both brief (10‐day) and prolonged (60‐day) exposure to non-thermal 700 MHz RF radiation induces oxidative stress in the ovaries of female Wistar rats. However, significant histopathological alterations, such as cystic folliculogenesis and abnormal vasculature, were observed only following long‐term exposure, implying a cumulative effect. Although serum testosterone levels were elevated, they did not reach levels indicative of overt endocrine disruption. Similarly, despite disrupted estrous cyclicity, the absence of genotoxicity and mild changes in sex steroid concentrations argue against gross reproductive failure under these conditions. Nonetheless, the authors caution that non-thermal RF exposure below current safety thresholds may pose subtle risks to female reproductive health. They advocate for further research to delineate dose–response relationships and elucidate mechanistic pathways. (RH)
Editorial Note:
This study’s strength lies in its real-world relevance. It examines subthermal RF exposure using a commonly deployed 5G frequency. The study includes both sham-exposed and unexposed controls and combines hormonal, histological, and oxidative stress analyses. The observed induction of oxidative stress and the resulting ovarian changes are consistent with a growing body of literature on the effects of RF on reproductive tissues (Altun et al., 2018; Kaur et al., 2023; Yadav et al., 2021). However, the interpretation of hormonal shifts would have benefitted from analyzing steroidogenesis-related signaling pathways. In addition, while the 700 MHz frequency falls within the 5G spectrum, the use of unmodulated signals limits the applicability to real-world 5G exposure, which typically employ complex modulation schemes. Despite these limitations, the study provides valuable insights into the reproductive risks associated with low-intensity RF fields.
Altun G, Deniz ÖG, Yurt KK, Davis D, Kaplan S. (2018). Effects of mobile phone exposure on metabolomics in the male and female reproductive systems. Environmental Research, 167(February), 700–707. https://doi.org/10.1016/j.envres.2018.02.031
Kaur P, Rai U, Singh R. (2023). Genotoxic Risks to Male Reproductive Health from Radiofrequency Radiation. Cells, 12(4), 1–20. https://doi.org/10.3390/cells12040594
Yadav H, Rai U, Singh R. (2021). Radiofrequency radiation: A possible threat to male fertility. Reproductive Toxicology (Elmsford, N.Y.), 100, 90–100. https://doi.org/10.1016/j.reprotox.2021.01.007
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